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* [PATCH] merge-tree: add -X strategy option
@ 2023-08-05 14:24 Izzy via GitGitGadget
  2023-08-07  2:10 ` Junio C Hamano
  2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
  0 siblings, 2 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-08-05 14:24 UTC (permalink / raw)
  To: git; +Cc: Izzy, winglovet

From: winglovet <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically solve conflicts.

Signed-off-by: winglovet <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

 builtin/merge-tree.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..2ec6ec0d39a 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -19,6 +19,8 @@
 #include "tree.h"
 #include "config.h"
 
+static const char **xopts;
+static size_t xopts_nr, xopts_alloc;
 static int line_termination = '\n';
 
 struct merge_list {
@@ -414,6 +416,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
 
 	init_merge_options(&opt, the_repository);
 
+	opt.recursive_variant = o->merge_options.recursive_variant;
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
+static int option_parse_x(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		return 0;
+
+	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
+	xopts[xopts_nr++] = xstrdup(arg);
+	return 0;
+}
+
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
@@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_CALLBACK('X', "strategy-option", &xopts,
+			N_("option=value"),
+			N_("option for selected merge strategy"),
+			option_parse_x),
 		OPT_END()
 	};
 
@@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	for (int x = 0; x < xopts_nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts[x]))
+			die(_("unknown strategy option: -X%s"), xopts[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH] merge-tree: add -X strategy option
  2023-08-05 14:24 [PATCH] merge-tree: add -X strategy option Izzy via GitGitGadget
@ 2023-08-07  2:10 ` Junio C Hamano
  2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
  1 sibling, 0 replies; 27+ messages in thread
From: Junio C Hamano @ 2023-08-07  2:10 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Izzy, Elijah Newren

"Izzy via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: winglovet <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically solve conflicts.
>
> Signed-off-by: winglovet <winglovet@gmail.com>

cf. Documentation/SubmittingPatches::[real-name], a part of the DCO
section of the document.

>  builtin/merge-tree.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)

A new feature should be protected by new tests to make sure it will
not be broken accidentally by others.  Probably a couple of new
tests to both t4300 and t4301?

$ git shortlog -sn --no-merges --since=6.months builtin/merge-tree.c t/t430[01]*.sh

tells me that Elijah and Ævar had been active, but by looking at the
output of

$ git log --author=Ævar --since=6.months builtin/merge-tree.c t/t430[01]*.sh

shows that the contribution by the latter was solely about code
clean-up with Coccinelle and not about code features and correctness,
so for a new-feature change like this, I'd ask comments by Elijah if
I were writing this patch.

Thanks.

> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>  
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>  
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>  	int show_messages;
>  	int name_only;
>  	int use_stdin;
> +	struct merge_options merge_options;
>  };
>  
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>  
>  	init_merge_options(&opt, the_repository);
>  
> +	opt.recursive_variant = o->merge_options.recursive_variant;
> +
>  	opt.show_rename_progress = 0;
>  
>  	opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>  	return !result.clean; /* result.clean < 0 handled above */
>  }
>  
> +static int option_parse_x(const struct option *opt,
> +			  const char *arg, int unset)
> +{
> +	if (unset)
> +		return 0;
> +
> +	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +	xopts[xopts_nr++] = xstrdup(arg);
> +	return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>  	struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  			   &merge_base,
>  			   N_("commit"),
>  			   N_("specify a merge-base for the merge")),
> +		OPT_CALLBACK('X', "strategy-option", &xopts,
> +			N_("option=value"),
> +			N_("option for selected merge strategy"),
> +			option_parse_x),
>  		OPT_END()
>  	};
>  
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  	argc = parse_options(argc, argv, prefix, mt_options,
>  			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>  
> +	for (int x = 0; x < xopts_nr; x++)
> +		if (parse_merge_opt(&o.merge_options, xopts[x]))
> +			die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>  	/* Handle --stdin */
>  	if (o.use_stdin) {
>  		struct strbuf buf = STRBUF_INIT;
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb

^ permalink raw reply	[flat|nested] 27+ messages in thread

* [PATCH v2] merge-tree: add -X strategy option
  2023-08-05 14:24 [PATCH] merge-tree: add -X strategy option Izzy via GitGitGadget
  2023-08-07  2:10 ` Junio C Hamano
@ 2023-08-12  5:33 ` Izzy via GitGitGadget
  2023-08-12  5:41   ` 唐宇奕
                     ` (2 more replies)
  1 sibling, 3 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-08-12  5:33 UTC (permalink / raw)
  To: git; +Cc: Izzy, winglovet

From: winglovet <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically solve conflicts.

Signed-off-by: winglovet <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

Range-diff vs v1:

 1:  b843caed596 ! 1:  7d53d08381e merge-tree: add -X strategy option
     @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
       	/* Handle --stdin */
       	if (o.use_stdin) {
       		struct strbuf buf = STRBUF_INIT;
     +
     + ## t/t4301-merge-tree-write-tree.sh ##
     +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
     + 	git branch side1 &&
     + 	git branch side2 &&
     + 	git branch side3 &&
     ++	git branch side4 &&
     + 
     + 	git checkout side1 &&
     + 	test_write_lines 1 2 3 4 5 6 >numbers &&
     +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
     + 	test_tick &&
     + 	git commit -m rename-numbers &&
     + 
     ++	git checkout side4 &&
     ++	test_write_lines 0 1 2 3 4 5 >numbers &&
     ++	echo yo >greeting &&
     ++	git add numbers greeting &&
     ++	test_tick &&
     ++	git commit -m other-content-modifications &&
     ++
     + 	git switch --orphan unrelated &&
     + 	>something-else &&
     + 	git add something-else &&
     +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few conflicts' '
     + 	test_cmp expect actual
     + '
     + 
     ++test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
     ++	git checkout side1^0 &&
     ++
     ++	# make sure merge conflict exists
     ++	test_must_fail git merge side4 &&
     ++	git merge --abort &&
     ++
     ++	git merge -X ours side4 &&
     ++	git rev-parse HEAD^{tree} > expected &&
     ++
     ++    git merge-tree -X ours side1 side4 > actual &&
     ++
     ++	test_cmp expected actual
     ++'
     ++
     + test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
     + 	# Mis-spell with single "s" instead of double "s"
     + 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&


 builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
 t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..2ec6ec0d39a 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -19,6 +19,8 @@
 #include "tree.h"
 #include "config.h"
 
+static const char **xopts;
+static size_t xopts_nr, xopts_alloc;
 static int line_termination = '\n';
 
 struct merge_list {
@@ -414,6 +416,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
 
 	init_merge_options(&opt, the_repository);
 
+	opt.recursive_variant = o->merge_options.recursive_variant;
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
+static int option_parse_x(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		return 0;
+
+	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
+	xopts[xopts_nr++] = xstrdup(arg);
+	return 0;
+}
+
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
@@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_CALLBACK('X', "strategy-option", &xopts,
+			N_("option=value"),
+			N_("option for selected merge strategy"),
+			option_parse_x),
 		OPT_END()
 	};
 
@@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	for (int x = 0; x < xopts_nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts[x]))
+			die(_("unknown strategy option: -X%s"), xopts[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b..2718817628c 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
 	git branch side1 &&
 	git branch side2 &&
 	git branch side3 &&
+	git branch side4 &&
 
 	git checkout side1 &&
 	test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m rename-numbers &&
 
+	git checkout side4 &&
+	test_write_lines 0 1 2 3 4 5 >numbers &&
+	echo yo >greeting &&
+	git add numbers greeting &&
+	test_tick &&
+	git commit -m other-content-modifications &&
+
 	git switch --orphan unrelated &&
 	>something-else &&
 	git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
 	test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
+	git checkout side1^0 &&
+
+	# make sure merge conflict exists
+	test_must_fail git merge side4 &&
+	git merge --abort &&
+
+	git merge -X ours side4 &&
+	git rev-parse HEAD^{tree} > expected &&
+
+    git merge-tree -X ours side1 side4 > actual &&
+
+	test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
 	# Mis-spell with single "s" instead of double "s"
 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v2] merge-tree: add -X strategy option
  2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
@ 2023-08-12  5:41   ` 唐宇奕
  2023-09-03  1:31     ` 唐宇奕
  2023-09-12 15:03   ` Elijah Newren
  2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
  2 siblings, 1 reply; 27+ messages in thread
From: 唐宇奕 @ 2023-08-12  5:41 UTC (permalink / raw)
  To: Izzy via GitGitGadget, Junio C Hamano; +Cc: git, newren

Thanks for your advice, I have uploaded a new patch including tests.

On Sat, Aug 12, 2023 at 1:33 PM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: winglovet <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically solve conflicts.
>
> Signed-off-by: winglovet <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v1:
>
>  1:  b843caed596 ! 1:  7d53d08381e merge-tree: add -X strategy option
>      @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
>      +
>      + ## t/t4301-merge-tree-write-tree.sh ##
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
>      +  git branch side1 &&
>      +  git branch side2 &&
>      +  git branch side3 &&
>      ++ git branch side4 &&
>      +
>      +  git checkout side1 &&
>      +  test_write_lines 1 2 3 4 5 6 >numbers &&
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
>      +  test_tick &&
>      +  git commit -m rename-numbers &&
>      +
>      ++ git checkout side4 &&
>      ++ test_write_lines 0 1 2 3 4 5 >numbers &&
>      ++ echo yo >greeting &&
>      ++ git add numbers greeting &&
>      ++ test_tick &&
>      ++ git commit -m other-content-modifications &&
>      ++
>      +  git switch --orphan unrelated &&
>      +  >something-else &&
>      +  git add something-else &&
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few conflicts' '
>      +  test_cmp expect actual
>      + '
>      +
>      ++test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
>      ++ git checkout side1^0 &&
>      ++
>      ++ # make sure merge conflict exists
>      ++ test_must_fail git merge side4 &&
>      ++ git merge --abort &&
>      ++
>      ++ git merge -X ours side4 &&
>      ++ git rev-parse HEAD^{tree} > expected &&
>      ++
>      ++    git merge-tree -X ours side1 side4 > actual &&
>      ++
>      ++ test_cmp expected actual
>      ++'
>      ++
>      + test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>      +  # Mis-spell with single "s" instead of double "s"
>      +  test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..2718817628c 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&
> +
> +    git merge-tree -X ours side1 side4 > actual &&
> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
> --
> gitgitgadget

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v2] merge-tree: add -X strategy option
  2023-08-12  5:41   ` 唐宇奕
@ 2023-09-03  1:31     ` 唐宇奕
  0 siblings, 0 replies; 27+ messages in thread
From: 唐宇奕 @ 2023-09-03  1:31 UTC (permalink / raw)
  To: Izzy via GitGitGadget, Junio C Hamano; +Cc: git, newren

Hello, is there any problem with this patch?

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v2] merge-tree: add -X strategy option
  2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
  2023-08-12  5:41   ` 唐宇奕
@ 2023-09-12 15:03   ` Elijah Newren
  2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
  2 siblings, 0 replies; 27+ messages in thread
From: Elijah Newren @ 2023-09-12 15:03 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, winglovet

Hi,

Sorry for the delay in responding; I've been busy with non-git things...

On Sat, Aug 12, 2023 at 12:19 AM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: winglovet <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically solve conflicts.
>
> Signed-off-by: winglovet <winglovet@gmail.com>

Junio already flagged this line in your v1; you either need to correct
it or respond to his comments about it.

> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v2
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v2
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v1:
>
>  1:  b843caed596 ! 1:  7d53d08381e merge-tree: add -X strategy option
>      @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
>      +
>      + ## t/t4301-merge-tree-write-tree.sh ##
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
>      +  git branch side1 &&
>      +  git branch side2 &&
>      +  git branch side3 &&
>      ++ git branch side4 &&
>      +
>      +  git checkout side1 &&
>      +  test_write_lines 1 2 3 4 5 6 >numbers &&
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success setup '
>      +  test_tick &&
>      +  git commit -m rename-numbers &&
>      +
>      ++ git checkout side4 &&
>      ++ test_write_lines 0 1 2 3 4 5 >numbers &&
>      ++ echo yo >greeting &&
>      ++ git add numbers greeting &&
>      ++ test_tick &&
>      ++ git commit -m other-content-modifications &&
>      ++
>      +  git switch --orphan unrelated &&
>      +  >something-else &&
>      +  git add something-else &&
>      +@@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few conflicts' '
>      +  test_cmp expect actual
>      + '
>      +
>      ++test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
>      ++ git checkout side1^0 &&
>      ++
>      ++ # make sure merge conflict exists
>      ++ test_must_fail git merge side4 &&
>      ++ git merge --abort &&
>      ++
>      ++ git merge -X ours side4 &&
>      ++ git rev-parse HEAD^{tree} > expected &&
>      ++
>      ++    git merge-tree -X ours side1 side4 > actual &&
>      ++
>      ++ test_cmp expected actual
>      ++'
>      ++
>      + test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>      +  # Mis-spell with single "s" instead of double "s"
>      +  test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;

I know we already have lots of globals, and I'm partially to blame
since I also copied this style from elsewhere into this file, but it'd
sure be nice to get rid of these needless globals rather than add
more.  But, certainly not a blocker....

>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };

Probably the best we can do now, but feels a little icky to me that
parse_merge_opt() works on all of struct merge_options rather than
having a dedicated struct for the particular options it can set.  Made
sense back in the merge-recursive.[ch] days, but it provides too many
extra unrelated and unnecessary fields now.

This isn't something you need to fix in this patch, though, just
something else I'll keep in mind when I get back to working on
removing merge-recursive.[ch].

>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..2718817628c 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" stragety option' '

stragety -> strategy

> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&

Style: '>filename', not '> filename'.

> +
> +    git merge-tree -X ours side1 side4 > actual &&

Same style issue with redirect.

Also, why is the leading spacing inconsistent with the surrounding lines?

> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

I personally don't see the value in passing `-X ours` or `-X theirs`
to merges.  I've never really been a fan of either.  Granted, I
understand the value in making merge-tree support the same things that
existing merges support, so I'm fine with supporting it, but I'd
rather have a useful example for the testcase such as
-Xignore-space-change or something (or maybe use it as an additional
example?)  Not a blocker on its own, but just a personal preference.

Anyway, the general direction of the patch seems reasonable.  Not
everything I commented on needs to be fixed, as I noted, but there are
a few small things to fix up.

^ permalink raw reply	[flat|nested] 27+ messages in thread

* [PATCH v3] merge-tree: add -X strategy option
  2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
  2023-08-12  5:41   ` 唐宇奕
  2023-09-12 15:03   ` Elijah Newren
@ 2023-09-16  2:14   ` Izzy via GitGitGadget
  2023-09-16  2:26     ` 唐宇奕
                       ` (2 more replies)
  2 siblings, 3 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-09-16  2:14 UTC (permalink / raw)
  To: git; +Cc: Elijah Newren, Izzy, Tang Yuyi

From: Tang Yuyi <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically solve conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

Range-diff vs v2:

 1:  7d53d08381e ! 1:  d64a774fa7c merge-tree: add -X strategy option
     @@
       ## Metadata ##
     -Author: winglovet <winglovet@gmail.com>
     +Author: Tang Yuyi <winglovet@gmail.com>
      
       ## Commit message ##
          merge-tree: add -X strategy option
     @@ Commit message
          Add merge strategy option to produce more customizable merge result such
          as automatically solve conflicts.
      
     -    Signed-off-by: winglovet <winglovet@gmail.com>
     +    Signed-off-by: Tang Yuyi <winglovet@gmail.com>
      
       ## builtin/merge-tree.c ##
      @@
     @@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few c
       	test_cmp expect actual
       '
       
     -+test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
     ++test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
      +	git checkout side1^0 &&
      +
      +	# make sure merge conflict exists


 builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
 t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..2ec6ec0d39a 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -19,6 +19,8 @@
 #include "tree.h"
 #include "config.h"
 
+static const char **xopts;
+static size_t xopts_nr, xopts_alloc;
 static int line_termination = '\n';
 
 struct merge_list {
@@ -414,6 +416,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
 
 	init_merge_options(&opt, the_repository);
 
+	opt.recursive_variant = o->merge_options.recursive_variant;
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
+static int option_parse_x(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		return 0;
+
+	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
+	xopts[xopts_nr++] = xstrdup(arg);
+	return 0;
+}
+
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
@@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_CALLBACK('X', "strategy-option", &xopts,
+			N_("option=value"),
+			N_("option for selected merge strategy"),
+			option_parse_x),
 		OPT_END()
 	};
 
@@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	for (int x = 0; x < xopts_nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts[x]))
+			die(_("unknown strategy option: -X%s"), xopts[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b..4125bb101ec 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
 	git branch side1 &&
 	git branch side2 &&
 	git branch side3 &&
+	git branch side4 &&
 
 	git checkout side1 &&
 	test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m rename-numbers &&
 
+	git checkout side4 &&
+	test_write_lines 0 1 2 3 4 5 >numbers &&
+	echo yo >greeting &&
+	git add numbers greeting &&
+	test_tick &&
+	git commit -m other-content-modifications &&
+
 	git switch --orphan unrelated &&
 	>something-else &&
 	git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
 	test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
+	git checkout side1^0 &&
+
+	# make sure merge conflict exists
+	test_must_fail git merge side4 &&
+	git merge --abort &&
+
+	git merge -X ours side4 &&
+	git rev-parse HEAD^{tree} > expected &&
+
+    git merge-tree -X ours side1 side4 > actual &&
+
+	test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
 	# Mis-spell with single "s" instead of double "s"
 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v3] merge-tree: add -X strategy option
  2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
@ 2023-09-16  2:26     ` 唐宇奕
  2023-09-16  3:21       ` Elijah Newren
  2023-09-16  3:16     ` Elijah Newren
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
  2 siblings, 1 reply; 27+ messages in thread
From: 唐宇奕 @ 2023-09-16  2:26 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Elijah Newren

Thanks for your advice!
I've fixed those blocking issues.
However, regarding the global variable issue, I'm not familiar with C
and git code and don't know how to solve this. I think perhaps we need
something like closure to parse opt into a local variable?
Our usecase is to achieve something like 'range-diff', we first use
merge-tree to merge new patchset's base commit with old patchset's
source commit, then use the merge result to diff against new
patchset's source commit. So we only need to make sure conflict's are
handled automatically, leaving other diff features to the second step.


On Sat, Sep 16, 2023 at 10:14 AM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Tang Yuyi <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically solve conflicts.
>
> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v3
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v3
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v2:
>
>  1:  7d53d08381e ! 1:  d64a774fa7c merge-tree: add -X strategy option
>      @@
>        ## Metadata ##
>      -Author: winglovet <winglovet@gmail.com>
>      +Author: Tang Yuyi <winglovet@gmail.com>
>
>        ## Commit message ##
>           merge-tree: add -X strategy option
>      @@ Commit message
>           Add merge strategy option to produce more customizable merge result such
>           as automatically solve conflicts.
>
>      -    Signed-off-by: winglovet <winglovet@gmail.com>
>      +    Signed-off-by: Tang Yuyi <winglovet@gmail.com>
>
>        ## builtin/merge-tree.c ##
>       @@
>      @@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few c
>         test_cmp expect actual
>        '
>
>      -+test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
>      ++test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
>       + git checkout side1^0 &&
>       +
>       + # make sure merge conflict exists
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..4125bb101ec 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&
> +
> +    git merge-tree -X ours side1 side4 > actual &&
> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
> --
> gitgitgadget

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v3] merge-tree: add -X strategy option
  2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
  2023-09-16  2:26     ` 唐宇奕
@ 2023-09-16  3:16     ` Elijah Newren
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
  2 siblings, 0 replies; 27+ messages in thread
From: Elijah Newren @ 2023-09-16  3:16 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: Git Mailing List, Tang Yuyi

Hi,

On Fri, Sep 15, 2023 at 7:14 PM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Tang Yuyi <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically solve conflicts.

s/solve/resolving/

I think "solve" should be "solving" here, except that "solve" isn't
really the right word.  It's not solving (figuring out) anything, it's
using a big hammer to make the problem just go away.  So, I think
"resolving" is a better choice.

> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v3
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v3
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v2:
>
>  1:  7d53d08381e ! 1:  d64a774fa7c merge-tree: add -X strategy option
>      @@
>        ## Metadata ##
>      -Author: winglovet <winglovet@gmail.com>
>      +Author: Tang Yuyi <winglovet@gmail.com>
>
>        ## Commit message ##
>           merge-tree: add -X strategy option
>      @@ Commit message
>           Add merge strategy option to produce more customizable merge result such
>           as automatically solve conflicts.
>
>      -    Signed-off-by: winglovet <winglovet@gmail.com>
>      +    Signed-off-by: Tang Yuyi <winglovet@gmail.com>
>
>        ## builtin/merge-tree.c ##
>       @@
>      @@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few c
>         test_cmp expect actual
>        '
>
>      -+test_expect_success 'Auto resolve conflicts by "ours" stragety option' '
>      ++test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
>       + git checkout side1^0 &&
>       +
>       + # make sure merge conflict exists
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..4125bb101ec 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&
> +
> +    git merge-tree -X ours side1 side4 > actual &&

Multiple style problems still here from V2:
  * There should be no space between the redirection operator ('>')
and the filename following it.
  * You have indented most lines with tabs, but the line just above
this one with 4 spaces.


> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v3] merge-tree: add -X strategy option
  2023-09-16  2:26     ` 唐宇奕
@ 2023-09-16  3:21       ` Elijah Newren
  0 siblings, 0 replies; 27+ messages in thread
From: Elijah Newren @ 2023-09-16  3:21 UTC (permalink / raw)
  To: 唐宇奕; +Cc: Izzy via GitGitGadget, git

On Fri, Sep 15, 2023 at 7:27 PM 唐宇奕 <winglovet@gmail.com> wrote:
>
> Thanks for your advice!
> I've fixed those blocking issues.

Thanks, you did fix most of them.  I left a comment on a few things on V3.

> However, regarding the global variable issue, I'm not familiar with C
> and git code and don't know how to solve this. I think perhaps we need
> something like closure to parse opt into a local variable?

You could merely make xopts, xopts_nr, and xopts_alloc local
variables, and pass them around as needed.  Closures would make things
look cleaner perhaps, but certainly aren't necessarily.

But, I don't think the globals thing is a blocking issue, especially
since we already have a number of unnecessary globals in that file
already.

> Our usecase is to achieve something like 'range-diff', we first use
> merge-tree to merge new patchset's base commit with old patchset's
> source commit, then use the merge result to diff against new
> patchset's source commit. So we only need to make sure conflict's are
> handled automatically, leaving other diff features to the second step.

If you're trying to do something like range-diff, then I don't see why
there's any point in creating a merge at all.  I'm afraid I don't
follow your explanations about the steps you are taking and more
importantly why you are taking them, and how it helps you achieve your
goal of doing "something like 'range-diff'".  Could you elaborate?

^ permalink raw reply	[flat|nested] 27+ messages in thread

* [PATCH v4] merge-tree: add -X strategy option
  2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
  2023-09-16  2:26     ` 唐宇奕
  2023-09-16  3:16     ` Elijah Newren
@ 2023-09-16  3:47     ` Izzy via GitGitGadget
  2023-09-16  3:55       ` Elijah Newren
                         ` (3 more replies)
  2 siblings, 4 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-09-16  3:47 UTC (permalink / raw)
  To: git; +Cc: Elijah Newren, Izzy, Tang Yuyi

From: Tang Yuyi <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically resolving conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v4
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v4
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

Range-diff vs v3:

 1:  d64a774fa7c ! 1:  d2d8fcc2e9b merge-tree: add -X strategy option
     @@ Commit message
          merge-tree: add -X strategy option
      
          Add merge strategy option to produce more customizable merge result such
     -    as automatically solve conflicts.
     +    as automatically resolving conflicts.
      
          Signed-off-by: Tang Yuyi <winglovet@gmail.com>
      


 builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
 t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..2ec6ec0d39a 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -19,6 +19,8 @@
 #include "tree.h"
 #include "config.h"
 
+static const char **xopts;
+static size_t xopts_nr, xopts_alloc;
 static int line_termination = '\n';
 
 struct merge_list {
@@ -414,6 +416,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
 
 	init_merge_options(&opt, the_repository);
 
+	opt.recursive_variant = o->merge_options.recursive_variant;
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
+static int option_parse_x(const struct option *opt,
+			  const char *arg, int unset)
+{
+	if (unset)
+		return 0;
+
+	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
+	xopts[xopts_nr++] = xstrdup(arg);
+	return 0;
+}
+
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
@@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_CALLBACK('X', "strategy-option", &xopts,
+			N_("option=value"),
+			N_("option for selected merge strategy"),
+			option_parse_x),
 		OPT_END()
 	};
 
@@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	for (int x = 0; x < xopts_nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts[x]))
+			die(_("unknown strategy option: -X%s"), xopts[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b..4125bb101ec 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
 	git branch side1 &&
 	git branch side2 &&
 	git branch side3 &&
+	git branch side4 &&
 
 	git checkout side1 &&
 	test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m rename-numbers &&
 
+	git checkout side4 &&
+	test_write_lines 0 1 2 3 4 5 >numbers &&
+	echo yo >greeting &&
+	git add numbers greeting &&
+	test_tick &&
+	git commit -m other-content-modifications &&
+
 	git switch --orphan unrelated &&
 	>something-else &&
 	git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
 	test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
+	git checkout side1^0 &&
+
+	# make sure merge conflict exists
+	test_must_fail git merge side4 &&
+	git merge --abort &&
+
+	git merge -X ours side4 &&
+	git rev-parse HEAD^{tree} > expected &&
+
+    git merge-tree -X ours side1 side4 > actual &&
+
+	test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
 	# Mis-spell with single "s" instead of double "s"
 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v4] merge-tree: add -X strategy option
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
@ 2023-09-16  3:55       ` Elijah Newren
  2023-09-16  4:04       ` 唐宇奕
                         ` (2 subsequent siblings)
  3 siblings, 0 replies; 27+ messages in thread
From: Elijah Newren @ 2023-09-16  3:55 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Tang Yuyi

Hi,

On Fri, Sep 15, 2023 at 8:47 PM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Tang Yuyi <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically resolving conflicts.
>
> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v4
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v4
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v3:
>
>  1:  d64a774fa7c ! 1:  d2d8fcc2e9b merge-tree: add -X strategy option
>      @@ Commit message
>           merge-tree: add -X strategy option
>
>           Add merge strategy option to produce more customizable merge result such
>      -    as automatically solve conflicts.
>      +    as automatically resolving conflicts.

Thanks for fixing this part of what I pointed out in the review.

>           Signed-off-by: Tang Yuyi <winglovet@gmail.com>
>
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..4125bb101ec 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&
> +
> +    git merge-tree -X ours side1 side4 > actual &&

Please fix the problems in these last two lines as pointed out in both
of my last two reviews.

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v4] merge-tree: add -X strategy option
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
  2023-09-16  3:55       ` Elijah Newren
@ 2023-09-16  4:04       ` 唐宇奕
  2023-09-16  6:11       ` Jeff King
  2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
  3 siblings, 0 replies; 27+ messages in thread
From: 唐宇奕 @ 2023-09-16  4:04 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Elijah Newren

Thanks, what we want to do is to compare two patchsets' diff while
providing capabilities like normal commit diff.
The existing range-diff command provide an effective solution, however:
* The output isn't suitable for machine processing
* The command take's number of commits and commit messages into count,
while what we really want is merely the content diff
* The command doesn't support features like word diff, ignoring
whitespace changes, etc
So what comes to our mind is to simulate user behavior. We first merge
the old patchset into the new patchset's base commit, then use the
merge result to diff against the new patchset's source commit.
By doing this, the diff introduced between two patchsets' bases won't
be shown. Thus we get the 'real diff' between two patchsets.
In the first step, we use git-merge-tree to produce the merge result
since its performance's better than git-merge.
However, sometimes there's conflict between the new patchset's base
and the old patchset's source.So we need automatic conflict resolving
- only use content from 'their' side specifically.
Hope that makes sense.

On Sat, Sep 16, 2023 at 11:47 AM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Tang Yuyi <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically resolving conflicts.
>
> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v4
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v4
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v3:
>
>  1:  d64a774fa7c ! 1:  d2d8fcc2e9b merge-tree: add -X strategy option
>      @@ Commit message
>           merge-tree: add -X strategy option
>
>           Add merge strategy option to produce more customizable merge result such
>      -    as automatically solve conflicts.
>      +    as automatically resolving conflicts.
>
>           Signed-off-by: Tang Yuyi <winglovet@gmail.com>
>
>
>
>  builtin/merge-tree.c             | 24 ++++++++++++++++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..2ec6ec0d39a 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -19,6 +19,8 @@
>  #include "tree.h"
>  #include "config.h"
>
> +static const char **xopts;
> +static size_t xopts_nr, xopts_alloc;
>  static int line_termination = '\n';
>
>  struct merge_list {
> @@ -414,6 +416,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +442,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -510,6 +515,17 @@ static int real_merge(struct merge_tree_options *o,
>         return !result.clean; /* result.clean < 0 handled above */
>  }
>
> +static int option_parse_x(const struct option *opt,
> +                         const char *arg, int unset)
> +{
> +       if (unset)
> +               return 0;
> +
> +       ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +       xopts[xopts_nr++] = xstrdup(arg);
> +       return 0;
> +}
> +
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> @@ -548,6 +564,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_CALLBACK('X', "strategy-option", &xopts,
> +                       N_("option=value"),
> +                       N_("option for selected merge strategy"),
> +                       option_parse_x),
>                 OPT_END()
>         };
>
> @@ -556,6 +576,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts_nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..4125bb101ec 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} > expected &&
> +
> +    git merge-tree -X ours side1 side4 > actual &&
> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
> --
> gitgitgadget

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v4] merge-tree: add -X strategy option
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
  2023-09-16  3:55       ` Elijah Newren
  2023-09-16  4:04       ` 唐宇奕
@ 2023-09-16  6:11       ` Jeff King
  2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
  3 siblings, 0 replies; 27+ messages in thread
From: Jeff King @ 2023-09-16  6:11 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Elijah Newren, Izzy

On Sat, Sep 16, 2023 at 03:47:05AM +0000, Izzy via GitGitGadget wrote:

> +static int option_parse_x(const struct option *opt,
> +			  const char *arg, int unset)
> +{
> +	if (unset)
> +		return 0;
> +
> +	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
> +	xopts[xopts_nr++] = xstrdup(arg);
> +	return 0;
> +}

This callback was presumably copied from the one in builtin/merge.c, and
it suffers from the same "--no-strategy-option" bug. You should make a
similar change here to the one we did in dee02da826 (merge: make xopts a
strvec, 2023-08-31). And as a bonus, it will make your patch even
shorter. :)

It would also make it easier to get rid of the global variables, I
think. Something like (squashed into your patch):

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 2ec6ec0d39..e13dbc4c79 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -18,9 +18,8 @@
 #include "quote.h"
 #include "tree.h"
 #include "config.h"
+#include "strvec.h"
 
-static const char **xopts;
-static size_t xopts_nr, xopts_alloc;
 static int line_termination = '\n';
 
 struct merge_list {
@@ -515,20 +514,10 @@ static int real_merge(struct merge_tree_options *o,
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
-static int option_parse_x(const struct option *opt,
-			  const char *arg, int unset)
-{
-	if (unset)
-		return 0;
-
-	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
-	xopts[xopts_nr++] = xstrdup(arg);
-	return 0;
-}
-
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
+	struct strvec xopts = STRVEC_INIT;
 	int expected_remaining_argc;
 	int original_argc;
 	const char *merge_base = NULL;
@@ -564,10 +553,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
-		OPT_CALLBACK('X', "strategy-option", &xopts,
-			N_("option=value"),
-			N_("option for selected merge strategy"),
-			option_parse_x),
+		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
+			   N_("option for selected merge strategy")),
 		OPT_END()
 	};
 
@@ -576,9 +563,9 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
-	for (int x = 0; x < xopts_nr; x++)
-		if (parse_merge_opt(&o.merge_options, xopts[x]))
-			die(_("unknown strategy option: -X%s"), xopts[x]);
+	for (int x = 0; x < xopts.nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
+			die(_("unknown strategy option: -X%s"), xopts.v[x]);
 
 	/* Handle --stdin */
 	if (o.use_stdin) {

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* [PATCH v5] merge-tree: add -X strategy option
  2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
                         ` (2 preceding siblings ...)
  2023-09-16  6:11       ` Jeff King
@ 2023-09-16  8:37       ` Izzy via GitGitGadget
  2023-09-16  8:38         ` 唐宇奕
                           ` (2 more replies)
  3 siblings, 3 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-09-16  8:37 UTC (permalink / raw)
  To: git; +Cc: Elijah Newren, Jeff King, Izzy, Tang Yuyi

From: Tang Yuyi <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically resolving conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v5
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

Range-diff vs v4:

 1:  d2d8fcc2e9b ! 1:  28d4282e0d8 merge-tree: add -X strategy option
     @@ Commit message
      
       ## builtin/merge-tree.c ##
      @@
     + #include "quote.h"
       #include "tree.h"
       #include "config.h"
     ++#include "strvec.h"
       
     -+static const char **xopts;
     -+static size_t xopts_nr, xopts_alloc;
       static int line_termination = '\n';
       
     - struct merge_list {
      @@ builtin/merge-tree.c: struct merge_tree_options {
       	int show_messages;
       	int name_only;
     @@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
       
       	opt.branch1 = branch1;
      @@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
     - 	return !result.clean; /* result.clean < 0 handled above */
     - }
     - 
     -+static int option_parse_x(const struct option *opt,
     -+			  const char *arg, int unset)
     -+{
     -+	if (unset)
     -+		return 0;
     -+
     -+	ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
     -+	xopts[xopts_nr++] = xstrdup(arg);
     -+	return 0;
     -+}
     -+
       int cmd_merge_tree(int argc, const char **argv, const char *prefix)
       {
       	struct merge_tree_options o = { .show_messages = -1 };
     ++	struct strvec xopts = STRVEC_INIT;
     + 	int expected_remaining_argc;
     + 	int original_argc;
     + 	const char *merge_base = NULL;
      @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
       			   &merge_base,
       			   N_("commit"),
       			   N_("specify a merge-base for the merge")),
     -+		OPT_CALLBACK('X', "strategy-option", &xopts,
     -+			N_("option=value"),
     -+			N_("option for selected merge strategy"),
     -+			option_parse_x),
     ++		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
     ++			N_("option for selected merge strategy")),
       		OPT_END()
       	};
       
     @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
       	argc = parse_options(argc, argv, prefix, mt_options,
       			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
       
     -+	for (int x = 0; x < xopts_nr; x++)
     -+		if (parse_merge_opt(&o.merge_options, xopts[x]))
     -+			die(_("unknown strategy option: -X%s"), xopts[x]);
     ++	for (int x = 0; x < xopts.nr; x++)
     ++		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
     ++			die(_("unknown strategy option: -X%s"), xopts.v[x]);
      +
       	/* Handle --stdin */
       	if (o.use_stdin) {
     @@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few c
      +	git merge --abort &&
      +
      +	git merge -X ours side4 &&
     -+	git rev-parse HEAD^{tree} > expected &&
     ++	git rev-parse HEAD^{tree} >expected &&
      +
     -+    git merge-tree -X ours side1 side4 > actual &&
     ++	git merge-tree -X ours side1 side4 >actual &&
      +
      +	test_cmp expected actual
      +'


 builtin/merge-tree.c             | 11 +++++++++++
 t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..97d0fe6c952 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -18,6 +18,7 @@
 #include "quote.h"
 #include "tree.h"
 #include "config.h"
+#include "strvec.h"
 
 static int line_termination = '\n';
 
@@ -414,6 +415,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -439,6 +441,8 @@ static int real_merge(struct merge_tree_options *o,
 
 	init_merge_options(&opt, the_repository);
 
+	opt.recursive_variant = o->merge_options.recursive_variant;
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -513,6 +517,7 @@ static int real_merge(struct merge_tree_options *o,
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
+	struct strvec xopts = STRVEC_INIT;
 	int expected_remaining_argc;
 	int original_argc;
 	const char *merge_base = NULL;
@@ -548,6 +553,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
+			N_("option for selected merge strategy")),
 		OPT_END()
 	};
 
@@ -556,6 +563,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	for (int x = 0; x < xopts.nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
+			die(_("unknown strategy option: -X%s"), xopts.v[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b..b2c8a43fce3 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
 	git branch side1 &&
 	git branch side2 &&
 	git branch side3 &&
+	git branch side4 &&
 
 	git checkout side1 &&
 	test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m rename-numbers &&
 
+	git checkout side4 &&
+	test_write_lines 0 1 2 3 4 5 >numbers &&
+	echo yo >greeting &&
+	git add numbers greeting &&
+	test_tick &&
+	git commit -m other-content-modifications &&
+
 	git switch --orphan unrelated &&
 	>something-else &&
 	git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
 	test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
+	git checkout side1^0 &&
+
+	# make sure merge conflict exists
+	test_must_fail git merge side4 &&
+	git merge --abort &&
+
+	git merge -X ours side4 &&
+	git rev-parse HEAD^{tree} >expected &&
+
+	git merge-tree -X ours side1 side4 >actual &&
+
+	test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
 	# Mis-spell with single "s" instead of double "s"
 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v5] merge-tree: add -X strategy option
  2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
@ 2023-09-16  8:38         ` 唐宇奕
  2023-09-18  9:53         ` Phillip Wood
  2023-09-24  2:23         ` [PATCH v6] " Izzy via GitGitGadget
  2 siblings, 0 replies; 27+ messages in thread
From: 唐宇奕 @ 2023-09-16  8:38 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Elijah Newren, Jeff King

Thank you for your advice! I've uploaded new patch.

On Sat, Sep 16, 2023 at 4:37 PM Izzy via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: Tang Yuyi <winglovet@gmail.com>
>
> Add merge strategy option to produce more customizable merge result such
> as automatically resolving conflicts.
>
> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---
>     merge-tree: add -X strategy option
>
>     Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v5
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v5
> Pull-Request: https://github.com/gitgitgadget/git/pull/1565
>
> Range-diff vs v4:
>
>  1:  d2d8fcc2e9b ! 1:  28d4282e0d8 merge-tree: add -X strategy option
>      @@ Commit message
>
>        ## builtin/merge-tree.c ##
>       @@
>      + #include "quote.h"
>        #include "tree.h"
>        #include "config.h"
>      ++#include "strvec.h"
>
>      -+static const char **xopts;
>      -+static size_t xopts_nr, xopts_alloc;
>        static int line_termination = '\n';
>
>      - struct merge_list {
>       @@ builtin/merge-tree.c: struct merge_tree_options {
>         int show_messages;
>         int name_only;
>      @@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
>
>         opt.branch1 = branch1;
>       @@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
>      -  return !result.clean; /* result.clean < 0 handled above */
>      - }
>      -
>      -+static int option_parse_x(const struct option *opt,
>      -+                   const char *arg, int unset)
>      -+{
>      -+ if (unset)
>      -+         return 0;
>      -+
>      -+ ALLOC_GROW(xopts, xopts_nr + 1, xopts_alloc);
>      -+ xopts[xopts_nr++] = xstrdup(arg);
>      -+ return 0;
>      -+}
>      -+
>        int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>        {
>         struct merge_tree_options o = { .show_messages = -1 };
>      ++ struct strvec xopts = STRVEC_INIT;
>      +  int expected_remaining_argc;
>      +  int original_argc;
>      +  const char *merge_base = NULL;
>       @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
>      -+         OPT_CALLBACK('X', "strategy-option", &xopts,
>      -+                 N_("option=value"),
>      -+                 N_("option for selected merge strategy"),
>      -+                 option_parse_x),
>      ++         OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
>      ++                 N_("option for selected merge strategy")),
>                 OPT_END()
>         };
>
>      @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
>      -+ for (int x = 0; x < xopts_nr; x++)
>      -+         if (parse_merge_opt(&o.merge_options, xopts[x]))
>      -+                 die(_("unknown strategy option: -X%s"), xopts[x]);
>      ++ for (int x = 0; x < xopts.nr; x++)
>      ++         if (parse_merge_opt(&o.merge_options, xopts.v[x]))
>      ++                 die(_("unknown strategy option: -X%s"), xopts.v[x]);
>       +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>      @@ t/t4301-merge-tree-write-tree.sh: test_expect_success 'Content merge and a few c
>       + git merge --abort &&
>       +
>       + git merge -X ours side4 &&
>      -+ git rev-parse HEAD^{tree} > expected &&
>      ++ git rev-parse HEAD^{tree} >expected &&
>       +
>      -+    git merge-tree -X ours side1 side4 > actual &&
>      ++ git merge-tree -X ours side1 side4 >actual &&
>       +
>       + test_cmp expected actual
>       +'
>
>
>  builtin/merge-tree.c             | 11 +++++++++++
>  t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
>  2 files changed, 34 insertions(+)
>
> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..97d0fe6c952 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
> @@ -18,6 +18,7 @@
>  #include "quote.h"
>  #include "tree.h"
>  #include "config.h"
> +#include "strvec.h"
>
>  static int line_termination = '\n';
>
> @@ -414,6 +415,7 @@ struct merge_tree_options {
>         int show_messages;
>         int name_only;
>         int use_stdin;
> +       struct merge_options merge_options;
>  };
>
>  static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +441,8 @@ static int real_merge(struct merge_tree_options *o,
>
>         init_merge_options(&opt, the_repository);
>
> +       opt.recursive_variant = o->merge_options.recursive_variant;
> +
>         opt.show_rename_progress = 0;
>
>         opt.branch1 = branch1;
> @@ -513,6 +517,7 @@ static int real_merge(struct merge_tree_options *o,
>  int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>  {
>         struct merge_tree_options o = { .show_messages = -1 };
> +       struct strvec xopts = STRVEC_INIT;
>         int expected_remaining_argc;
>         int original_argc;
>         const char *merge_base = NULL;
> @@ -548,6 +553,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>                            &merge_base,
>                            N_("commit"),
>                            N_("specify a merge-base for the merge")),
> +               OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
> +                       N_("option for selected merge strategy")),
>                 OPT_END()
>         };
>
> @@ -556,6 +563,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>         argc = parse_options(argc, argv, prefix, mt_options,
>                              merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
>
> +       for (int x = 0; x < xopts.nr; x++)
> +               if (parse_merge_opt(&o.merge_options, xopts.v[x]))
> +                       die(_("unknown strategy option: -X%s"), xopts.v[x]);
> +
>         /* Handle --stdin */
>         if (o.use_stdin) {
>                 struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..b2c8a43fce3 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>         git branch side1 &&
>         git branch side2 &&
>         git branch side3 &&
> +       git branch side4 &&
>
>         git checkout side1 &&
>         test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>         test_tick &&
>         git commit -m rename-numbers &&
>
> +       git checkout side4 &&
> +       test_write_lines 0 1 2 3 4 5 >numbers &&
> +       echo yo >greeting &&
> +       git add numbers greeting &&
> +       test_tick &&
> +       git commit -m other-content-modifications &&
> +
>         git switch --orphan unrelated &&
>         >something-else &&
>         git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>         test_cmp expect actual
>  '
>
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +       git checkout side1^0 &&
> +
> +       # make sure merge conflict exists
> +       test_must_fail git merge side4 &&
> +       git merge --abort &&
> +
> +       git merge -X ours side4 &&
> +       git rev-parse HEAD^{tree} >expected &&
> +
> +       git merge-tree -X ours side1 side4 >actual &&
> +
> +       test_cmp expected actual
> +'
> +
>  test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>         # Mis-spell with single "s" instead of double "s"
>         test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
>
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
> --
> gitgitgadget

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v5] merge-tree: add -X strategy option
  2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
  2023-09-16  8:38         ` 唐宇奕
@ 2023-09-18  9:53         ` Phillip Wood
  2023-09-18 16:08           ` Junio C Hamano
  2023-09-24  2:23         ` [PATCH v6] " Izzy via GitGitGadget
  2 siblings, 1 reply; 27+ messages in thread
From: Phillip Wood @ 2023-09-18  9:53 UTC (permalink / raw)
  To: Izzy via GitGitGadget, git; +Cc: Elijah Newren, Jeff King, Izzy

On 16/09/2023 09:37, Izzy via GitGitGadget wrote:
> From: Tang Yuyi <winglovet@gmail.com>
> 
> Add merge strategy option to produce more customizable merge result such
> as automatically resolving conflicts.

I think adding a merge strategy option to merge-tree is a good idea, but 
have you tested this with anything apart from -Xours or -Xtheirs? It 
looks to me like those are the only two that this patch supports. If you 
look at parse_merge_opt() in merge-recursive.c you will see that there 
are many other options. In order to support all the merge options I 
think this patch needs a bit of refactoring.

> diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
> index 0de42aecf4b..97d0fe6c952 100644
> --- a/builtin/merge-tree.c
> +++ b/builtin/merge-tree.c
>   static int real_merge(struct merge_tree_options *o,
> @@ -439,6 +441,8 @@ static int real_merge(struct merge_tree_options *o,
>   
>   	init_merge_options(&opt, the_repository);
>   
> +	opt.recursive_variant = o->merge_options.recursive_variant;
> +

Rather that copying across individual members I think you should 
initialize o->merge_options properly in cmd_merge_tree() by calling 
init_merge_options() and then use o->merge_options instead of "opt" in 
this function. That way all the strategy options will be supported.

>   	opt.show_rename_progress = 0;
>   
>   	opt.branch1 = branch1;
> @@ -513,6 +517,7 @@ static int real_merge(struct merge_tree_options *o,
>   int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>   {
>   	struct merge_tree_options o = { .show_messages = -1 };
> +	struct strvec xopts = STRVEC_INIT;
>   	int expected_remaining_argc;
>   	int original_argc;
>   	const char *merge_base = NULL;
> @@ -548,6 +553,8 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
>   			   &merge_base,
>   			   N_("commit"),
>   			   N_("specify a merge-base for the merge")),
> +		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
> +			N_("option for selected merge strategy")),
>   		OPT_END()
>   	};
>   
> @@ -556,6 +563,10 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)

You should add

	init_merge_options(&o.merge_options);

here to ensure it is properly initialized.

>   	argc = parse_options(argc, argv, prefix, mt_options,
>   			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);

This is the right place to call parse_merge_opt() but I think we should 
first check that the user has requested a real merge rather than a 
trivial merge.

	if (xopts.nr && o.mode == MODE_TRIVIAL)
		die(_("--trivial-merge is incompatible with all other options"));

Otherwise if the user passes in invalid strategy option to a trivial 
merge they'll get an error about an invalid strategy option rather than 
being told --strategy-option is not supported with --trivial-merge.

Ideally there would be a preparatory patch that moves the switch 
statement that is below the "if(o.use_stdin)" block up to this point so 
we'd always have set o.mode before checking if it is a trivial merge. (I 
think you'd to change the code slightly when it is moved to add a check 
for o.use_stdin)

Best Wishes

Phillip

> +	for (int x = 0; x < xopts.nr; x++)
> +		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
> +			die(_("unknown strategy option: -X%s"), xopts.v[x]);
> +
>   	/* Handle --stdin */
>   	if (o.use_stdin) {
>   		struct strbuf buf = STRBUF_INIT;
> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 250f721795b..b2c8a43fce3 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -22,6 +22,7 @@ test_expect_success setup '
>   	git branch side1 &&
>   	git branch side2 &&
>   	git branch side3 &&
> +	git branch side4 &&
>   
>   	git checkout side1 &&
>   	test_write_lines 1 2 3 4 5 6 >numbers &&
> @@ -46,6 +47,13 @@ test_expect_success setup '
>   	test_tick &&
>   	git commit -m rename-numbers &&
>   
> +	git checkout side4 &&
> +	test_write_lines 0 1 2 3 4 5 >numbers &&
> +	echo yo >greeting &&
> +	git add numbers greeting &&
> +	test_tick &&
> +	git commit -m other-content-modifications &&
> +
>   	git switch --orphan unrelated &&
>   	>something-else &&
>   	git add something-else &&
> @@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
>   	test_cmp expect actual
>   '
>   
> +test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
> +	git checkout side1^0 &&
> +
> +	# make sure merge conflict exists
> +	test_must_fail git merge side4 &&
> +	git merge --abort &&
> +
> +	git merge -X ours side4 &&
> +	git rev-parse HEAD^{tree} >expected &&
> +
> +	git merge-tree -X ours side1 side4 >actual &&
> +
> +	test_cmp expected actual
> +'
> +
>   test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
>   	# Mis-spell with single "s" instead of double "s"
>   	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&
> 
> base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb


^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v5] merge-tree: add -X strategy option
  2023-09-18  9:53         ` Phillip Wood
@ 2023-09-18 16:08           ` Junio C Hamano
  0 siblings, 0 replies; 27+ messages in thread
From: Junio C Hamano @ 2023-09-18 16:08 UTC (permalink / raw)
  To: Phillip Wood; +Cc: Izzy via GitGitGadget, git, Elijah Newren, Jeff King, Izzy

Phillip Wood <phillip.wood123@gmail.com> writes:

> ...
> This is the right place to call parse_merge_opt() but I think we
> should first check that the user has requested a real merge rather
> than a trivial merge.
>
> 	if (xopts.nr && o.mode == MODE_TRIVIAL)
> 		die(_("--trivial-merge is incompatible with all other options"));
>
> Otherwise if the user passes in invalid strategy option to a trivial
> merge they'll get an error about an invalid strategy option rather
> than being told --strategy-option is not supported with
> --trivial-merge.

I presume that another issue with not having that compatibility
checking with "--trivial" would be when the user passes a valid
strategy option and it would be silently ignored.

> Ideally there would be a preparatory patch that moves the switch
> statement that is below the "if(o.use_stdin)" block up to this point
> so we'd always have set o.mode before checking if it is a trivial
> merge. (I think you'd to change the code slightly when it is moved to
> add a check for o.use_stdin)

That sounds very good.

Thanks for a good "stepping back a bit" review.  Highly appreciated.

^ permalink raw reply	[flat|nested] 27+ messages in thread

* [PATCH v6] merge-tree: add -X strategy option
  2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
  2023-09-16  8:38         ` 唐宇奕
  2023-09-18  9:53         ` Phillip Wood
@ 2023-09-24  2:23         ` Izzy via GitGitGadget
  2023-09-24  2:26           ` 唐宇奕
  2023-10-09  9:58           ` Phillip Wood
  2 siblings, 2 replies; 27+ messages in thread
From: Izzy via GitGitGadget @ 2023-09-24  2:23 UTC (permalink / raw)
  To: git; +Cc: Elijah Newren, Jeff King, Phillip Wood, Izzy, Tang Yuyi

From: Tang Yuyi <winglovet@gmail.com>

Add merge strategy option to produce more customizable merge result such
as automatically resolving conflicts.

Signed-off-by: Tang Yuyi <winglovet@gmail.com>
---
    merge-tree: add -X strategy option
    
    Change-Id: I16be592262d13cebcff8726eb043f7ecdb313b76

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1565%2FWingT%2Fmerge_tree_allow_strategy_option-v6
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1565/WingT/merge_tree_allow_strategy_option-v6
Pull-Request: https://github.com/gitgitgadget/git/pull/1565

Range-diff vs v5:

 1:  28d4282e0d8 ! 1:  6a3dd8aeb13 merge-tree: add -X strategy option
     @@ builtin/merge-tree.c: struct merge_tree_options {
       
       static int real_merge(struct merge_tree_options *o,
      @@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
     + {
     + 	struct commit *parent1, *parent2;
     + 	struct commit_list *merge_bases = NULL;
     +-	struct merge_options opt;
     ++	struct merge_options opt = o->merge_options;
     + 	struct merge_result result = { 0 };
     + 	int show_messages = o->show_messages;
       
     - 	init_merge_options(&opt, the_repository);
     +@@ builtin/merge-tree.c: static int real_merge(struct merge_tree_options *o,
     + 		help_unknown_ref(branch2, "merge-tree",
     + 				 _("not something we can merge"));
       
     -+	opt.recursive_variant = o->merge_options.recursive_variant;
     -+
     +-	init_merge_options(&opt, the_repository);
     +-
       	opt.show_rename_progress = 0;
       
       	opt.branch1 = branch1;
     @@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char
       		OPT_END()
       	};
       
     -@@ builtin/merge-tree.c: int cmd_merge_tree(int argc, const char **argv, const char *prefix)
     ++	/* Init merge options */
     ++	init_merge_options(&o.merge_options, the_repository);
     ++
     + 	/* Parse arguments */
     + 	original_argc = argc - 1; /* ignoring argv[0] */
       	argc = parse_options(argc, argv, prefix, mt_options,
       			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
       
     ++	if (xopts.nr && o.mode == MODE_TRIVIAL)
     ++		die(_("--trivial-merge is incompatible with all other options"));
      +	for (int x = 0; x < xopts.nr; x++)
      +		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
      +			die(_("unknown strategy option: -X%s"), xopts.v[x]);


 builtin/merge-tree.c             | 18 +++++++++++++++---
 t/t4301-merge-tree-write-tree.sh | 23 +++++++++++++++++++++++
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 0de42aecf4b..7024b5ce2e4 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -18,6 +18,7 @@
 #include "quote.h"
 #include "tree.h"
 #include "config.h"
+#include "strvec.h"
 
 static int line_termination = '\n';
 
@@ -414,6 +415,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
+	struct merge_options merge_options;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -423,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
 {
 	struct commit *parent1, *parent2;
 	struct commit_list *merge_bases = NULL;
-	struct merge_options opt;
+	struct merge_options opt = o->merge_options;
 	struct merge_result result = { 0 };
 	int show_messages = o->show_messages;
 
@@ -437,8 +439,6 @@ static int real_merge(struct merge_tree_options *o,
 		help_unknown_ref(branch2, "merge-tree",
 				 _("not something we can merge"));
 
-	init_merge_options(&opt, the_repository);
-
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
@@ -513,6 +513,7 @@ static int real_merge(struct merge_tree_options *o,
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
 	struct merge_tree_options o = { .show_messages = -1 };
+	struct strvec xopts = STRVEC_INIT;
 	int expected_remaining_argc;
 	int original_argc;
 	const char *merge_base = NULL;
@@ -548,14 +549,25 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
+		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
+			N_("option for selected merge strategy")),
 		OPT_END()
 	};
 
+	/* Init merge options */
+	init_merge_options(&o.merge_options, the_repository);
+
 	/* Parse arguments */
 	original_argc = argc - 1; /* ignoring argv[0] */
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
+	if (xopts.nr && o.mode == MODE_TRIVIAL)
+		die(_("--trivial-merge is incompatible with all other options"));
+	for (int x = 0; x < xopts.nr; x++)
+		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
+			die(_("unknown strategy option: -X%s"), xopts.v[x]);
+
 	/* Handle --stdin */
 	if (o.use_stdin) {
 		struct strbuf buf = STRBUF_INIT;
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 250f721795b..b2c8a43fce3 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -22,6 +22,7 @@ test_expect_success setup '
 	git branch side1 &&
 	git branch side2 &&
 	git branch side3 &&
+	git branch side4 &&
 
 	git checkout side1 &&
 	test_write_lines 1 2 3 4 5 6 >numbers &&
@@ -46,6 +47,13 @@ test_expect_success setup '
 	test_tick &&
 	git commit -m rename-numbers &&
 
+	git checkout side4 &&
+	test_write_lines 0 1 2 3 4 5 >numbers &&
+	echo yo >greeting &&
+	git add numbers greeting &&
+	test_tick &&
+	git commit -m other-content-modifications &&
+
 	git switch --orphan unrelated &&
 	>something-else &&
 	git add something-else &&
@@ -97,6 +105,21 @@ test_expect_success 'Content merge and a few conflicts' '
 	test_cmp expect actual
 '
 
+test_expect_success 'Auto resolve conflicts by "ours" strategy option' '
+	git checkout side1^0 &&
+
+	# make sure merge conflict exists
+	test_must_fail git merge side4 &&
+	git merge --abort &&
+
+	git merge -X ours side4 &&
+	git rev-parse HEAD^{tree} >expected &&
+
+	git merge-tree -X ours side1 side4 >actual &&
+
+	test_cmp expected actual
+'
+
 test_expect_success 'Barf on misspelled option, with exit code other than 0 or 1' '
 	# Mis-spell with single "s" instead of double "s"
 	test_expect_code 129 git merge-tree --write-tree --mesages FOOBAR side1 side2 2>expect &&

base-commit: ac83bc5054c2ac489166072334b4147ce6d0fccb
-- 
gitgitgadget

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-09-24  2:23         ` [PATCH v6] " Izzy via GitGitGadget
@ 2023-09-24  2:26           ` 唐宇奕
  2023-10-09  9:58           ` Phillip Wood
  1 sibling, 0 replies; 27+ messages in thread
From: 唐宇奕 @ 2023-09-24  2:26 UTC (permalink / raw)
  To: Izzy via GitGitGadget; +Cc: git, Elijah Newren, Jeff King, Phillip Wood

Thanks for your advice! I've uploaded a new patch to support more
strategy options and the parse option issue.

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-09-24  2:23         ` [PATCH v6] " Izzy via GitGitGadget
  2023-09-24  2:26           ` 唐宇奕
@ 2023-10-09  9:58           ` Phillip Wood
  2023-10-09 15:53             ` Jeff King
  1 sibling, 1 reply; 27+ messages in thread
From: Phillip Wood @ 2023-10-09  9:58 UTC (permalink / raw)
  To: Izzy via GitGitGadget, git; +Cc: Elijah Newren, Jeff King, Izzy

On 24/09/2023 03:23, Izzy via GitGitGadget wrote:

Thanks for updating the patch, sorry it has taken me a while to look at 
this.

> From: Tang Yuyi <winglovet@gmail.com>
> 
> Add merge strategy option to produce more customizable merge result such
> as automatically resolving conflicts.
> 
> Signed-off-by: Tang Yuyi <winglovet@gmail.com>
> ---

>   static int real_merge(struct merge_tree_options *o,
> @@ -423,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
>   {
>   	struct commit *parent1, *parent2;
>   	struct commit_list *merge_bases = NULL;
> -	struct merge_options opt;
> +	struct merge_options opt = o->merge_options;

Copying struct merge_options by value here is unusual in our code base. 
I don't think it introduces a bug (there is no function to free the 
resources allocated in struct merge_options so we do not end up freeing 
them twice for example) but it would be clearer that it was safe if you did

	struct merge_options *opt = &o->merge_options;

and updated the code to reflect that opt is now a pointer or just 
replaced all uses of "opt" with "o->merge_options"

> +	if (xopts.nr && o.mode == MODE_TRIVIAL)
> +		die(_("--trivial-merge is incompatible with all other options"));

This is good, thanks for adding it.

> +	for (int x = 0; x < xopts.nr; x++)

This is not worth a re-roll on its own but as xopts.nr is a size_t we 
should declare x to be the same type rather than an int.

The tests are pretty minimal, ideally we would check that "-X" works 
with "--stdin", that it is rejected by a trivial merge and that one of 
the other strategy options works.

Best Wishes

Phillip


^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-09  9:58           ` Phillip Wood
@ 2023-10-09 15:53             ` Jeff King
  2023-10-09 17:10               ` Junio C Hamano
  0 siblings, 1 reply; 27+ messages in thread
From: Jeff King @ 2023-10-09 15:53 UTC (permalink / raw)
  To: phillip.wood; +Cc: Izzy via GitGitGadget, git, Elijah Newren, Izzy

On Mon, Oct 09, 2023 at 10:58:07AM +0100, Phillip Wood wrote:

> > @@ -423,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
> >   {
> >   	struct commit *parent1, *parent2;
> >   	struct commit_list *merge_bases = NULL;
> > -	struct merge_options opt;
> > +	struct merge_options opt = o->merge_options;
> 
> Copying struct merge_options by value here is unusual in our code base. I
> don't think it introduces a bug (there is no function to free the resources
> allocated in struct merge_options so we do not end up freeing them twice for
> example) but it would be clearer that it was safe if you did
> 
> 	struct merge_options *opt = &o->merge_options;
> 
> and updated the code to reflect that opt is now a pointer or just replaced
> all uses of "opt" with "o->merge_options"

I agree that struct-copying is an unusual pattern, and we'd potentially
run into problems with duplication. But I think it is even trickier than
that here. We also go on to actually _modify_ opt in this function,
assigning to various members (both directly, and I think the merge code
itself will write to opt->priv).

So if we use a pointer (rather than struct assignment), those changes
will persist in the merge_options struct that was passed in. Which is
also weird.

Between the two, I think using a pointer is probably the least-weird.
This real_merge() function is only called once, and is a static-local
helper for cmd_merge_tree(). So the two functions work as a single unit,
and munging "opt" is not a big deal.

-Peff

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-09 15:53             ` Jeff King
@ 2023-10-09 17:10               ` Junio C Hamano
  2023-10-09 18:52                 ` Jeff King
  0 siblings, 1 reply; 27+ messages in thread
From: Junio C Hamano @ 2023-10-09 17:10 UTC (permalink / raw)
  To: Jeff King; +Cc: phillip.wood, Izzy via GitGitGadget, git, Elijah Newren, Izzy

Jeff King <peff@peff.net> writes:

> I agree that struct-copying is an unusual pattern, and we'd potentially
> run into problems with duplication. But I think it is even trickier than
> that here. We also go on to actually _modify_ opt in this function,
> assigning to various members (both directly, and I think the merge code
> itself will write to opt->priv).
>
> So if we use a pointer (rather than struct assignment), those changes
> will persist in the merge_options struct that was passed in. Which is
> also weird.
>
> Between the two, I think using a pointer is probably the least-weird.
> This real_merge() function is only called once, and is a static-local
> helper for cmd_merge_tree(). So the two functions work as a single unit,
> and munging "opt" is not a big deal.

It is called once per --stdin input to perform many merges in a row.
The most obvious "structure to pointer to structure" conversion
below seems to break an assertion (which is not very surprising, as
it happens inside that --stdin loop), so I am tempted to revert the
whole thing for now.

Thanks.


git: merge-ort.c:5110: merge_incore_recursive: Assertion `opt->ancestor == NULL' failed.
./test-lib.sh: line 1067: 738791 Done                    printf "c1 c3\nc2 -- c1 c3\nc2 c3"
     738792 Aborted                 | git -C repo merge-tree --stdin > actual


 builtin/merge-tree.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git c/builtin/merge-tree.c w/builtin/merge-tree.c
index 7024b5ce2e..1cb1fba2de 100644
--- c/builtin/merge-tree.c
+++ w/builtin/merge-tree.c
@@ -425,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
 {
 	struct commit *parent1, *parent2;
 	struct commit_list *merge_bases = NULL;
-	struct merge_options opt = o->merge_options;
+	struct merge_options *opt = &o->merge_options;
 	struct merge_result result = { 0 };
 	int show_messages = o->show_messages;
 
@@ -439,10 +439,10 @@ static int real_merge(struct merge_tree_options *o,
 		help_unknown_ref(branch2, "merge-tree",
 				 _("not something we can merge"));
 
-	opt.show_rename_progress = 0;
+	opt->show_rename_progress = 0;
 
-	opt.branch1 = branch1;
-	opt.branch2 = branch2;
+	opt->branch1 = branch1;
+	opt->branch2 = branch2;
 
 	if (merge_base) {
 		struct commit *base_commit;
@@ -452,11 +452,11 @@ static int real_merge(struct merge_tree_options *o,
 		if (!base_commit)
 			die(_("could not lookup commit '%s'"), merge_base);
 
-		opt.ancestor = merge_base;
+		opt->ancestor = merge_base;
 		base_tree = repo_get_commit_tree(the_repository, base_commit);
 		parent1_tree = repo_get_commit_tree(the_repository, parent1);
 		parent2_tree = repo_get_commit_tree(the_repository, parent2);
-		merge_incore_nonrecursive(&opt, base_tree, parent1_tree, parent2_tree, &result);
+		merge_incore_nonrecursive(opt, base_tree, parent1_tree, parent2_tree, &result);
 	} else {
 		/*
 		 * Get the merge bases, in reverse order; see comment above
@@ -467,7 +467,7 @@ static int real_merge(struct merge_tree_options *o,
 		if (!merge_bases && !o->allow_unrelated_histories)
 			die(_("refusing to merge unrelated histories"));
 		merge_bases = reverse_commit_list(merge_bases);
-		merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result);
+		merge_incore_recursive(opt, merge_bases, parent1, parent2, &result);
 	}
 
 	if (result.clean < 0)
@@ -501,12 +501,12 @@ static int real_merge(struct merge_tree_options *o,
 	}
 	if (show_messages) {
 		putchar(line_termination);
-		merge_display_update_messages(&opt, line_termination == '\0',
+		merge_display_update_messages(opt, line_termination == '\0',
 					      &result);
 	}
 	if (o->use_stdin)
 		putchar(line_termination);
-	merge_finalize(&opt, &result);
+	merge_finalize(opt, &result);
 	return !result.clean; /* result.clean < 0 handled above */
 }
 


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-09 17:10               ` Junio C Hamano
@ 2023-10-09 18:52                 ` Jeff King
  2023-10-11 19:38                   ` Junio C Hamano
  0 siblings, 1 reply; 27+ messages in thread
From: Jeff King @ 2023-10-09 18:52 UTC (permalink / raw)
  To: Junio C Hamano
  Cc: phillip.wood, Izzy via GitGitGadget, git, Elijah Newren, Izzy

On Mon, Oct 09, 2023 at 10:10:28AM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > I agree that struct-copying is an unusual pattern, and we'd potentially
> > run into problems with duplication. But I think it is even trickier than
> > that here. We also go on to actually _modify_ opt in this function,
> > assigning to various members (both directly, and I think the merge code
> > itself will write to opt->priv).
> >
> > So if we use a pointer (rather than struct assignment), those changes
> > will persist in the merge_options struct that was passed in. Which is
> > also weird.
> >
> > Between the two, I think using a pointer is probably the least-weird.
> > This real_merge() function is only called once, and is a static-local
> > helper for cmd_merge_tree(). So the two functions work as a single unit,
> > and munging "opt" is not a big deal.
> 
> It is called once per --stdin input to perform many merges in a row.
> The most obvious "structure to pointer to structure" conversion
> below seems to break an assertion (which is not very surprising, as
> it happens inside that --stdin loop), so I am tempted to revert the
> whole thing for now.

Oops, I totally missed the loop around the call to real_merge(). So
yeah, I think this is rather tricky.

Before Izzy's patch, real_merge() always makes its own fresh
merge_options. After, we have a template merge_options that we copy, but
we are assuming that a shallow struct copy is OK (probably true, but an
anti-pattern that may bite us later).  If we add Phillip's suggestion on
top, then we do not copy at all, and end up reusing the same options
struct (which is definitely wrong).

I don't think there are any bugs with the state at the current tip of
ty/merge-tree-strategy-options, but if we want to make it safer, I think
we have two options:

  - delay the conversion of the "xopts" list into merge_options until we
    initialize it in real_merge(). This avoids breaking abstraction
    boundaries, but does mean that the sanity-checking of the options
    happens a little later (but not much in practice).

  - provide a copy_merge_options() function, which makes this kind of
    "set up a template and then copy it" pattern official. It can be a
    struct assignment for now, but it at least alerts anybody adding new
    options to the notion that a deep copy might be required.

Option 1 looks something like this (a lot of the hunks are just
reverting the tip of that branch, so squashed in it would be even
smaller):

diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 7024b5ce2e..f9dbbdb867 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -415,7 +415,7 @@ struct merge_tree_options {
 	int show_messages;
 	int name_only;
 	int use_stdin;
-	struct merge_options merge_options;
+	struct strvec xopts;
 };
 
 static int real_merge(struct merge_tree_options *o,
@@ -425,7 +425,7 @@ static int real_merge(struct merge_tree_options *o,
 {
 	struct commit *parent1, *parent2;
 	struct commit_list *merge_bases = NULL;
-	struct merge_options opt = o->merge_options;
+	struct merge_options opt;
 	struct merge_result result = { 0 };
 	int show_messages = o->show_messages;
 
@@ -439,11 +439,17 @@ static int real_merge(struct merge_tree_options *o,
 		help_unknown_ref(branch2, "merge-tree",
 				 _("not something we can merge"));
 
+	init_merge_options(&opt, the_repository);
+
 	opt.show_rename_progress = 0;
 
 	opt.branch1 = branch1;
 	opt.branch2 = branch2;
 
+	for (size_t x = 0; x < o->xopts.nr; x++)
+		if (parse_merge_opt(&opt, o->xopts.v[x]))
+			die(_("unknown strategy option: -X%s"), o->xopts.v[x]);
+
 	if (merge_base) {
 		struct commit *base_commit;
 		struct tree *base_tree, *parent1_tree, *parent2_tree;
@@ -512,8 +518,7 @@ static int real_merge(struct merge_tree_options *o,
 
 int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 {
-	struct merge_tree_options o = { .show_messages = -1 };
-	struct strvec xopts = STRVEC_INIT;
+	struct merge_tree_options o = { .show_messages = -1,.xopts = STRVEC_INIT };
 	int expected_remaining_argc;
 	int original_argc;
 	const char *merge_base = NULL;
@@ -549,24 +554,18 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			   &merge_base,
 			   N_("commit"),
 			   N_("specify a merge-base for the merge")),
-		OPT_STRVEC('X', "strategy-option", &xopts, N_("option=value"),
+		OPT_STRVEC('X', "strategy-option", &o.xopts, N_("option=value"),
 			N_("option for selected merge strategy")),
 		OPT_END()
 	};
 
-	/* Init merge options */
-	init_merge_options(&o.merge_options, the_repository);
-
 	/* Parse arguments */
 	original_argc = argc - 1; /* ignoring argv[0] */
 	argc = parse_options(argc, argv, prefix, mt_options,
 			     merge_tree_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
-	if (xopts.nr && o.mode == MODE_TRIVIAL)
+	if (o.xopts.nr && o.mode == MODE_TRIVIAL)
 		die(_("--trivial-merge is incompatible with all other options"));
-	for (int x = 0; x < xopts.nr; x++)
-		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
-			die(_("unknown strategy option: -X%s"), xopts.v[x]);
 
 	/* Handle --stdin */
 	if (o.use_stdin) {

^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-09 18:52                 ` Jeff King
@ 2023-10-11 19:38                   ` Junio C Hamano
  2023-10-11 21:43                     ` Jeff King
  0 siblings, 1 reply; 27+ messages in thread
From: Junio C Hamano @ 2023-10-11 19:38 UTC (permalink / raw)
  To: Jeff King; +Cc: phillip.wood, Izzy via GitGitGadget, git, Elijah Newren, Izzy

Jeff King <peff@peff.net> writes:

> Oops, I totally missed the loop around the call to real_merge(). So
> yeah, I think this is rather tricky.
> ...
> I don't think there are any bugs with the state at the current tip of
> ty/merge-tree-strategy-options, but if we want to make it safer, I think
> we have two options:
>
>   - delay the conversion of the "xopts" list into merge_options until we
>     initialize it in real_merge(). This avoids breaking abstraction
>     boundaries, but does mean that the sanity-checking of the options
>     happens a little later (but not much in practice).
>
>   - provide a copy_merge_options() function, which makes this kind of
>     "set up a template and then copy it" pattern official. It can be a
>     struct assignment for now, but it at least alerts anybody adding new
>     options to the notion that a deep copy might be required.
>
> Option 1 looks something like this (a lot of the hunks are just
> reverting the tip of that branch, so squashed in it would be even
> smaller):

If we have no plan and intention to extend "merge-tree" even more in
the future, then option 1 would be the approach with least patch
noise, and as your "something like this" shows, it is a nice and
clean solution.  I very much like it.

But as the renovated "merge-tree" is a relatively young thing in our
toolbox, I suspect that more and more work may want to go into it.
And the other "official copy_merge_options()" approach would be a
more healthy solution in the longer run, I would think.  If we were
to go that route, we should also give an interface to free the
resources held by the copy.

It is not that much code on top of the commit that is already queued
in 'next', I suspect.  Perhaps something like this?

 builtin/merge-tree.c |  4 +++-
 merge-recursive.c    | 16 ++++++++++++++++
 merge-recursive.h    |  3 +++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git c/builtin/merge-tree.c w/builtin/merge-tree.c
index 7024b5ce2e..a35e0452d6 100644
--- c/builtin/merge-tree.c
+++ w/builtin/merge-tree.c
@@ -425,10 +425,11 @@ static int real_merge(struct merge_tree_options *o,
 {
 	struct commit *parent1, *parent2;
 	struct commit_list *merge_bases = NULL;
-	struct merge_options opt = o->merge_options;
 	struct merge_result result = { 0 };
 	int show_messages = o->show_messages;
+	struct merge_options opt;
 
+	copy_merge_options(&opt, &o->merge_options);
 	parent1 = get_merge_parent(branch1);
 	if (!parent1)
 		help_unknown_ref(branch1, "merge-tree",
@@ -507,6 +508,7 @@ static int real_merge(struct merge_tree_options *o,
 	if (o->use_stdin)
 		putchar(line_termination);
 	merge_finalize(&opt, &result);
+	clear_merge_options(&opt);
 	return !result.clean; /* result.clean < 0 handled above */
 }
 
diff --git c/merge-recursive.c w/merge-recursive.c
index 0d7e57e2df..e3beb0801b 100644
--- c/merge-recursive.c
+++ w/merge-recursive.c
@@ -3912,6 +3912,22 @@ void init_merge_options(struct merge_options *opt,
 		opt->buffer_output = 0;
 }
 
+/*
+ * For now, members of merge_options do not need deep copying, but
+ * it may change in the future, in which case we would need to update
+ * this, and also make a matching change to clear_merge_options() to
+ * release the resources held by a copied instance.
+ */
+void copy_merge_options(struct merge_options *dst, struct merge_options *src)
+{
+	*dst = *src;
+}
+
+void clear_merge_options(struct merge_options *opt UNUSED)
+{
+	; /* no-op as our copy is shallow right now */
+}
+
 int parse_merge_opt(struct merge_options *opt, const char *s)
 {
 	const char *arg;
diff --git c/merge-recursive.h w/merge-recursive.h
index b88000e3c2..3d3b3e3c29 100644
--- c/merge-recursive.h
+++ w/merge-recursive.h
@@ -55,6 +55,9 @@ struct merge_options {
 
 void init_merge_options(struct merge_options *opt, struct repository *repo);
 
+void copy_merge_options(struct merge_options *dst, struct merge_options *src);
+void clear_merge_options(struct merge_options *opt);
+
 /* parse the option in s and update the relevant field of opt */
 int parse_merge_opt(struct merge_options *opt, const char *s);
 


^ permalink raw reply related	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-11 19:38                   ` Junio C Hamano
@ 2023-10-11 21:43                     ` Jeff King
  2023-10-11 22:19                       ` Junio C Hamano
  0 siblings, 1 reply; 27+ messages in thread
From: Jeff King @ 2023-10-11 21:43 UTC (permalink / raw)
  To: Junio C Hamano
  Cc: phillip.wood, Izzy via GitGitGadget, git, Elijah Newren, Izzy

On Wed, Oct 11, 2023 at 12:38:03PM -0700, Junio C Hamano wrote:

> If we have no plan and intention to extend "merge-tree" even more in
> the future, then option 1 would be the approach with least patch
> noise, and as your "something like this" shows, it is a nice and
> clean solution.  I very much like it.
> 
> But as the renovated "merge-tree" is a relatively young thing in our
> toolbox, I suspect that more and more work may want to go into it.
> And the other "official copy_merge_options()" approach would be a
> more healthy solution in the longer run, I would think.  If we were
> to go that route, we should also give an interface to free the
> resources held by the copy.

I am happy with either, as they both resolve the "merge-tree knows
intimate details about merge_options" issue. The patch I showed would
require manually passing more details down to real_merge(), which is I
guess what you are getting at with the "more work may want to go into
it".

> It is not that much code on top of the commit that is already queued
> in 'next', I suspect.  Perhaps something like this?

This looks OK, though...

> +void clear_merge_options(struct merge_options *opt UNUSED)
> +{
> +	; /* no-op as our copy is shallow right now */
> +}

Clearing is generally not just about copies, but any use of the struct.
so this invites the question of whether the original non-copy struct
should have a call to clear_merge_options() in cmd_merge_tree(). And
ditto for every other user.

I do not mind adding such calls, but of course we know that they are
currently noops (and we don't have any particular plan to change that).

-Peff

^ permalink raw reply	[flat|nested] 27+ messages in thread

* Re: [PATCH v6] merge-tree: add -X strategy option
  2023-10-11 21:43                     ` Jeff King
@ 2023-10-11 22:19                       ` Junio C Hamano
  0 siblings, 0 replies; 27+ messages in thread
From: Junio C Hamano @ 2023-10-11 22:19 UTC (permalink / raw)
  To: Jeff King; +Cc: phillip.wood, Izzy via GitGitGadget, git, Elijah Newren, Izzy

Jeff King <peff@peff.net> writes:

> I am happy with either, as they both resolve the "merge-tree knows
> intimate details about merge_options" issue. The patch I showed would
> require manually passing more details down to real_merge(), which is I
> guess what you are getting at with the "more work may want to go into
> it".

I was alluding more about teaching "merge-tree" various optional
behaviour merge_options represents.  In today's patch it may be
-X<options>, who knows what tomorrow's patch wants to bring
"merge-tree" to feature-parity with "merge".  And the first approach
would mean we would add xopts today to the struct, but we will be
required passing more details as we add other things.

>> It is not that much code on top of the commit that is already queued
>> in 'next', I suspect.  Perhaps something like this?
>
> This looks OK, though...
>
>> +void clear_merge_options(struct merge_options *opt UNUSED)
>> +{
>> +	; /* no-op as our copy is shallow right now */
>> +}
>
> Clearing is generally not just about copies, but any use of the struct.
> so this invites the question of whether the original non-copy struct
> should have a call to clear_merge_options() in cmd_merge_tree(). And
> ditto for every other user.

Yes, once we start leaking, somebody hopefully notice the lack of a
call to this on the original/template copy and add one.  Until then...

^ permalink raw reply	[flat|nested] 27+ messages in thread

end of thread, other threads:[~2023-10-11 22:19 UTC | newest]

Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-08-05 14:24 [PATCH] merge-tree: add -X strategy option Izzy via GitGitGadget
2023-08-07  2:10 ` Junio C Hamano
2023-08-12  5:33 ` [PATCH v2] " Izzy via GitGitGadget
2023-08-12  5:41   ` 唐宇奕
2023-09-03  1:31     ` 唐宇奕
2023-09-12 15:03   ` Elijah Newren
2023-09-16  2:14   ` [PATCH v3] " Izzy via GitGitGadget
2023-09-16  2:26     ` 唐宇奕
2023-09-16  3:21       ` Elijah Newren
2023-09-16  3:16     ` Elijah Newren
2023-09-16  3:47     ` [PATCH v4] " Izzy via GitGitGadget
2023-09-16  3:55       ` Elijah Newren
2023-09-16  4:04       ` 唐宇奕
2023-09-16  6:11       ` Jeff King
2023-09-16  8:37       ` [PATCH v5] " Izzy via GitGitGadget
2023-09-16  8:38         ` 唐宇奕
2023-09-18  9:53         ` Phillip Wood
2023-09-18 16:08           ` Junio C Hamano
2023-09-24  2:23         ` [PATCH v6] " Izzy via GitGitGadget
2023-09-24  2:26           ` 唐宇奕
2023-10-09  9:58           ` Phillip Wood
2023-10-09 15:53             ` Jeff King
2023-10-09 17:10               ` Junio C Hamano
2023-10-09 18:52                 ` Jeff King
2023-10-11 19:38                   ` Junio C Hamano
2023-10-11 21:43                     ` Jeff King
2023-10-11 22:19                       ` Junio C Hamano

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