[PATCH 0/5] Better error messages for checkout and merge.

[PATCH 0/5] Better error messages for checkout and merge.

[Matthieu Moy]

This is a resurection of an old patch serie by Diane Gasselin:

http://thread.gmane.org/gmane.comp.version-control.git/149173/focus=149186

In short, when you have several untracked files that conflict with a
merge or checkout, Git currently reports just the first. After this
patch serie, it reports things like:

error: Your local changes to the following files would be overwritten by checkout:
	rep/two
	rep/one
Please, commit your changes or stash them before you can switch branches.

most of the job is done by "unpack_trees: group error messages by type",
but this needed a bit of preparation to be implementable cleanly.

Compared to previous version, there are many small cleanups, and:

* unpack_trees_options was a struct, it's now an array. This makes the
  code much cleaner whenever one tries to do clever things with it.
  That's patch "Turn unpack_trees_options.msgs into an array + enum".

* A message was previously a type + an action ("removed" or
  "overwritten"). The type now encompasses the action. This duplicates
  a few lines in the declaration of the error messages, but again
  makes the rest of the code much simpler. That's patch
  "merge-recursive: distinguish "removed" and "overwritten" messages"

* The info on whether traverse_trees should stop at the first error
  was stored in info->data, with a very fragile cast to
  (unpack_trees_options *). I added one more field in the info
  structure to get rid of this cast.

Diane Gasselin (2):
  merge-recursive: porcelain messages for checkout
  t7609: test merge and checkout error messages

Matthieu Moy (3):
  Turn unpack_trees_options.msgs into an array + enum
  merge-recursive: distinguish "removed" and "overwritten" messages
  unpack_trees: group error messages by type

 Documentation/technical/api-tree-walking.txt |    2 +
 builtin/checkout.c                           |    3 +-
 builtin/merge.c                              |    3 +-
 merge-recursive.c                            |   62 +++++++----
 merge-recursive.h                            |    7 +-
 t/t3030-merge-recursive.sh                   |    2 +-
 t/t3400-rebase.sh                            |    3 +-
 t/t3404-rebase-interactive.sh                |    3 +-
 t/t7609-merge-co-error-msgs.sh               |  125 ++++++++++++++++++++++
 tree-walk.c                                  |   11 ++-
 tree-walk.h                                  |    1 +
 unpack-trees.c                               |  148 ++++++++++++++++++++------
 unpack-trees.h                               |   34 ++++--
 13 files changed, 332 insertions(+), 72 deletions(-)
 create mode 100755 t/t7609-merge-co-error-msgs.sh

-- 
1.7.2.1.52.g95e25.dirty

[PATCH 1/5] Turn unpack_trees_options.msgs into an array + enum

[Matthieu Moy]

The list of error messages was introduced as a structure, but an array
indexed over an enum is more flexible, since it allows one to store a
type of error message (index in the array) in a variable.

This change needs to rename would_lose_untracked ->
would_lose_untracked_file to avoid a clash with the function
would_lose_untracked in merge-recursive.c.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 builtin/checkout.c |    2 +-
 builtin/merge.c    |    2 +-
 merge-recursive.c  |   29 +++++++++++------------------
 merge-recursive.h  |    4 ++--
 unpack-trees.c     |   16 ++++++++--------
 unpack-trees.h     |   19 ++++++++++---------
 6 files changed, 33 insertions(+), 39 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 1994be9..8854aab 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -373,7 +373,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.src_index = &the_index;
 		topts.dst_index = &the_index;
 
-		topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
+		topts.msgs[not_uptodate_file] = "You have local changes to '%s'; cannot switch branches.";
 
 		refresh_cache(REFRESH_QUIET);
 
diff --git a/builtin/merge.c b/builtin/merge.c
index 37ce4f5..115a288 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,7 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
-	opts.msgs = get_porcelain_error_msgs();
+	set_porcelain_error_msgs(opts.msgs);
 
 	trees[nr_trees] = parse_tree_indirect(head);
 	if (!trees[nr_trees++])
diff --git a/merge-recursive.c b/merge-recursive.c
index fb6aa4a..755f530 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -185,7 +185,7 @@ static int git_merge_trees(int index_only,
 	opts.fn = threeway_merge;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
-	opts.msgs = get_porcelain_error_msgs();
+	set_porcelain_error_msgs(opts.msgs);
 
 	init_tree_desc_from_tree(t+0, common);
 	init_tree_desc_from_tree(t+1, head);
@@ -1178,26 +1178,19 @@ static int process_entry(struct merge_options *o,
 	return clean_merge;
 }
 
-struct unpack_trees_error_msgs get_porcelain_error_msgs(void)
+void set_porcelain_error_msgs(const char **msgs)
 {
-	struct unpack_trees_error_msgs msgs = {
-		/* would_overwrite */
-		"Your local changes to '%s' would be overwritten by merge.  Aborting.",
-		/* not_uptodate_file */
-		"Your local changes to '%s' would be overwritten by merge.  Aborting.",
-		/* not_uptodate_dir */
-		"Updating '%s' would lose untracked files in it.  Aborting.",
-		/* would_lose_untracked */
-		"Untracked working tree file '%s' would be %s by merge.  Aborting",
-		/* bind_overlap -- will not happen here */
-		NULL,
-	};
-	if (advice_commit_before_merge) {
-		msgs.would_overwrite = msgs.not_uptodate_file =
+	if (advice_commit_before_merge)
+		msgs[would_overwrite] = msgs[not_uptodate_file] =
 			"Your local changes to '%s' would be overwritten by merge.  Aborting.\n"
 			"Please, commit your changes or stash them before you can merge.";
-	}
-	return msgs;
+	else
+		msgs[would_overwrite] = msgs[not_uptodate_file] =
+			"Your local changes to '%s' would be overwritten by merge.  Aborting.";
+	msgs[not_uptodate_dir] =
+		"Updating '%s' would lose untracked files in it.  Aborting.";
+	msgs[would_lose_untracked_file] =
+		"Untracked working tree file '%s' would be %s by merge.  Aborting";
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/merge-recursive.h b/merge-recursive.h
index b831293..8412db8 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -23,8 +23,8 @@ struct merge_options {
 	struct string_list current_directory_set;
 };
 
-/* Return a list of user-friendly error messages to be used by merge */
-struct unpack_trees_error_msgs get_porcelain_error_msgs(void);
+/* Sets the list of user-friendly error messages to be used by merge */
+void set_porcelain_error_msgs(const char **msgs);
 
 /* merge_trees() but with recursive ancestor consolidation */
 int merge_recursive(struct merge_options *o,
diff --git a/unpack-trees.c b/unpack-trees.c
index 8cf0da3..538f228 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -17,7 +17,7 @@
  * explain why it does not allow switching between branches when you have
  * local changes, for example.
  */
-static struct unpack_trees_error_msgs unpack_plumbing_errors = {
+const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* would_overwrite */
 	"Entry '%s' would be overwritten by merge. Cannot merge.",
 
@@ -27,7 +27,7 @@ static struct unpack_trees_error_msgs unpack_plumbing_errors = {
 	/* not_uptodate_dir */
 	"Updating '%s' would lose untracked files in it",
 
-	/* would_lose_untracked */
+	/* would_lose_untracked_file */
 	"Untracked working tree file '%s' would be %s by merge.",
 
 	/* bind_overlap */
@@ -40,10 +40,10 @@ static struct unpack_trees_error_msgs unpack_plumbing_errors = {
 	"Working tree file '%s' would be %s by sparse checkout update.",
 };
 
-#define ERRORMSG(o,fld) \
-	( ((o) && (o)->msgs.fld) \
-	? ((o)->msgs.fld) \
-	: (unpack_plumbing_errors.fld) )
+#define ERRORMSG(o,type) \
+	( ((o) && (o)->msgs[(type)]) \
+	  ? ((o)->msgs[(type)])      \
+	  : (unpack_plumbing_errors[(type)]) )
 
 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
 	unsigned int set, unsigned int clear)
@@ -1068,7 +1068,7 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, would_lose_untracked), ce->name, action);
+			error(ERRORMSG(o, would_lose_untracked_file), ce->name, action);
 	}
 	return 0;
 }
@@ -1077,7 +1077,7 @@ static int verify_absent(struct cache_entry *ce, const char *action,
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
+	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked_file));
 }
 
 static int verify_absent_sparse(struct cache_entry *ce, const char *action,
diff --git a/unpack-trees.h b/unpack-trees.h
index ef70eab..3a6d2b4 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -9,14 +9,15 @@ struct exclude_list;
 typedef int (*merge_fn_t)(struct cache_entry **src,
 		struct unpack_trees_options *options);
 
-struct unpack_trees_error_msgs {
-	const char *would_overwrite;
-	const char *not_uptodate_file;
-	const char *not_uptodate_dir;
-	const char *would_lose_untracked;
-	const char *bind_overlap;
-	const char *sparse_not_uptodate_file;
-	const char *would_lose_orphaned;
+enum unpack_trees_error_types {
+	would_overwrite = 0,
+	not_uptodate_file,
+	not_uptodate_dir,
+	would_lose_untracked_file,
+	bind_overlap,
+	sparse_not_uptodate_file,
+	would_lose_orphaned,
+	NB_UNPACK_TREES_ERROR_TYPES
 };
 
 struct unpack_trees_options {
@@ -38,7 +39,7 @@ struct unpack_trees_options {
 	int cache_bottom;
 	struct dir_struct *dir;
 	merge_fn_t fn;
-	struct unpack_trees_error_msgs msgs;
+	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
 
 	int head_idx;
 	int merge_size;
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 2/5] merge-recursive: porcelain messages for checkout

[Matthieu Moy]

From: Diane Gasselin <diane.gasselin@ensimag.imag.fr>

A porcelain message was first added in checkout.c in the commit
8ccba008 (Junio C Hamano, Sat May 17 21:03:49 2008, unpack-trees:
allow Porcelain to give different error messages) to give better feedback
in the case of merge errors.

This patch adapts the porcelain messages for the case of checkout
instead. This way, when having a checkout error, "merge" no longer
appears in the error message.

While we're there, we add an advice in the case of
would_lose_untracked_file.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 builtin/checkout.c |    2 +-
 builtin/merge.c    |    2 +-
 merge-recursive.c  |   31 ++++++++++++++++++++++---------
 merge-recursive.h  |    7 +++++--
 4 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 8854aab..22bf47c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -373,7 +373,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.src_index = &the_index;
 		topts.dst_index = &the_index;
 
-		topts.msgs[not_uptodate_file] = "You have local changes to '%s'; cannot switch branches.";
+		set_porcelain_error_msgs(topts.msgs, "checkout");
 
 		refresh_cache(REFRESH_QUIET);
 
diff --git a/builtin/merge.c b/builtin/merge.c
index 115a288..de5a0f6 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,7 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
-	set_porcelain_error_msgs(opts.msgs);
+	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	trees[nr_trees] = parse_tree_indirect(head);
 	if (!trees[nr_trees++])
diff --git a/merge-recursive.c b/merge-recursive.c
index 755f530..bd26497 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -185,7 +185,7 @@ static int git_merge_trees(int index_only,
 	opts.fn = threeway_merge;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
-	set_porcelain_error_msgs(opts.msgs);
+	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	init_tree_desc_from_tree(t+0, common);
 	init_tree_desc_from_tree(t+1, head);
@@ -1178,19 +1178,32 @@ static int process_entry(struct merge_options *o,
 	return clean_merge;
 }
 
-void set_porcelain_error_msgs(const char **msgs)
+void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 {
+	const char *msg;
+	char *tmp;
+	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
 	if (advice_commit_before_merge)
-		msgs[would_overwrite] = msgs[not_uptodate_file] =
-			"Your local changes to '%s' would be overwritten by merge.  Aborting.\n"
-			"Please, commit your changes or stash them before you can merge.";
+		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.\n"
+			"Please, commit your changes or stash them before you can %s.";
 	else
-		msgs[would_overwrite] = msgs[not_uptodate_file] =
-			"Your local changes to '%s' would be overwritten by merge.  Aborting.";
+		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+	sprintf(tmp, msg, cmd, cmd2);
+	msgs[would_overwrite] = tmp;
+	msgs[not_uptodate_file] = tmp;
+
 	msgs[not_uptodate_dir] =
 		"Updating '%s' would lose untracked files in it.  Aborting.";
-	msgs[would_lose_untracked_file] =
-		"Untracked working tree file '%s' would be %s by merge.  Aborting";
+
+	if (advice_commit_before_merge)
+		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting"
+			"Please move or remove them before you can %s.";
+	else
+		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+	sprintf(tmp, msg, cmd, cmd2);
+	msgs[would_lose_untracked_file] = tmp;
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/merge-recursive.h b/merge-recursive.h
index 8412db8..08f9850 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -23,8 +23,11 @@ struct merge_options {
 	struct string_list current_directory_set;
 };
 
-/* Sets the list of user-friendly error messages to be used by merge */
-void set_porcelain_error_msgs(const char **msgs);
+/*
+ * Sets the list of user-friendly error messages to be used by the
+ * command "cmd" (either merge or checkout)
+ */
+void set_porcelain_error_msgs(const char **msgs, const char *cmd);
 
 /* merge_trees() but with recursive ancestor consolidation */
 int merge_recursive(struct merge_options *o,
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 3/5] merge-recursive: distinguish "removed" and "overwritten" messages

[Matthieu Moy]

To limit the number of possible error messages, the error messages for
the case would_lose_untracked_file and would_lose_orphaned in
unpack_trees_options.msgs were handled with a single string,
parameterized by an action string ("overwritten" or "removed").

Instead, we consider them as two different cases, with unparameterized
string. This will make it easier to make separate lists sorted by error
types later.

Only the bind_overlap case still takes two %s parameters, but that's
unavoidable.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 merge-recursive.c |   13 ++++++----
 unpack-trees.c    |   64 ++++++++++++++++++++++++++++++++--------------------
 unpack-trees.h    |    6 +++-
 3 files changed, 51 insertions(+), 32 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index bd26497..8c1b189 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1197,13 +1197,16 @@ void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 		"Updating '%s' would lose untracked files in it.  Aborting.";
 
 	if (advice_commit_before_merge)
-		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting"
+		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting"
 			"Please move or remove them before you can %s.";
 	else
-		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting";
-	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
-	sprintf(tmp, msg, cmd, cmd2);
-	msgs[would_lose_untracked_file] = tmp;
+		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
+	sprintf(tmp, msg, "removed", cmd, cmd2);
+	msgs[would_lose_untracked_removed] = tmp;
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
+	sprintf(tmp, msg, "overwritten", cmd, cmd2);
+	msgs[would_lose_untracked_overwritten] = tmp;
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/unpack-trees.c b/unpack-trees.c
index 538f228..143f897 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -27,8 +27,11 @@ const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* not_uptodate_dir */
 	"Updating '%s' would lose untracked files in it",
 
-	/* would_lose_untracked_file */
-	"Untracked working tree file '%s' would be %s by merge.",
+	/* would_lose_untracked_overwritten */
+	"Untracked working tree file '%s' would be overwritten by merge.",
+
+	/* would_lose_untracked_removed */
+	"Untracked working tree file '%s' would be removed by merge.",
 
 	/* bind_overlap */
 	"Entry '%s' overlaps with '%s'.  Cannot bind.",
@@ -36,8 +39,11 @@ const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* sparse_not_uptodate_file */
 	"Entry '%s' not uptodate. Cannot update sparse checkout.",
 
-	/* would_lose_orphaned */
-	"Working tree file '%s' would be %s by sparse checkout update.",
+	/* would_lose_orphaned_overwritten */
+	"Working tree file '%s' would be overwritten by sparse checkout update.",
+
+	/* would_lose_orphaned_removed */
+	"Working tree file '%s' would be removed by sparse checkout update.",
 };
 
 #define ERRORMSG(o,type) \
@@ -132,7 +138,7 @@ static int check_updates(struct unpack_trees_options *o)
 }
 
 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
-static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
+static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
 
 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
 {
@@ -175,7 +181,7 @@ static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_opt
 		ce->ce_flags |= CE_WT_REMOVE;
 	}
 	if (was_skip_worktree && !ce_skip_worktree(ce)) {
-		if (verify_absent_sparse(ce, "overwritten", o))
+		if (verify_absent_sparse(ce, would_lose_untracked_overwritten, o))
 			return -1;
 		ce->ce_flags |= CE_UPDATE;
 	}
@@ -860,7 +866,7 @@ static int same(struct cache_entry *a, struct cache_entry *b)
  */
 static int verify_uptodate_1(struct cache_entry *ce,
 				   struct unpack_trees_options *o,
-				   const char *error_msg)
+				   enum unpack_trees_error_types error_type)
 {
 	struct stat st;
 
@@ -885,7 +891,7 @@ static int verify_uptodate_1(struct cache_entry *ce,
 	if (errno == ENOENT)
 		return 0;
 	return o->gently ? -1 :
-		error(error_msg, ce->name);
+		error(ERRORMSG(o, error_type), ce->name);
 }
 
 static int verify_uptodate(struct cache_entry *ce,
@@ -893,13 +899,13 @@ static int verify_uptodate(struct cache_entry *ce,
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
+	return verify_uptodate_1(ce, o, not_uptodate_file);
 }
 
 static int verify_uptodate_sparse(struct cache_entry *ce,
 				  struct unpack_trees_options *o)
 {
-	return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
+	return verify_uptodate_1(ce, o, sparse_not_uptodate_file);
 }
 
 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
@@ -915,13 +921,15 @@ static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_optio
  * Currently, git does not checkout subprojects during a superproject
  * checkout, so it is not going to overwrite anything.
  */
-static int verify_clean_submodule(struct cache_entry *ce, const char *action,
+static int verify_clean_submodule(struct cache_entry *ce,
+				      enum unpack_trees_error_types error_type,
 				      struct unpack_trees_options *o)
 {
 	return 0;
 }
 
-static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
+static int verify_clean_subdirectory(struct cache_entry *ce,
+				      enum unpack_trees_error_types error_type,
 				      struct unpack_trees_options *o)
 {
 	/*
@@ -942,7 +950,7 @@ static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
 		 */
 		if (!hashcmp(sha1, ce->sha1))
 			return 0;
-		return verify_clean_submodule(ce, action, o);
+		return verify_clean_submodule(ce, error_type, o);
 	}
 
 	/*
@@ -1011,9 +1019,9 @@ static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst,
  * We do not want to remove or overwrite a working tree file that
  * is not tracked, unless it is ignored.
  */
-static int verify_absent_1(struct cache_entry *ce, const char *action,
-				 struct unpack_trees_options *o,
-				 const char *error_msg)
+static int verify_absent_1(struct cache_entry *ce,
+				 enum unpack_trees_error_types error_type,
+				 struct unpack_trees_options *o)
 {
 	struct stat st;
 
@@ -1051,7 +1059,7 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 			 * files that are in "foo/" we would lose
 			 * them.
 			 */
-			if (verify_clean_subdirectory(ce, action, o) < 0)
+			if (verify_clean_subdirectory(ce, error_type, o) < 0)
 				return -1;
 			return 0;
 		}
@@ -1068,22 +1076,28 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, would_lose_untracked_file), ce->name, action);
+			error(ERRORMSG(o, error_type), ce->name);
 	}
 	return 0;
 }
-static int verify_absent(struct cache_entry *ce, const char *action,
+static int verify_absent(struct cache_entry *ce,
+			 enum unpack_trees_error_types error_type,
 			 struct unpack_trees_options *o)
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked_file));
+	return verify_absent_1(ce, error_type, o);
 }
 
-static int verify_absent_sparse(struct cache_entry *ce, const char *action,
+static int verify_absent_sparse(struct cache_entry *ce,
+			 enum unpack_trees_error_types error_type,
 			 struct unpack_trees_options *o)
 {
-	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
+	enum unpack_trees_error_types orphaned_error = error_type;
+	if (orphaned_error == would_lose_untracked_overwritten)
+		orphaned_error = would_lose_orphaned_overwritten;
+
+	return verify_absent_1(ce, orphaned_error, o);
 }
 
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
@@ -1092,7 +1106,7 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
 	int update = CE_UPDATE;
 
 	if (!old) {
-		if (verify_absent(merge, "overwritten", o))
+		if (verify_absent(merge, would_lose_untracked_overwritten, o))
 			return -1;
 		invalidate_ce_path(merge, o);
 	} else if (!(old->ce_flags & CE_CONFLICTED)) {
@@ -1130,7 +1144,7 @@ static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
 {
 	/* Did it exist in the index? */
 	if (!old) {
-		if (verify_absent(ce, "removed", o))
+		if (verify_absent(ce, would_lose_untracked_removed, o))
 			return -1;
 		return 0;
 	}
@@ -1279,7 +1293,7 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
 			if (index)
 				return deleted_entry(index, index, o);
 			if (ce && !head_deleted) {
-				if (verify_absent(ce, "removed", o))
+				if (verify_absent(ce, would_lose_untracked_removed, o))
 					return -1;
 			}
 			return 0;
diff --git a/unpack-trees.h b/unpack-trees.h
index 3a6d2b4..edda877 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -13,10 +13,12 @@ enum unpack_trees_error_types {
 	would_overwrite = 0,
 	not_uptodate_file,
 	not_uptodate_dir,
-	would_lose_untracked_file,
+	would_lose_untracked_overwritten,
+	would_lose_untracked_removed,
 	bind_overlap,
 	sparse_not_uptodate_file,
-	would_lose_orphaned,
+	would_lose_orphaned_overwritten,
+	would_lose_orphaned_removed,
 	NB_UNPACK_TREES_ERROR_TYPES
 };
 
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 4/5] unpack_trees: group error messages by type

[Matthieu Moy]

When an error is encountered, it calls add_rejected_file() which either
- directly displays the error message and stops if in plumbing mode
  (i.e. if show_all_errors is not initialized at 1)
- or stores it so that it will be displayed at the end with display_error_msgs(),

Storing the files by error type permits to have a list of files for
which there is the same error instead of having a serie of almost
identical errors.

As each bind_overlap error combines a file and an old file, a list cannot be
done, therefore, theses errors are not stored but directly displayed.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 Documentation/technical/api-tree-walking.txt |    2 +
 builtin/checkout.c                           |    1 +
 builtin/merge.c                              |    1 +
 merge-recursive.c                            |   25 ++++++--
 t/t3030-merge-recursive.sh                   |    2 +-
 t/t3400-rebase.sh                            |    3 +-
 t/t3404-rebase-interactive.sh                |    3 +-
 tree-walk.c                                  |   11 +++-
 tree-walk.h                                  |    1 +
 unpack-trees.c                               |   78 ++++++++++++++++++++++++-
 unpack-trees.h                               |   13 ++++-
 11 files changed, 123 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-tree-walking.txt b/Documentation/technical/api-tree-walking.txt
index 55b7286..14af37c 100644
--- a/Documentation/technical/api-tree-walking.txt
+++ b/Documentation/technical/api-tree-walking.txt
@@ -42,6 +42,8 @@ information.
 
 * `data` can be anything the `fn` callback would want to use.
 
+* `show_all_errors` tells whether to stop at the first error or not.
+
 Initializing
 ------------
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 22bf47c..894bb84 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -392,6 +392,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.dir = xcalloc(1, sizeof(*topts.dir));
 		topts.dir->flags |= DIR_SHOW_IGNORED;
 		topts.dir->exclude_per_dir = ".gitignore";
+		topts.show_all_errors = 1;
 		tree = parse_tree_indirect(old->commit ?
 					   old->commit->object.sha1 :
 					   (unsigned char *)EMPTY_TREE_SHA1_BIN);
diff --git a/builtin/merge.c b/builtin/merge.c
index de5a0f6..1bcf7fd 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,6 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
+	opts.show_all_errors = 1;
 	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	trees[nr_trees] = parse_tree_indirect(head);
diff --git a/merge-recursive.c b/merge-recursive.c
index 8c1b189..e292d6e 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1184,29 +1184,42 @@ void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 	char *tmp;
 	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
 	if (advice_commit_before_merge)
-		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.\n"
+		msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
 			"Please, commit your changes or stash them before you can %s.";
 	else
-		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.";
-	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+		msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
 	sprintf(tmp, msg, cmd, cmd2);
 	msgs[would_overwrite] = tmp;
 	msgs[not_uptodate_file] = tmp;
 
 	msgs[not_uptodate_dir] =
-		"Updating '%s' would lose untracked files in it.  Aborting.";
+		"Updating the following directories would lose untracked files in it:\n%s";
 
 	if (advice_commit_before_merge)
-		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting"
+		msg = "The following untracked working tree files would be %s by %s:\n%%s"
 			"Please move or remove them before you can %s.";
 	else
-		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting";
+		msg = "The following untracked working tree files would be %s by %s:\n%%s";
 	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
 	sprintf(tmp, msg, "removed", cmd, cmd2);
 	msgs[would_lose_untracked_removed] = tmp;
 	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
 	sprintf(tmp, msg, "overwritten", cmd, cmd2);
 	msgs[would_lose_untracked_overwritten] = tmp;
+
+	/*
+	 * Special case: bind_overlap refers to a pair of paths, we
+	 * cannot easily display it as a list.
+	 */
+	msgs[bind_overlap] = "Entry '%s' overlaps with '%s'.  Cannot bind.";
+
+	msgs[sparse_not_uptodate_file] =
+		"Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
+	msgs[would_lose_orphaned_overwritten] =
+		"The following Working tree files would be overwritten by sparse checkout update:\n%s";
+	msgs[would_lose_orphaned_removed] =
+		"The following Working tree files would be removed by sparse checkout update:\n%s";
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/t/t3030-merge-recursive.sh b/t/t3030-merge-recursive.sh
index d541544..efe2900 100755
--- a/t/t3030-merge-recursive.sh
+++ b/t/t3030-merge-recursive.sh
@@ -294,7 +294,7 @@ test_expect_success 'fail if the index has unresolved entries' '
 	grep "You have not concluded your merge" out &&
 	rm -f .git/MERGE_HEAD &&
 	test_must_fail git merge "$c5" 2> out &&
-	grep "Your local changes to .* would be overwritten by merge." out
+	grep "Your local changes to the following files would be overwritten by merge:" out
 '
 
 test_expect_success 'merge-recursive remove conflict' '
diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index d98c7b5..45ef282 100755
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -129,7 +129,8 @@ test_expect_success 'rebase a single mode change' '
 test_expect_success 'Show verbose error when HEAD could not be detached' '
      : > B &&
      test_must_fail git rebase topic 2> output.err > output.out &&
-     grep "Untracked working tree file .B. would be overwritten" output.err
+     grep "The following untracked working tree files would be overwritten by checkout:" output.err &&
+     grep B output.err
 '
 rm -f B
 
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9f03ce6..3af3f60 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -150,8 +150,9 @@ test_expect_success 'abort with error when new base cannot be checked out' '
 	git rm --cached file1 &&
 	git commit -m "remove file in base" &&
 	test_must_fail git rebase -i master > output 2>&1 &&
-	grep "Untracked working tree file .file1. would be overwritten" \
+	grep "The following untracked working tree files would be overwritten by checkout:" \
 		output &&
+	grep "file1" output &&
 	! test -d .git/rebase-merge &&
 	git reset --hard HEAD^
 '
diff --git a/tree-walk.c b/tree-walk.c
index 67a9a0c..a9bbf4e 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "tree-walk.h"
+#include "unpack-trees.h"
 #include "tree.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
@@ -310,6 +311,7 @@ static void free_extended_entry(struct tree_desc_x *t)
 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 {
 	int ret = 0;
+	int error = 0;
 	struct name_entry *entry = xmalloc(n*sizeof(*entry));
 	int i;
 	struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
@@ -377,8 +379,11 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 		if (!mask)
 			break;
 		ret = info->fn(n, mask, dirmask, entry, info);
-		if (ret < 0)
-			break;
+		if (ret < 0) {
+			error = ret;
+			if (!info->show_all_errors)
+				break;
+		}
 		mask &= ret;
 		ret = 0;
 		for (i = 0; i < n; i++)
@@ -389,7 +394,7 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 	for (i = 0; i < n; i++)
 		free_extended_entry(tx + i);
 	free(tx);
-	return ret;
+	return error;
 }
 
 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
diff --git a/tree-walk.h b/tree-walk.h
index 42110a4..88ea7e9 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -45,6 +45,7 @@ struct traverse_info {
 	unsigned long conflicts;
 	traverse_callback_t fn;
 	void *data;
+	int show_all_errors;
 };
 
 int get_tree_entry(const unsigned char *, const char *, unsigned char *, unsigned *);
diff --git a/unpack-trees.c b/unpack-trees.c
index 143f897..75249db 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -66,6 +66,73 @@ static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
 }
 
 /*
+ * add error messages on path <path>
+ * corresponding to the type <e> with the message <msg>
+ * indicating if it should be display in porcelain or not
+ */
+static int add_rejected_path(struct unpack_trees_options *o,
+			     enum unpack_trees_error_types e,
+			     const char *path)
+{
+	struct rejected_paths_list *newentry;
+	int porcelain = o && (o)->msgs[e];
+	/*
+	 * simply display the given error message if in plumbing mode
+	 */
+	if (!porcelain)
+		o->show_all_errors = 0;
+	if (!o->show_all_errors)
+		return error(ERRORMSG(o, e), path);
+
+	/*
+	 * Otherwise, insert in a list for future display by
+	 * display_error_msgs()
+	 */
+	newentry = xmalloc(sizeof(struct rejected_paths_list));
+	newentry->path = (char *)path;
+	newentry->next = o->unpack_rejects[e];
+	o->unpack_rejects[e] = newentry;
+	return -1;
+}
+
+/*
+ * free all the structures allocated for the error <e>
+ */
+static void free_rejected_paths(struct unpack_trees_options *o,
+				enum unpack_trees_error_types e)
+{
+	while (o->unpack_rejects[e]) {
+		struct rejected_paths_list *del = o->unpack_rejects[e];
+		o->unpack_rejects[e] = o->unpack_rejects[e]->next;
+		free(del);
+	}
+	free(o->unpack_rejects[e]);
+}
+
+/*
+ * display all the error messages stored in a nice way
+ */
+static void display_error_msgs(struct unpack_trees_options *o)
+{
+	int e;
+	int something_displayed = 0;
+	for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
+		if (o->unpack_rejects[e]) {
+			struct rejected_paths_list *rp;
+			struct strbuf path = STRBUF_INIT;
+			something_displayed = 1;
+			for (rp = o->unpack_rejects[e]; rp; rp = rp->next)
+				strbuf_addf(&path, "\t%s\n", rp->path);
+			error(ERRORMSG(o, e), path.buf);
+			strbuf_release(&path);
+			free_rejected_paths(o, e);
+		}
+	}
+	if (something_displayed)
+		printf("Aborting\n");
+}
+
+/*
  * Unlink the last component and schedule the leading directories for
  * removal, such that empty directories get removed.
  */
@@ -756,6 +823,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 		setup_traverse_info(&info, prefix);
 		info.fn = unpack_callback;
 		info.data = o;
+		info.show_all_errors = o->show_all_errors;
 
 		if (o->prefix) {
 			/*
@@ -835,6 +903,8 @@ done:
 	return ret;
 
 return_failed:
+	if (o->show_all_errors)
+		display_error_msgs(o);
 	mark_all_ce_unused(o->src_index);
 	ret = unpack_failed(o, NULL);
 	goto done;
@@ -844,7 +914,7 @@ return_failed:
 
 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
 {
-	return error(ERRORMSG(o, would_overwrite), ce->name);
+	return add_rejected_path(o, would_overwrite, ce->name);
 }
 
 static int same(struct cache_entry *a, struct cache_entry *b)
@@ -891,7 +961,7 @@ static int verify_uptodate_1(struct cache_entry *ce,
 	if (errno == ENOENT)
 		return 0;
 	return o->gently ? -1 :
-		error(ERRORMSG(o, error_type), ce->name);
+		add_rejected_path(o, error_type, ce->name);
 }
 
 static int verify_uptodate(struct cache_entry *ce,
@@ -994,7 +1064,7 @@ static int verify_clean_subdirectory(struct cache_entry *ce,
 	i = read_directory(&d, pathbuf, namelen+1, NULL);
 	if (i)
 		return o->gently ? -1 :
-			error(ERRORMSG(o, not_uptodate_dir), ce->name);
+			add_rejected_path(o, not_uptodate_dir, ce->name);
 	free(pathbuf);
 	return cnt;
 }
@@ -1076,7 +1146,7 @@ static int verify_absent_1(struct cache_entry *ce,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, error_type), ce->name);
+			add_rejected_path(o, error_type, ce->name);
 	}
 	return 0;
 }
diff --git a/unpack-trees.h b/unpack-trees.h
index edda877..785bc10 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -22,6 +22,11 @@ enum unpack_trees_error_types {
 	NB_UNPACK_TREES_ERROR_TYPES
 };
 
+struct rejected_paths_list {
+	char *path;
+	struct rejected_paths_list *next;
+};
+
 struct unpack_trees_options {
 	unsigned int reset,
 		     merge,
@@ -36,12 +41,18 @@ struct unpack_trees_options {
 		     diff_index_cached,
 		     debug_unpack,
 		     skip_sparse_checkout,
-		     gently;
+		     gently,
+		     show_all_errors;
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;
 	merge_fn_t fn;
 	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
+	/*
+	 * Store error messages in an array, each case
+	 * corresponding to a error message type
+	 */
+	struct rejected_paths_list *unpack_rejects[NB_UNPACK_TREES_ERROR_TYPES];
 
 	int head_idx;
 	int merge_size;
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 5/5] t7609: test merge and checkout error messages

[Matthieu Moy]

From: Diane Gasselin <diane.gasselin@ensimag.imag.fr>

Test porcelain and plumbing error messages for different types of errors
of merge and checkout.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 t/t7609-merge-co-error-msgs.sh |  125 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 125 insertions(+), 0 deletions(-)
 create mode 100755 t/t7609-merge-co-error-msgs.sh

diff --git a/t/t7609-merge-co-error-msgs.sh b/t/t7609-merge-co-error-msgs.sh
new file mode 100755
index 0000000..1a109b4
--- /dev/null
+++ b/t/t7609-merge-co-error-msgs.sh
@@ -0,0 +1,125 @@
+#!/bin/sh
+
+test_description='unpack-trees error messages'
+
+. ./test-lib.sh
+
+
+test_expect_success 'setup' '
+	echo one >one &&
+	git add one &&
+	git commit -a -m First &&
+
+	git checkout -b branch &&
+	echo two >two &&
+	echo three >three &&
+	echo four >four &&
+	echo five >five &&
+	git add two three four five &&
+	git commit -m Second &&
+
+	git checkout master &&
+	echo other >two &&
+	echo other >three &&
+	echo other >four &&
+	echo other >five
+'
+
+cat >expect <<\EOF
+error: The following untracked working tree files would be overwritten by merge:
+	two
+	three
+	four
+	five
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'untracked files overwritten by merge' '
+	test_must_fail git merge branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by merge:
+	two
+	three
+	four
+Please, commit your changes or stash them before you can merge.
+error: The following untracked working tree files would be overwritten by merge:
+	five
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'untracked files or local changes ovewritten by merge' '
+	git add two &&
+	git add three &&
+	git add four &&
+	test_must_fail git merge branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by checkout:
+	rep/two
+	rep/one
+Please, commit your changes or stash them before you can switch branches.
+EOF
+
+test_expect_success 'cannot switch branches because of local changes' '
+	git add five &&
+	mkdir rep &&
+	echo one >rep/one &&
+	echo two >rep/two &&
+	git add rep/one rep/two &&
+	git commit -m Fourth &&
+	git checkout master &&
+	echo uno >rep/one &&
+	echo dos >rep/two &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by checkout:
+	rep/two
+	rep/one
+Please, commit your changes or stash them before you can switch branches.
+EOF
+
+test_expect_success 'not uptodate file porcelain checkout error' '
+	git add rep/one rep/two &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Updating the following directories would lose untracked files in it:
+	rep2
+	rep
+
+EOF
+
+test_expect_success 'not_uptodate_dir porcelain checkout error' '
+	git init uptodate &&
+	cd uptodate &&
+	mkdir rep &&
+	mkdir rep2 &&
+	touch rep/foo &&
+	touch rep2/foo &&
+	git add rep/foo rep2/foo &&
+	git commit -m init &&
+	git checkout -b branch &&
+	git rm rep -r &&
+	git rm rep2 -r &&
+	>rep &&
+	>rep2 &&
+	git add rep rep2&&
+	git commit -m "added test as a file" &&
+	git checkout master &&
+	>rep/untracked-file &&
+	>rep2/untracked-file &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out ../expect
+'
+
+test_done
-- 
1.7.2.1.52.g95e25.dirty

Re: [PATCH 1/5] Turn unpack_trees_options.msgs into an array + enum

[Junio C Hamano]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> The list of error messages was introduced as a structure, but an array
> indexed over an enum is more flexible, since it allows one to store a
> type of error message (index in the array) in a variable.

Hmm, the only example of the advantage "enum used as array index" offers
that I can think of off the top of my head is that you can more easily
iterate over it.

> This change needs to rename would_lose_untracked ->
> would_lose_untracked_file to avoid a clash with the function
> would_lose_untracked in merge-recursive.c.

Yes, that shows one upside of "field names in a structure" has over
"enum used as array index".  We get a unique namespace.

If you are to change them to enum, I would actually suggest renaming them
a bit more to make them stand out.  Perhaps spell them all in caps,
perhaps have them share the same short prefix (UTEM_ - unpack trees error
messages), etc.

Having said all that, I am not against the main idea of this patch.

Re: [PATCH 2/5] merge-recursive: porcelain messages for checkout

[Junio C Hamano]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> +void set_porcelain_error_msgs(const char **msgs, const char *cmd)
>  {
> +	const char *msg;
> +	char *tmp;
> +	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";

This may have implications to the later i18n effort, but lets ignore it
for now.  I don't think it will be too bad.

Re: [PATCH 1/5] Turn unpack_trees_options.msgs into an array + enum

[Matthieu Moy]

Junio C Hamano <gitster@pobox.com> writes:

> Matthieu Moy <Matthieu.Moy@imag.fr> writes:
>
>> The list of error messages was introduced as a structure, but an array
>> indexed over an enum is more flexible, since it allows one to store a
>> type of error message (index in the array) in a variable.
>
> Hmm, the only example of the advantage "enum used as array index" offers
> that I can think of off the top of my head is that you can more easily
> iterate over it.

The portion of my message you cite give another: the ability to store
the index easily in a variable (or to pass it as argument to a
function). With a struct, you can easily pass field name to a macro,
but not to a function.

The other is that you can have multiple arrays indexed over the same
enum, which is what we do later: we'll have to manage an array of list
of rejected paths, with one list per error kind.

(we'll also have to iterate over this second array)

The previous version of the patch serie was using both a struct and an
enum + array, and I wanted to get rid of that.

> If you are to change them to enum, I would actually suggest renaming them
> a bit more to make them stand out.  Perhaps spell them all in caps,
> perhaps have them share the same short prefix (UTEM_ - unpack trees error
> messages), etc.

I'd say just "ERROR_*" (UTEM seems hard to read, and won't be used
often enough for people to remember it), but I'm fine with all caps +
prefix, yes. A quick grep shows this is how the rest of Git does.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/

Re: [PATCH 2/5] merge-recursive: porcelain messages for checkout

[Matthieu Moy]

Junio C Hamano <gitster@pobox.com> writes:

> Matthieu Moy <Matthieu.Moy@imag.fr> writes:
>
>> +void set_porcelain_error_msgs(const char **msgs, const char *cmd)
>>  {
>> +	const char *msg;
>> +	char *tmp;
>> +	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
>
> This may have implications to the later i18n effort, but lets ignore it
> for now.  I don't think it will be too bad.

Note that the ? : construct just allows factoring out two messages,
but one can easily distinguish all cases and give the complete error
message in the source (we don't care about performance/memory here,
it's a one-time thing).

So, yes, that's easily fixable later if it causes problems to i18n.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/

Re: [PATCH 2/5] merge-recursive: porcelain messages for checkout

[Ævar Arnfjörð Bjarmason]

On Mon, Aug 9, 2010 at 20:52, Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> wrote:
> Junio C Hamano <gitster@pobox.com> writes:
>
>> Matthieu Moy <Matthieu.Moy@imag.fr> writes:
>>
>>> +void set_porcelain_error_msgs(const char **msgs, const char *cmd)
>>>  {
>>> +    const char *msg;
>>> +    char *tmp;
>>> +    const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
>>
>> This may have implications to the later i18n effort, but lets ignore it
>> for now.  I don't think it will be too bad.
>
> Note that the ? : construct just allows factoring out two messages,
> but one can easily distinguish all cases and give the complete error
> message in the source (we don't care about performance/memory here,
> it's a one-time thing).
>
> So, yes, that's easily fixable later if it causes problems to i18n.

Yeah, this is a drop in the lego ocean that is Git's source
code. Don't worry about it, it can be fixed later.

You can stop reading at this point.

FWIW "lego" is the i18n term used for printf("messages %s assembled
like this", "that are"). E.g.:

    printf(_("It's a nice %s"), is_evening() ? _("evening") : _("day"));

Things like that will cause trouble for e.g. French where it's "C'est
un soirée formidable." or "C'est un jour formidable." (I hope I got
that right). You can move the %s around, but it's still hard to
translate stuff like that, especially as translation programs often
display strings independently.

It's better to have independent strings like _("It's a nice evening")
and _("It's a nice day") instead, even if it leads to duplication.

I'll be submitting a lot of patches to fix things like this once the
i18n series gets merged.

Have fun.

[PATCH 1/5 v2] Turn unpack_trees_options.msgs into an array + enum

[Matthieu Moy]

The list of error messages was introduced as a structure, but an array
indexed over an enum is more flexible, since it allows one to store a
type of error message (index in the array) in a variable.

This change needs to rename would_lose_untracked ->
would_lose_untracked_file to avoid a clash with the function
would_lose_untracked in merge-recursive.c.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> writes:

> Junio C Hamano <gitster@pobox.com> writes:
>
>> If you are to change them to enum, I would actually suggest renaming them
>> a bit more to make them stand out.  Perhaps spell them all in caps,
>> perhaps have them share the same short prefix (UTEM_ - unpack trees error
>> messages), etc.
>
> I'd say just "ERROR_*" (UTEM seems hard to read, and won't be used
> often enough for people to remember it), but I'm fine with all caps +
> prefix, yes. A quick grep shows this is how the rest of Git does.

So, here it is. BTW, git filter-branch rocks ;-).

Doing this change, I noticed a comment about "git checkout" overriding
only the "not_uptodate_file" case only, which I fixed, but there's no
other change compared to v1.

 builtin/checkout.c |    2 +-
 builtin/merge.c    |    2 +-
 merge-recursive.c  |   29 +++++++++++------------------
 merge-recursive.h  |    4 ++--
 unpack-trees.c     |   42 +++++++++++++++++++++---------------------
 unpack-trees.h     |   19 ++++++++++---------
 6 files changed, 46 insertions(+), 52 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 1994be9..7d1706e 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -373,7 +373,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.src_index = &the_index;
 		topts.dst_index = &the_index;
 
-		topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
+		topts.msgs[ERROR_NOT_UPTODATE_FILE] = "You have local changes to '%s'; cannot switch branches.";
 
 		refresh_cache(REFRESH_QUIET);
 
diff --git a/builtin/merge.c b/builtin/merge.c
index 37ce4f5..115a288 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,7 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
-	opts.msgs = get_porcelain_error_msgs();
+	set_porcelain_error_msgs(opts.msgs);
 
 	trees[nr_trees] = parse_tree_indirect(head);
 	if (!trees[nr_trees++])
diff --git a/merge-recursive.c b/merge-recursive.c
index fb6aa4a..d3bd963 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -185,7 +185,7 @@ static int git_merge_trees(int index_only,
 	opts.fn = threeway_merge;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
-	opts.msgs = get_porcelain_error_msgs();
+	set_porcelain_error_msgs(opts.msgs);
 
 	init_tree_desc_from_tree(t+0, common);
 	init_tree_desc_from_tree(t+1, head);
@@ -1178,26 +1178,19 @@ static int process_entry(struct merge_options *o,
 	return clean_merge;
 }
 
-struct unpack_trees_error_msgs get_porcelain_error_msgs(void)
+void set_porcelain_error_msgs(const char **msgs)
 {
-	struct unpack_trees_error_msgs msgs = {
-		/* would_overwrite */
-		"Your local changes to '%s' would be overwritten by merge.  Aborting.",
-		/* not_uptodate_file */
-		"Your local changes to '%s' would be overwritten by merge.  Aborting.",
-		/* not_uptodate_dir */
-		"Updating '%s' would lose untracked files in it.  Aborting.",
-		/* would_lose_untracked */
-		"Untracked working tree file '%s' would be %s by merge.  Aborting",
-		/* bind_overlap -- will not happen here */
-		NULL,
-	};
-	if (advice_commit_before_merge) {
-		msgs.would_overwrite = msgs.not_uptodate_file =
+	if (advice_commit_before_merge)
+		msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
 			"Your local changes to '%s' would be overwritten by merge.  Aborting.\n"
 			"Please, commit your changes or stash them before you can merge.";
-	}
-	return msgs;
+	else
+		msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
+			"Your local changes to '%s' would be overwritten by merge.  Aborting.";
+	msgs[ERROR_NOT_UPTODATE_DIR] =
+		"Updating '%s' would lose untracked files in it.  Aborting.";
+	msgs[ERROR_WOULD_LOSE_UNTRACKED] =
+		"Untracked working tree file '%s' would be %s by merge.  Aborting";
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/merge-recursive.h b/merge-recursive.h
index b831293..8412db8 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -23,8 +23,8 @@ struct merge_options {
 	struct string_list current_directory_set;
 };
 
-/* Return a list of user-friendly error messages to be used by merge */
-struct unpack_trees_error_msgs get_porcelain_error_msgs(void);
+/* Sets the list of user-friendly error messages to be used by merge */
+void set_porcelain_error_msgs(const char **msgs);
 
 /* merge_trees() but with recursive ancestor consolidation */
 int merge_recursive(struct merge_options *o,
diff --git a/unpack-trees.c b/unpack-trees.c
index 8cf0da3..304e59a 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -13,37 +13,37 @@
  * Error messages expected by scripts out of plumbing commands such as
  * read-tree.  Non-scripted Porcelain is not required to use these messages
  * and in fact are encouraged to reword them to better suit their particular
- * situation better.  See how "git checkout" replaces not_uptodate_file to
+ * situation better.  See how "git checkout" replaces ERROR_NOT_UPTODATE_FILE to
  * explain why it does not allow switching between branches when you have
  * local changes, for example.
  */
-static struct unpack_trees_error_msgs unpack_plumbing_errors = {
-	/* would_overwrite */
+const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
+	/* ERROR_WOULD_OVERWRITE */
 	"Entry '%s' would be overwritten by merge. Cannot merge.",
 
-	/* not_uptodate_file */
+	/* ERROR_NOT_UPTODATE_FILE */
 	"Entry '%s' not uptodate. Cannot merge.",
 
-	/* not_uptodate_dir */
+	/* ERROR_NOT_UPTODATE_DIR */
 	"Updating '%s' would lose untracked files in it",
 
-	/* would_lose_untracked */
+	/* ERROR_WOULD_LOSE_UNTRACKED */
 	"Untracked working tree file '%s' would be %s by merge.",
 
-	/* bind_overlap */
+	/* ERROR_BIND_OVERLAP */
 	"Entry '%s' overlaps with '%s'.  Cannot bind.",
 
-	/* sparse_not_uptodate_file */
+	/* ERROR_SPARSE_NOT_UPTODATE_FILE */
 	"Entry '%s' not uptodate. Cannot update sparse checkout.",
 
-	/* would_lose_orphaned */
+	/* ERROR_WOULD_LOSE_ORPHANED */
 	"Working tree file '%s' would be %s by sparse checkout update.",
 };
 
-#define ERRORMSG(o,fld) \
-	( ((o) && (o)->msgs.fld) \
-	? ((o)->msgs.fld) \
-	: (unpack_plumbing_errors.fld) )
+#define ERRORMSG(o,type) \
+	( ((o) && (o)->msgs[(type)]) \
+	  ? ((o)->msgs[(type)])      \
+	  : (unpack_plumbing_errors[(type)]) )
 
 static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
 	unsigned int set, unsigned int clear)
@@ -838,7 +838,7 @@ return_failed:
 
 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
 {
-	return error(ERRORMSG(o, would_overwrite), ce->name);
+	return error(ERRORMSG(o, ERROR_WOULD_OVERWRITE), ce->name);
 }
 
 static int same(struct cache_entry *a, struct cache_entry *b)
@@ -893,13 +893,13 @@ static int verify_uptodate(struct cache_entry *ce,
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_uptodate_1(ce, o, ERRORMSG(o, not_uptodate_file));
+	return verify_uptodate_1(ce, o, ERRORMSG(o, ERROR_NOT_UPTODATE_FILE));
 }
 
 static int verify_uptodate_sparse(struct cache_entry *ce,
 				  struct unpack_trees_options *o)
 {
-	return verify_uptodate_1(ce, o, ERRORMSG(o, sparse_not_uptodate_file));
+	return verify_uptodate_1(ce, o, ERRORMSG(o, ERROR_SPARSE_NOT_UPTODATE_FILE));
 }
 
 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
@@ -986,7 +986,7 @@ static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
 	i = read_directory(&d, pathbuf, namelen+1, NULL);
 	if (i)
 		return o->gently ? -1 :
-			error(ERRORMSG(o, not_uptodate_dir), ce->name);
+			error(ERRORMSG(o, ERROR_NOT_UPTODATE_DIR), ce->name);
 	free(pathbuf);
 	return cnt;
 }
@@ -1068,7 +1068,7 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, would_lose_untracked), ce->name, action);
+			error(ERRORMSG(o, ERROR_WOULD_LOSE_UNTRACKED), ce->name, action);
 	}
 	return 0;
 }
@@ -1077,13 +1077,13 @@ static int verify_absent(struct cache_entry *ce, const char *action,
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_untracked));
+	return verify_absent_1(ce, action, o, ERRORMSG(o, ERROR_WOULD_LOSE_UNTRACKED));
 }
 
 static int verify_absent_sparse(struct cache_entry *ce, const char *action,
 			 struct unpack_trees_options *o)
 {
-	return verify_absent_1(ce, action, o, ERRORMSG(o, would_lose_orphaned));
+	return verify_absent_1(ce, action, o, ERRORMSG(o, ERROR_WOULD_LOSE_ORPHANED));
 }
 
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
@@ -1412,7 +1412,7 @@ int bind_merge(struct cache_entry **src,
 			     o->merge_size);
 	if (a && old)
 		return o->gently ? -1 :
-			error(ERRORMSG(o, bind_overlap), a->name, old->name);
+			error(ERRORMSG(o, ERROR_BIND_OVERLAP), a->name, old->name);
 	if (!a)
 		return keep_entry(old, o);
 	else
diff --git a/unpack-trees.h b/unpack-trees.h
index ef70eab..09e2252 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -9,14 +9,15 @@ struct exclude_list;
 typedef int (*merge_fn_t)(struct cache_entry **src,
 		struct unpack_trees_options *options);
 
-struct unpack_trees_error_msgs {
-	const char *would_overwrite;
-	const char *not_uptodate_file;
-	const char *not_uptodate_dir;
-	const char *would_lose_untracked;
-	const char *bind_overlap;
-	const char *sparse_not_uptodate_file;
-	const char *would_lose_orphaned;
+enum unpack_trees_error_types {
+	ERROR_WOULD_OVERWRITE = 0,
+	ERROR_NOT_UPTODATE_FILE,
+	ERROR_NOT_UPTODATE_DIR,
+	ERROR_WOULD_LOSE_UNTRACKED,
+	ERROR_BIND_OVERLAP,
+	ERROR_SPARSE_NOT_UPTODATE_FILE,
+	ERROR_WOULD_LOSE_ORPHANED,
+	NB_UNPACK_TREES_ERROR_TYPES
 };
 
 struct unpack_trees_options {
@@ -38,7 +39,7 @@ struct unpack_trees_options {
 	int cache_bottom;
 	struct dir_struct *dir;
 	merge_fn_t fn;
-	struct unpack_trees_error_msgs msgs;
+	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
 
 	int head_idx;
 	int merge_size;
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 2/5 v2] merge-recursive: porcelain messages for checkout

[Matthieu Moy]

From: Diane Gasselin <diane.gasselin@ensimag.imag.fr>

A porcelain message was first added in checkout.c in the commit
8ccba008 (Junio C Hamano, Sat May 17 21:03:49 2008, unpack-trees:
allow Porcelain to give different error messages) to give better feedback
in the case of merge errors.

This patch adapts the porcelain messages for the case of checkout
instead. This way, when having a checkout error, "merge" no longer
appears in the error message.

While we're there, we add an advice in the case of
would_lose_untracked_file.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 builtin/checkout.c |    2 +-
 builtin/merge.c    |    2 +-
 merge-recursive.c  |   31 ++++++++++++++++++++++---------
 merge-recursive.h  |    7 +++++--
 unpack-trees.c     |    5 ++---
 5 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 7d1706e..22bf47c 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -373,7 +373,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.src_index = &the_index;
 		topts.dst_index = &the_index;
 
-		topts.msgs[ERROR_NOT_UPTODATE_FILE] = "You have local changes to '%s'; cannot switch branches.";
+		set_porcelain_error_msgs(topts.msgs, "checkout");
 
 		refresh_cache(REFRESH_QUIET);
 
diff --git a/builtin/merge.c b/builtin/merge.c
index 115a288..de5a0f6 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,7 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
-	set_porcelain_error_msgs(opts.msgs);
+	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	trees[nr_trees] = parse_tree_indirect(head);
 	if (!trees[nr_trees++])
diff --git a/merge-recursive.c b/merge-recursive.c
index d3bd963..b1e526b 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -185,7 +185,7 @@ static int git_merge_trees(int index_only,
 	opts.fn = threeway_merge;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
-	set_porcelain_error_msgs(opts.msgs);
+	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	init_tree_desc_from_tree(t+0, common);
 	init_tree_desc_from_tree(t+1, head);
@@ -1178,19 +1178,32 @@ static int process_entry(struct merge_options *o,
 	return clean_merge;
 }
 
-void set_porcelain_error_msgs(const char **msgs)
+void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 {
+	const char *msg;
+	char *tmp;
+	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
 	if (advice_commit_before_merge)
-		msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
-			"Your local changes to '%s' would be overwritten by merge.  Aborting.\n"
-			"Please, commit your changes or stash them before you can merge.";
+		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.\n"
+			"Please, commit your changes or stash them before you can %s.";
 	else
-		msgs[ERROR_WOULD_OVERWRITE] = msgs[ERROR_NOT_UPTODATE_FILE] =
-			"Your local changes to '%s' would be overwritten by merge.  Aborting.";
+		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+	sprintf(tmp, msg, cmd, cmd2);
+	msgs[ERROR_WOULD_OVERWRITE] = tmp;
+	msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
+
 	msgs[ERROR_NOT_UPTODATE_DIR] =
 		"Updating '%s' would lose untracked files in it.  Aborting.";
-	msgs[ERROR_WOULD_LOSE_UNTRACKED] =
-		"Untracked working tree file '%s' would be %s by merge.  Aborting";
+
+	if (advice_commit_before_merge)
+		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting"
+			"Please move or remove them before you can %s.";
+	else
+		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+	sprintf(tmp, msg, cmd, cmd2);
+	msgs[ERROR_WOULD_LOSE_UNTRACKED] = tmp;
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/merge-recursive.h b/merge-recursive.h
index 8412db8..08f9850 100644
--- a/merge-recursive.h
+++ b/merge-recursive.h
@@ -23,8 +23,11 @@ struct merge_options {
 	struct string_list current_directory_set;
 };
 
-/* Sets the list of user-friendly error messages to be used by merge */
-void set_porcelain_error_msgs(const char **msgs);
+/*
+ * Sets the list of user-friendly error messages to be used by the
+ * command "cmd" (either merge or checkout)
+ */
+void set_porcelain_error_msgs(const char **msgs, const char *cmd);
 
 /* merge_trees() but with recursive ancestor consolidation */
 int merge_recursive(struct merge_options *o,
diff --git a/unpack-trees.c b/unpack-trees.c
index 304e59a..e325831 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -13,9 +13,8 @@
  * Error messages expected by scripts out of plumbing commands such as
  * read-tree.  Non-scripted Porcelain is not required to use these messages
  * and in fact are encouraged to reword them to better suit their particular
- * situation better.  See how "git checkout" replaces ERROR_NOT_UPTODATE_FILE to
- * explain why it does not allow switching between branches when you have
- * local changes, for example.
+ * situation better.  See how "git checkout" and "git merge" replaces
+ * them using set_porcelain_error_msgs(), for example.
  */
 const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* ERROR_WOULD_OVERWRITE */
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 3/5 v2] merge-recursive: distinguish "removed" and "overwritten" messages

[Matthieu Moy]

To limit the number of possible error messages, the error messages for
the case would_lose_untracked_file and would_lose_orphaned in
unpack_trees_options.msgs were handled with a single string,
parameterized by an action string ("overwritten" or "removed").

Instead, we consider them as two different cases, with unparameterized
string. This will make it easier to make separate lists sorted by error
types later.

Only the bind_overlap case still takes two %s parameters, but that's
unavoidable.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 merge-recursive.c |   13 ++++++----
 unpack-trees.c    |   64 ++++++++++++++++++++++++++++++++--------------------
 unpack-trees.h    |    6 +++-
 3 files changed, 51 insertions(+), 32 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index b1e526b..697d948 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1197,13 +1197,16 @@ void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 		"Updating '%s' would lose untracked files in it.  Aborting.";
 
 	if (advice_commit_before_merge)
-		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting"
+		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting"
 			"Please move or remove them before you can %s.";
 	else
-		msg = "Untracked working tree file '%%s' would be %%s by %s.  Aborting";
-	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
-	sprintf(tmp, msg, cmd, cmd2);
-	msgs[ERROR_WOULD_LOSE_UNTRACKED] = tmp;
+		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
+	sprintf(tmp, msg, "removed", cmd, cmd2);
+	msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
+	sprintf(tmp, msg, "overwritten", cmd, cmd2);
+	msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/unpack-trees.c b/unpack-trees.c
index e325831..342f5ec 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -26,8 +26,11 @@ const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* ERROR_NOT_UPTODATE_DIR */
 	"Updating '%s' would lose untracked files in it",
 
-	/* ERROR_WOULD_LOSE_UNTRACKED */
-	"Untracked working tree file '%s' would be %s by merge.",
+	/* ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN */
+	"Untracked working tree file '%s' would be overwritten by merge.",
+
+	/* ERROR_WOULD_LOSE_UNTRACKED_REMOVED */
+	"Untracked working tree file '%s' would be removed by merge.",
 
 	/* ERROR_BIND_OVERLAP */
 	"Entry '%s' overlaps with '%s'.  Cannot bind.",
@@ -35,8 +38,11 @@ const char *unpack_plumbing_errors[NB_UNPACK_TREES_ERROR_TYPES] = {
 	/* ERROR_SPARSE_NOT_UPTODATE_FILE */
 	"Entry '%s' not uptodate. Cannot update sparse checkout.",
 
-	/* ERROR_WOULD_LOSE_ORPHANED */
-	"Working tree file '%s' would be %s by sparse checkout update.",
+	/* ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN */
+	"Working tree file '%s' would be overwritten by sparse checkout update.",
+
+	/* ERROR_WOULD_LOSE_ORPHANED_REMOVED */
+	"Working tree file '%s' would be removed by sparse checkout update.",
 };
 
 #define ERRORMSG(o,type) \
@@ -131,7 +137,7 @@ static int check_updates(struct unpack_trees_options *o)
 }
 
 static int verify_uptodate_sparse(struct cache_entry *ce, struct unpack_trees_options *o);
-static int verify_absent_sparse(struct cache_entry *ce, const char *action, struct unpack_trees_options *o);
+static int verify_absent_sparse(struct cache_entry *ce, enum unpack_trees_error_types, struct unpack_trees_options *o);
 
 static int will_have_skip_worktree(const struct cache_entry *ce, struct unpack_trees_options *o)
 {
@@ -174,7 +180,7 @@ static int apply_sparse_checkout(struct cache_entry *ce, struct unpack_trees_opt
 		ce->ce_flags |= CE_WT_REMOVE;
 	}
 	if (was_skip_worktree && !ce_skip_worktree(ce)) {
-		if (verify_absent_sparse(ce, "overwritten", o))
+		if (verify_absent_sparse(ce, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
 			return -1;
 		ce->ce_flags |= CE_UPDATE;
 	}
@@ -859,7 +865,7 @@ static int same(struct cache_entry *a, struct cache_entry *b)
  */
 static int verify_uptodate_1(struct cache_entry *ce,
 				   struct unpack_trees_options *o,
-				   const char *error_msg)
+				   enum unpack_trees_error_types error_type)
 {
 	struct stat st;
 
@@ -884,7 +890,7 @@ static int verify_uptodate_1(struct cache_entry *ce,
 	if (errno == ENOENT)
 		return 0;
 	return o->gently ? -1 :
-		error(error_msg, ce->name);
+		error(ERRORMSG(o, error_type), ce->name);
 }
 
 static int verify_uptodate(struct cache_entry *ce,
@@ -892,13 +898,13 @@ static int verify_uptodate(struct cache_entry *ce,
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_uptodate_1(ce, o, ERRORMSG(o, ERROR_NOT_UPTODATE_FILE));
+	return verify_uptodate_1(ce, o, ERROR_NOT_UPTODATE_FILE);
 }
 
 static int verify_uptodate_sparse(struct cache_entry *ce,
 				  struct unpack_trees_options *o)
 {
-	return verify_uptodate_1(ce, o, ERRORMSG(o, ERROR_SPARSE_NOT_UPTODATE_FILE));
+	return verify_uptodate_1(ce, o, ERROR_SPARSE_NOT_UPTODATE_FILE);
 }
 
 static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_options *o)
@@ -914,13 +920,15 @@ static void invalidate_ce_path(struct cache_entry *ce, struct unpack_trees_optio
  * Currently, git does not checkout subprojects during a superproject
  * checkout, so it is not going to overwrite anything.
  */
-static int verify_clean_submodule(struct cache_entry *ce, const char *action,
+static int verify_clean_submodule(struct cache_entry *ce,
+				      enum unpack_trees_error_types error_type,
 				      struct unpack_trees_options *o)
 {
 	return 0;
 }
 
-static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
+static int verify_clean_subdirectory(struct cache_entry *ce,
+				      enum unpack_trees_error_types error_type,
 				      struct unpack_trees_options *o)
 {
 	/*
@@ -941,7 +949,7 @@ static int verify_clean_subdirectory(struct cache_entry *ce, const char *action,
 		 */
 		if (!hashcmp(sha1, ce->sha1))
 			return 0;
-		return verify_clean_submodule(ce, action, o);
+		return verify_clean_submodule(ce, error_type, o);
 	}
 
 	/*
@@ -1010,9 +1018,9 @@ static int icase_exists(struct unpack_trees_options *o, struct cache_entry *dst,
  * We do not want to remove or overwrite a working tree file that
  * is not tracked, unless it is ignored.
  */
-static int verify_absent_1(struct cache_entry *ce, const char *action,
-				 struct unpack_trees_options *o,
-				 const char *error_msg)
+static int verify_absent_1(struct cache_entry *ce,
+				 enum unpack_trees_error_types error_type,
+				 struct unpack_trees_options *o)
 {
 	struct stat st;
 
@@ -1050,7 +1058,7 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 			 * files that are in "foo/" we would lose
 			 * them.
 			 */
-			if (verify_clean_subdirectory(ce, action, o) < 0)
+			if (verify_clean_subdirectory(ce, error_type, o) < 0)
 				return -1;
 			return 0;
 		}
@@ -1067,22 +1075,28 @@ static int verify_absent_1(struct cache_entry *ce, const char *action,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, ERROR_WOULD_LOSE_UNTRACKED), ce->name, action);
+			error(ERRORMSG(o, error_type), ce->name);
 	}
 	return 0;
 }
-static int verify_absent(struct cache_entry *ce, const char *action,
+static int verify_absent(struct cache_entry *ce,
+			 enum unpack_trees_error_types error_type,
 			 struct unpack_trees_options *o)
 {
 	if (!o->skip_sparse_checkout && will_have_skip_worktree(ce, o))
 		return 0;
-	return verify_absent_1(ce, action, o, ERRORMSG(o, ERROR_WOULD_LOSE_UNTRACKED));
+	return verify_absent_1(ce, error_type, o);
 }
 
-static int verify_absent_sparse(struct cache_entry *ce, const char *action,
+static int verify_absent_sparse(struct cache_entry *ce,
+			 enum unpack_trees_error_types error_type,
 			 struct unpack_trees_options *o)
 {
-	return verify_absent_1(ce, action, o, ERRORMSG(o, ERROR_WOULD_LOSE_ORPHANED));
+	enum unpack_trees_error_types orphaned_error = error_type;
+	if (orphaned_error == ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN)
+		orphaned_error = ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN;
+
+	return verify_absent_1(ce, orphaned_error, o);
 }
 
 static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
@@ -1091,7 +1105,7 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
 	int update = CE_UPDATE;
 
 	if (!old) {
-		if (verify_absent(merge, "overwritten", o))
+		if (verify_absent(merge, ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN, o))
 			return -1;
 		invalidate_ce_path(merge, o);
 	} else if (!(old->ce_flags & CE_CONFLICTED)) {
@@ -1129,7 +1143,7 @@ static int deleted_entry(struct cache_entry *ce, struct cache_entry *old,
 {
 	/* Did it exist in the index? */
 	if (!old) {
-		if (verify_absent(ce, "removed", o))
+		if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
 			return -1;
 		return 0;
 	}
@@ -1278,7 +1292,7 @@ int threeway_merge(struct cache_entry **stages, struct unpack_trees_options *o)
 			if (index)
 				return deleted_entry(index, index, o);
 			if (ce && !head_deleted) {
-				if (verify_absent(ce, "removed", o))
+				if (verify_absent(ce, ERROR_WOULD_LOSE_UNTRACKED_REMOVED, o))
 					return -1;
 			}
 			return 0;
diff --git a/unpack-trees.h b/unpack-trees.h
index 09e2252..8be6b3c 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -13,10 +13,12 @@ enum unpack_trees_error_types {
 	ERROR_WOULD_OVERWRITE = 0,
 	ERROR_NOT_UPTODATE_FILE,
 	ERROR_NOT_UPTODATE_DIR,
-	ERROR_WOULD_LOSE_UNTRACKED,
+	ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN,
+	ERROR_WOULD_LOSE_UNTRACKED_REMOVED,
 	ERROR_BIND_OVERLAP,
 	ERROR_SPARSE_NOT_UPTODATE_FILE,
-	ERROR_WOULD_LOSE_ORPHANED,
+	ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN,
+	ERROR_WOULD_LOSE_ORPHANED_REMOVED,
 	NB_UNPACK_TREES_ERROR_TYPES
 };
 
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 4/5 v2] unpack_trees: group error messages by type

[Matthieu Moy]

When an error is encountered, it calls add_rejected_file() which either
- directly displays the error message and stops if in plumbing mode
  (i.e. if show_all_errors is not initialized at 1)
- or stores it so that it will be displayed at the end with display_error_msgs(),

Storing the files by error type permits to have a list of files for
which there is the same error instead of having a serie of almost
identical errors.

As each bind_overlap error combines a file and an old file, a list cannot be
done, therefore, theses errors are not stored but directly displayed.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 Documentation/technical/api-tree-walking.txt |    2 +
 builtin/checkout.c                           |    1 +
 builtin/merge.c                              |    1 +
 merge-recursive.c                            |   25 ++++++--
 t/t3030-merge-recursive.sh                   |    2 +-
 t/t3400-rebase.sh                            |    3 +-
 t/t3404-rebase-interactive.sh                |    3 +-
 tree-walk.c                                  |   11 +++-
 tree-walk.h                                  |    1 +
 unpack-trees.c                               |   78 ++++++++++++++++++++++++-
 unpack-trees.h                               |   13 ++++-
 11 files changed, 123 insertions(+), 17 deletions(-)

diff --git a/Documentation/technical/api-tree-walking.txt b/Documentation/technical/api-tree-walking.txt
index 55b7286..14af37c 100644
--- a/Documentation/technical/api-tree-walking.txt
+++ b/Documentation/technical/api-tree-walking.txt
@@ -42,6 +42,8 @@ information.
 
 * `data` can be anything the `fn` callback would want to use.
 
+* `show_all_errors` tells whether to stop at the first error or not.
+
 Initializing
 ------------
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 22bf47c..894bb84 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -392,6 +392,7 @@ static int merge_working_tree(struct checkout_opts *opts,
 		topts.dir = xcalloc(1, sizeof(*topts.dir));
 		topts.dir->flags |= DIR_SHOW_IGNORED;
 		topts.dir->exclude_per_dir = ".gitignore";
+		topts.show_all_errors = 1;
 		tree = parse_tree_indirect(old->commit ?
 					   old->commit->object.sha1 :
 					   (unsigned char *)EMPTY_TREE_SHA1_BIN);
diff --git a/builtin/merge.c b/builtin/merge.c
index de5a0f6..1bcf7fd 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -704,6 +704,7 @@ int checkout_fast_forward(const unsigned char *head, const unsigned char *remote
 	opts.verbose_update = 1;
 	opts.merge = 1;
 	opts.fn = twoway_merge;
+	opts.show_all_errors = 1;
 	set_porcelain_error_msgs(opts.msgs, "merge");
 
 	trees[nr_trees] = parse_tree_indirect(head);
diff --git a/merge-recursive.c b/merge-recursive.c
index 697d948..10392d9 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1184,29 +1184,42 @@ void set_porcelain_error_msgs(const char **msgs, const char *cmd)
 	char *tmp;
 	const char *cmd2 = strcmp(cmd, "checkout") ? cmd : "switch branches";
 	if (advice_commit_before_merge)
-		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.\n"
+		msg = "Your local changes to the following files would be overwritten by %s:\n%%s"
 			"Please, commit your changes or stash them before you can %s.";
 	else
-		msg = "Your local changes to '%%s' would be overwritten by %s.  Aborting.";
-	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 3);
+		msg = "Your local changes to the following files would be overwritten by %s:\n%%s";
+	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen(cmd2) - 2);
 	sprintf(tmp, msg, cmd, cmd2);
 	msgs[ERROR_WOULD_OVERWRITE] = tmp;
 	msgs[ERROR_NOT_UPTODATE_FILE] = tmp;
 
 	msgs[ERROR_NOT_UPTODATE_DIR] =
-		"Updating '%s' would lose untracked files in it.  Aborting.";
+		"Updating the following directories would lose untracked files in it:\n%s";
 
 	if (advice_commit_before_merge)
-		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting"
+		msg = "The following untracked working tree files would be %s by %s:\n%%s"
 			"Please move or remove them before you can %s.";
 	else
-		msg = "Untracked working tree file '%%s' would be %s by %s.  Aborting";
+		msg = "The following untracked working tree files would be %s by %s:\n%%s";
 	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("removed") + strlen(cmd2) - 4);
 	sprintf(tmp, msg, "removed", cmd, cmd2);
 	msgs[ERROR_WOULD_LOSE_UNTRACKED_REMOVED] = tmp;
 	tmp = xmalloc(strlen(msg) + strlen(cmd) + strlen("overwritten") + strlen(cmd2) - 4);
 	sprintf(tmp, msg, "overwritten", cmd, cmd2);
 	msgs[ERROR_WOULD_LOSE_UNTRACKED_OVERWRITTEN] = tmp;
+
+	/*
+	 * Special case: ERROR_BIND_OVERLAP refers to a pair of paths, we
+	 * cannot easily display it as a list.
+	 */
+	msgs[ERROR_BIND_OVERLAP] = "Entry '%s' overlaps with '%s'.  Cannot bind.";
+
+	msgs[ERROR_SPARSE_NOT_UPTODATE_FILE] =
+		"Cannot update sparse checkout: the following entries are not up-to-date:\n%s";
+	msgs[ERROR_WOULD_LOSE_ORPHANED_OVERWRITTEN] =
+		"The following Working tree files would be overwritten by sparse checkout update:\n%s";
+	msgs[ERROR_WOULD_LOSE_ORPHANED_REMOVED] =
+		"The following Working tree files would be removed by sparse checkout update:\n%s";
 }
 
 int merge_trees(struct merge_options *o,
diff --git a/t/t3030-merge-recursive.sh b/t/t3030-merge-recursive.sh
index d541544..efe2900 100755
--- a/t/t3030-merge-recursive.sh
+++ b/t/t3030-merge-recursive.sh
@@ -294,7 +294,7 @@ test_expect_success 'fail if the index has unresolved entries' '
 	grep "You have not concluded your merge" out &&
 	rm -f .git/MERGE_HEAD &&
 	test_must_fail git merge "$c5" 2> out &&
-	grep "Your local changes to .* would be overwritten by merge." out
+	grep "Your local changes to the following files would be overwritten by merge:" out
 '
 
 test_expect_success 'merge-recursive remove conflict' '
diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index d98c7b5..45ef282 100755
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -129,7 +129,8 @@ test_expect_success 'rebase a single mode change' '
 test_expect_success 'Show verbose error when HEAD could not be detached' '
      : > B &&
      test_must_fail git rebase topic 2> output.err > output.out &&
-     grep "Untracked working tree file .B. would be overwritten" output.err
+     grep "The following untracked working tree files would be overwritten by checkout:" output.err &&
+     grep B output.err
 '
 rm -f B
 
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9f03ce6..3af3f60 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -150,8 +150,9 @@ test_expect_success 'abort with error when new base cannot be checked out' '
 	git rm --cached file1 &&
 	git commit -m "remove file in base" &&
 	test_must_fail git rebase -i master > output 2>&1 &&
-	grep "Untracked working tree file .file1. would be overwritten" \
+	grep "The following untracked working tree files would be overwritten by checkout:" \
 		output &&
+	grep "file1" output &&
 	! test -d .git/rebase-merge &&
 	git reset --hard HEAD^
 '
diff --git a/tree-walk.c b/tree-walk.c
index 67a9a0c..a9bbf4e 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "tree-walk.h"
+#include "unpack-trees.h"
 #include "tree.h"
 
 static const char *get_mode(const char *str, unsigned int *modep)
@@ -310,6 +311,7 @@ static void free_extended_entry(struct tree_desc_x *t)
 int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 {
 	int ret = 0;
+	int error = 0;
 	struct name_entry *entry = xmalloc(n*sizeof(*entry));
 	int i;
 	struct tree_desc_x *tx = xcalloc(n, sizeof(*tx));
@@ -377,8 +379,11 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 		if (!mask)
 			break;
 		ret = info->fn(n, mask, dirmask, entry, info);
-		if (ret < 0)
-			break;
+		if (ret < 0) {
+			error = ret;
+			if (!info->show_all_errors)
+				break;
+		}
 		mask &= ret;
 		ret = 0;
 		for (i = 0; i < n; i++)
@@ -389,7 +394,7 @@ int traverse_trees(int n, struct tree_desc *t, struct traverse_info *info)
 	for (i = 0; i < n; i++)
 		free_extended_entry(tx + i);
 	free(tx);
-	return ret;
+	return error;
 }
 
 static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
diff --git a/tree-walk.h b/tree-walk.h
index 42110a4..88ea7e9 100644
--- a/tree-walk.h
+++ b/tree-walk.h
@@ -45,6 +45,7 @@ struct traverse_info {
 	unsigned long conflicts;
 	traverse_callback_t fn;
 	void *data;
+	int show_all_errors;
 };
 
 int get_tree_entry(const unsigned char *, const char *, unsigned char *, unsigned *);
diff --git a/unpack-trees.c b/unpack-trees.c
index 342f5ec..7b10f92 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -65,6 +65,73 @@ static void add_entry(struct unpack_trees_options *o, struct cache_entry *ce,
 }
 
 /*
+ * add error messages on path <path>
+ * corresponding to the type <e> with the message <msg>
+ * indicating if it should be display in porcelain or not
+ */
+static int add_rejected_path(struct unpack_trees_options *o,
+			     enum unpack_trees_error_types e,
+			     const char *path)
+{
+	struct rejected_paths_list *newentry;
+	int porcelain = o && (o)->msgs[e];
+	/*
+	 * simply display the given error message if in plumbing mode
+	 */
+	if (!porcelain)
+		o->show_all_errors = 0;
+	if (!o->show_all_errors)
+		return error(ERRORMSG(o, e), path);
+
+	/*
+	 * Otherwise, insert in a list for future display by
+	 * display_error_msgs()
+	 */
+	newentry = xmalloc(sizeof(struct rejected_paths_list));
+	newentry->path = (char *)path;
+	newentry->next = o->unpack_rejects[e];
+	o->unpack_rejects[e] = newentry;
+	return -1;
+}
+
+/*
+ * free all the structures allocated for the error <e>
+ */
+static void free_rejected_paths(struct unpack_trees_options *o,
+				enum unpack_trees_error_types e)
+{
+	while (o->unpack_rejects[e]) {
+		struct rejected_paths_list *del = o->unpack_rejects[e];
+		o->unpack_rejects[e] = o->unpack_rejects[e]->next;
+		free(del);
+	}
+	free(o->unpack_rejects[e]);
+}
+
+/*
+ * display all the error messages stored in a nice way
+ */
+static void display_error_msgs(struct unpack_trees_options *o)
+{
+	int e;
+	int something_displayed = 0;
+	for (e = 0; e < NB_UNPACK_TREES_ERROR_TYPES; e++) {
+		if (o->unpack_rejects[e]) {
+			struct rejected_paths_list *rp;
+			struct strbuf path = STRBUF_INIT;
+			something_displayed = 1;
+			for (rp = o->unpack_rejects[e]; rp; rp = rp->next)
+				strbuf_addf(&path, "\t%s\n", rp->path);
+			error(ERRORMSG(o, e), path.buf);
+			strbuf_release(&path);
+			free_rejected_paths(o, e);
+		}
+	}
+	if (something_displayed)
+		printf("Aborting\n");
+}
+
+/*
  * Unlink the last component and schedule the leading directories for
  * removal, such that empty directories get removed.
  */
@@ -755,6 +822,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 		setup_traverse_info(&info, prefix);
 		info.fn = unpack_callback;
 		info.data = o;
+		info.show_all_errors = o->show_all_errors;
 
 		if (o->prefix) {
 			/*
@@ -834,6 +902,8 @@ done:
 	return ret;
 
 return_failed:
+	if (o->show_all_errors)
+		display_error_msgs(o);
 	mark_all_ce_unused(o->src_index);
 	ret = unpack_failed(o, NULL);
 	goto done;
@@ -843,7 +913,7 @@ return_failed:
 
 static int reject_merge(struct cache_entry *ce, struct unpack_trees_options *o)
 {
-	return error(ERRORMSG(o, ERROR_WOULD_OVERWRITE), ce->name);
+	return add_rejected_path(o, ERROR_WOULD_OVERWRITE, ce->name);
 }
 
 static int same(struct cache_entry *a, struct cache_entry *b)
@@ -890,7 +960,7 @@ static int verify_uptodate_1(struct cache_entry *ce,
 	if (errno == ENOENT)
 		return 0;
 	return o->gently ? -1 :
-		error(ERRORMSG(o, error_type), ce->name);
+		add_rejected_path(o, error_type, ce->name);
 }
 
 static int verify_uptodate(struct cache_entry *ce,
@@ -993,7 +1063,7 @@ static int verify_clean_subdirectory(struct cache_entry *ce,
 	i = read_directory(&d, pathbuf, namelen+1, NULL);
 	if (i)
 		return o->gently ? -1 :
-			error(ERRORMSG(o, ERROR_NOT_UPTODATE_DIR), ce->name);
+			add_rejected_path(o, ERROR_NOT_UPTODATE_DIR, ce->name);
 	free(pathbuf);
 	return cnt;
 }
@@ -1075,7 +1145,7 @@ static int verify_absent_1(struct cache_entry *ce,
 		}
 
 		return o->gently ? -1 :
-			error(ERRORMSG(o, error_type), ce->name);
+			add_rejected_path(o, error_type, ce->name);
 	}
 	return 0;
 }
diff --git a/unpack-trees.h b/unpack-trees.h
index 8be6b3c..6e049b0 100644
--- a/unpack-trees.h
+++ b/unpack-trees.h
@@ -22,6 +22,11 @@ enum unpack_trees_error_types {
 	NB_UNPACK_TREES_ERROR_TYPES
 };
 
+struct rejected_paths_list {
+	char *path;
+	struct rejected_paths_list *next;
+};
+
 struct unpack_trees_options {
 	unsigned int reset,
 		     merge,
@@ -36,12 +41,18 @@ struct unpack_trees_options {
 		     diff_index_cached,
 		     debug_unpack,
 		     skip_sparse_checkout,
-		     gently;
+		     gently,
+		     show_all_errors;
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;
 	merge_fn_t fn;
 	const char *msgs[NB_UNPACK_TREES_ERROR_TYPES];
+	/*
+	 * Store error messages in an array, each case
+	 * corresponding to a error message type
+	 */
+	struct rejected_paths_list *unpack_rejects[NB_UNPACK_TREES_ERROR_TYPES];
 
 	int head_idx;
 	int merge_size;
-- 
1.7.2.1.52.g95e25.dirty

[PATCH 5/5 v2] t7609: test merge and checkout error messages

[Matthieu Moy]

From: Diane Gasselin <diane.gasselin@ensimag.imag.fr>

Test porcelain and plumbing error messages for different types of errors
of merge and checkout.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 t/t7609-merge-co-error-msgs.sh |  125 ++++++++++++++++++++++++++++++++++++++++
 1 files changed, 125 insertions(+), 0 deletions(-)
 create mode 100755 t/t7609-merge-co-error-msgs.sh

diff --git a/t/t7609-merge-co-error-msgs.sh b/t/t7609-merge-co-error-msgs.sh
new file mode 100755
index 0000000..1a109b4
--- /dev/null
+++ b/t/t7609-merge-co-error-msgs.sh
@@ -0,0 +1,125 @@
+#!/bin/sh
+
+test_description='unpack-trees error messages'
+
+. ./test-lib.sh
+
+
+test_expect_success 'setup' '
+	echo one >one &&
+	git add one &&
+	git commit -a -m First &&
+
+	git checkout -b branch &&
+	echo two >two &&
+	echo three >three &&
+	echo four >four &&
+	echo five >five &&
+	git add two three four five &&
+	git commit -m Second &&
+
+	git checkout master &&
+	echo other >two &&
+	echo other >three &&
+	echo other >four &&
+	echo other >five
+'
+
+cat >expect <<\EOF
+error: The following untracked working tree files would be overwritten by merge:
+	two
+	three
+	four
+	five
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'untracked files overwritten by merge' '
+	test_must_fail git merge branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by merge:
+	two
+	three
+	four
+Please, commit your changes or stash them before you can merge.
+error: The following untracked working tree files would be overwritten by merge:
+	five
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'untracked files or local changes ovewritten by merge' '
+	git add two &&
+	git add three &&
+	git add four &&
+	test_must_fail git merge branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by checkout:
+	rep/two
+	rep/one
+Please, commit your changes or stash them before you can switch branches.
+EOF
+
+test_expect_success 'cannot switch branches because of local changes' '
+	git add five &&
+	mkdir rep &&
+	echo one >rep/one &&
+	echo two >rep/two &&
+	git add rep/one rep/two &&
+	git commit -m Fourth &&
+	git checkout master &&
+	echo uno >rep/one &&
+	echo dos >rep/two &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Your local changes to the following files would be overwritten by checkout:
+	rep/two
+	rep/one
+Please, commit your changes or stash them before you can switch branches.
+EOF
+
+test_expect_success 'not uptodate file porcelain checkout error' '
+	git add rep/one rep/two &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out expect
+'
+
+cat >expect <<\EOF
+error: Updating the following directories would lose untracked files in it:
+	rep2
+	rep
+
+EOF
+
+test_expect_success 'not_uptodate_dir porcelain checkout error' '
+	git init uptodate &&
+	cd uptodate &&
+	mkdir rep &&
+	mkdir rep2 &&
+	touch rep/foo &&
+	touch rep2/foo &&
+	git add rep/foo rep2/foo &&
+	git commit -m init &&
+	git checkout -b branch &&
+	git rm rep -r &&
+	git rm rep2 -r &&
+	>rep &&
+	>rep2 &&
+	git add rep rep2&&
+	git commit -m "added test as a file" &&
+	git checkout master &&
+	>rep/untracked-file &&
+	>rep2/untracked-file &&
+	test_must_fail git checkout branch 2>out &&
+	test_cmp out ../expect
+'
+
+test_done
-- 
1.7.2.1.52.g95e25.dirty