[PATCH 0/3] [GSoC] receive.denyCurrentBranch: respect all worktrees

[PATCH 0/3] [GSoC] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

The receive.denyCurrentBranch config option controls what happens if you
push to a branch that is checkout into a non-bare repository. By default, it
rejects it. It can be disabled via ignore or warn. Another yet trickier
option is updateInstead.

When receive.denyCurrentBranch is set to updateInstead, a push that tries to
update the branch that is currently checked out is accepted only when the
index and the working tree exactly matches the currently checked out commit,
in which case the index and the working tree are updated to match the pushed
commit. Otherwise, the push is refused.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected. [ fixes:
#331 ]

Incidently, this change also fixes another bug i.e. 
receive.denyCurrentBranch = true was ignored when pushing into a non-bare
repository's unborn current branch.

Thanks, @dscho for helping me out.

Regards, Hariom

Hariom Verma (3):
  get_main_worktree(): allow it to be called in the Git directory
  t5509: initialized `pushee` as bare repository
  receive.denyCurrentBranch: respect all worktrees

 builtin/receive-pack.c           | 37 +++++++++++++++++---------------
 t/t5509-fetch-push-namespaces.sh |  2 +-
 t/t5516-fetch-push.sh            | 11 ++++++++++
 worktree.c                       |  1 +
 4 files changed, 33 insertions(+), 18 deletions(-)


base-commit: 232378479ee6c66206d47a9be175e3a39682aea6
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-535%2Fharry-hov%2Fdeny-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-535/harry-hov/deny-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/535
-- 
gitgitgadget

[PATCH 1/3] get_main_worktree(): allow it to be called in the Git directory

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

When called in the Git directory of a non-bare repository, this function
would not return the directory of the main worktree, but of the Git
directory instead.

The reason: when the Git directory is the current working directory, the
absolute path of the common directory will be reported with a trailing
`/.git/.`, which the code of `get_main_worktree()` does not handle
correctly.

Let's fix this.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 worktree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/worktree.c b/worktree.c
index 5b4793caa3..7c8cd21317 100644
--- a/worktree.c
+++ b/worktree.c
@@ -51,6 +51,7 @@ static struct worktree *get_main_worktree(void)
 	struct strbuf worktree_path = STRBUF_INIT;
 
 	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	strbuf_strip_suffix(&worktree_path, "/.");
 	if (!strbuf_strip_suffix(&worktree_path, "/.git"))
 		strbuf_strip_suffix(&worktree_path, "/.");
 
-- 
gitgitgadget

[PATCH 2/3] t5509: initialized `pushee` as bare repository

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

`receive.denyCurrentBranch` currently has a bug where it allows pushing
into the current branch of a non-bare repository as long as it does not
have any commits. This would cause t5509 to fail once that bug is fixed
because it pushes into an unborn current branch.

In t5509, no operations are performed inside `pushee`, as it is only a
target for `git push` and `git ls-remote` calls. Therefore it does not
need to have a worktree. So, it is safe to change `pushee` to a bare
repository.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 t/t5509-fetch-push-namespaces.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index 75cbfcc392..e3975bd21d 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -20,7 +20,7 @@ test_expect_success setup '
 	) &&
 	commit0=$(cd original && git rev-parse HEAD^) &&
 	commit1=$(cd original && git rev-parse HEAD) &&
-	git init pushee &&
+	git init --bare pushee &&
 	git init puller
 '
 
-- 
gitgitgadget

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Junio C Hamano]

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

> From: Hariom Verma <hariom18599@gmail.com>
>
> `receive.denyCurrentBranch` currently has a bug where it allows pushing
> into the current branch of a non-bare repository as long as it does not
> have any commits.

Can patch 3/3 be split into two, so that the fix would protect an
already populated branch that is checked out anywhere (not in the
primary worktree--which is the bug you are fixing) from getting
updated but still allow an unborn branch to be updated, and then
have patch 4/3 that forbids an update to even an unborn branch
"checked out" in any working tree?  This update to the test can then
become part of patch 4/3.

Thanks.

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Junio C Hamano]

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

> "Hariom Verma via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
>> From: Hariom Verma <hariom18599@gmail.com>
>>
>> `receive.denyCurrentBranch` currently has a bug where it allows pushing
>> into the current branch of a non-bare repository as long as it does not
>> have any commits.
>
> Can patch 3/3 be split into two, so that the fix would protect an
> already populated branch that is checked out anywhere (not in the
> primary worktree--which is the bug you are fixing) from getting
> updated but still allow an unborn branch to be updated, and then
> have patch 4/3 that forbids an update to even an unborn branch
> "checked out" in any working tree?  This update to the test can then
> become part of patch 4/3.

Oh, another thing.  The patch 4/3 that starts forbidding a push into
a checked out unborn branch should also have a test that makes sure
that such an attempt fails.  IOW, making the test repository used in
the test you changed to a bare one, to allow existing test to still
test what it wants to test, like you did in this patch is OK, but we
would want to have a new test that prepares a repository with the
primary and the secondary worktrees, check out an unborn branch in
each of the worktrees, and make sure receive.denyCurrentBranch would
prevent "git push" to update these branches.

Thanks.

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Johannes Schindelin]

Hi Junio,

On Thu, 13 Feb 2020, Junio C Hamano wrote:

> "Hariom Verma via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: Hariom Verma <hariom18599@gmail.com>
> >
> > `receive.denyCurrentBranch` currently has a bug where it allows pushing
> > into the current branch of a non-bare repository as long as it does not
> > have any commits.
>
> Can patch 3/3 be split into two,

I actually don't think so. The `refs_resolve_unsafe()` function simply
requires a tip commit, so it is the wrong function to call in this
context. And the fix for it is to use a more appropriate function, which
3/3 already does (although for an unrelated reason).

In other words, a fix for one bug would be a fix for the other, and
(probably) vice versa.

> so that the fix would protect an already populated branch that is
> checked out anywhere (not in the primary worktree--which is the bug you
> are fixing) from getting updated but still allow an unborn branch to be
> updated, and then have patch 4/3 that forbids an update to even an
> unborn branch "checked out" in any working tree?  This update to the
> test can then become part of patch 4/3.

I agree that this merits a regression test.

Thanks,
Dscho

>
> Thanks.
>

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Junio C Hamano]

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

>> Can patch 3/3 be split into two,
>
> I actually don't think so. The `refs_resolve_unsafe()` function simply
> ...
> In other words, a fix for one bug would be a fix for the other, and
> (probably) vice versa.

What mislead me was the way this step presented itself.  It sounded
as if the primary (and possibly the only) thing the series wanted to
fix was to make .denyCurrentBranch pay attention to other worktrees,
and while fixing that, it broke as collateral damage a "feature"
that denyCurrentBranch allows an unborn branch to be updated no
matter what and called it a bugfix when it was not a bug.

If the series is fixing two bugs, perhaps 2/3 can first fix it for a
primary worktree case by seeing what HEAD symref for the primary
worktree points at is the target of a push without iterating over
all the worktrees, have the test change in 2/3 (i.e. "fixing the
'unborn' case revealed a wrong expectation in an existing test"),
and a couple of new tests to see what a push from sideways would do
to an unborn branch that is checked out in the primary worktree when
.denyCurrentBranch is and isn't in effect.

Then 3/3 can use the same logic to see if one worktree is OK with
the proposed ref update by the push used in 2/3 (which no longer
uses refs_resolve_unsafe()') to check for all worktrees.  The new
tests introduced in 2/3 would be extended to see what happens when
the unborn branch getting updated by the push happens to be checked
out in a secondary worktree.

That would have avoided misleading this reader.

Thanks.

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Hariom verma]

On Fri, Feb 14, 2020 at 8:33 PM Junio C Hamano <gitster@pobox.com> wrote:
> If the series is fixing two bugs, perhaps 2/3 can first fix it for a
> primary worktree case by seeing what HEAD symref for the primary
> worktree points at is the target of a push without iterating over
> all the worktrees, have the test change in 2/3 (i.e. "fixing the
> 'unborn' case revealed a wrong expectation in an existing test"),
> and a couple of new tests to see what a push from sideways would do
> to an unborn branch that is checked out in the primary worktree when
> .denyCurrentBranch is and isn't in effect.
>
> Then 3/3 can use the same logic to see if one worktree is OK with
> the proposed ref update by the push used in 2/3 (which no longer
> uses refs_resolve_unsafe()') to check for all worktrees.  The new
> tests introduced in 2/3 would be extended to see what happens when
> the unborn branch getting updated by the push happens to be checked
> out in a secondary worktree.

As far as my understanding goes, what we want is:
1) fixing `.denyCurrentBranch` for unborn branches in primary worktree. (2/3)
2) writing test (expect it to fail if `unborn` & 'non-bare' case) (2/3)
3) making `.denyCurrentBranch` respect all worktrees. (3/3)
4) extending tests written in step 2 for secondary worktrees. (3/3)

Correct me if I'm wrong.
As I'm not entirely familiar with working and structure of
`.denyCurrentBranch`. So I might need more explicit explanation.

Thanks,
Hariom

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Junio C Hamano]

Hariom verma <hariom18599@gmail.com> writes:

> On Fri, Feb 14, 2020 at 8:33 PM Junio C Hamano <gitster@pobox.com> wrote:
>> If the series is fixing two bugs, perhaps 2/3 can first fix it for a
>> primary worktree case by seeing what HEAD symref for the primary
>> worktree points at is the target of a push without iterating over
>> all the worktrees, have the test change in 2/3 (i.e. "fixing the
>> 'unborn' case revealed a wrong expectation in an existing test"),
>> and a couple of new tests to see what a push from sideways would do
>> to an unborn branch that is checked out in the primary worktree when
>> .denyCurrentBranch is and isn't in effect.
>>
>> Then 3/3 can use the same logic to see if one worktree is OK with
>> the proposed ref update by the push used in 2/3 (which no longer
>> uses refs_resolve_unsafe()') to check for all worktrees.  The new
>> tests introduced in 2/3 would be extended to see what happens when
>> the unborn branch getting updated by the push happens to be checked
>> out in a secondary worktree.
>
> As far as my understanding goes, what we want is:
> 1) fixing `.denyCurrentBranch` for unborn branches in primary worktree. (2/3)
> 2) writing test (expect it to fail if `unborn` & 'non-bare' case) (2/3)
> 3) making `.denyCurrentBranch` respect all worktrees. (3/3)
> 4) extending tests written in step 2 for secondary worktrees. (3/3)
>
> Correct me if I'm wrong.

If the above is what _you_ want, then there is nothing for me to
correct ;-)

What I suggested was somewhat different, though.

  1) get_main_worktree() fix you have as [1/3] in the current round.

  2) fix `.denyCurrentBranch` for unborn branches in the primary
     worktree, new tests for the cases I outlined in the message you
     are responding to, and adjusting the test (i.e. what you have
     as [2/3] in the current round).

  3) fix `.denyCurrentBranch` to pay attention to HEAD of not just
     the primary worktree but of all the worktrees, and add tests.

Thanks.

Re: [PATCH 2/3] t5509: initialized `pushee` as bare repository

[Hariom verma]

On Mon, Feb 17, 2020 at 5:19 AM Junio C Hamano <gitster@pobox.com> wrote:
> What I suggested was somewhat different, though.
>
>   1) get_main_worktree() fix you have as [1/3] in the current round.
>
>   2) fix `.denyCurrentBranch` for unborn branches in the primary
>      worktree, new tests for the cases I outlined in the message you
>      are responding to, and adjusting the test (i.e. what you have
>      as [2/3] in the current round).
>
>   3) fix `.denyCurrentBranch` to pay attention to HEAD of not just
>      the primary worktree but of all the worktrees, and add tests.

I doubt that it's possible to solve these 2 issues separately.
As dscho said: "a fix for one bug would be a fix for the other, and
(probably) vice versa."

As I discussed with dscho, the best possible solution for this
situation is to demonstrate the bug and fix it in succeeding commit.

I have sent this v2[1] for this patch.

Thanks,
Hariom

[1]: https://lore.kernel.org/git/pull.535.v2.git.1582410908.gitgitgadget@gmail.com/

[PATCH 3/3] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

The receive.denyCurrentBranch config option controls what happens if
you push to a branch that is checked out into a non-bare repository.
By default, it rejects it. It can be disabled via `ignore` or `warn`.
Another yet trickier option is `updateInstead`.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected.

With this change, all worktrees are respected.

That change also leads to revealing another bug,
i.e. `receive.denyCurrentBranch = true` was ignored when pushing into a
non-bare repository's unborn current branch.  As `is_ref_checked_out()`
returns 0 which means `receive-pack` does not get into conditional
statement to switch `deny_current_branch` accordingly(ignore, warn,
refuse, unconfigured, updateInstead).

receive.denyCurrentBranch uses the function `refs_resolve_ref_unsafe()`
(called via `resolve_refdup()`) to resolve the symbolic ref HEAD, but
that function fails when HEAD does not point at a valid commit.
As we replace the call to `refs_resolve_ref_unsafe()` with
`find_shared_symref()`, which has no problem finding the worktree for a
given branch even if it is unborn yet, this bug is fixed at the same
time: receive.denyCurrentBranch now also handles worktrees with unborn
branches as intended.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 builtin/receive-pack.c | 37 ++++++++++++++++++++-----------------
 t/t5516-fetch-push.sh  | 11 +++++++++++
 2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 411e0b4d99..b5ca3123b7 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -27,6 +27,7 @@
 #include "object-store.h"
 #include "protocol.h"
 #include "commit-reach.h"
+#include "worktree.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
@@ -816,16 +817,6 @@ static int run_update_hook(struct command *cmd)
 	return finish_command(&proc);
 }
 
-static int is_ref_checked_out(const char *ref)
-{
-	if (is_bare_repository())
-		return 0;
-
-	if (!head_name)
-		return 0;
-	return !strcmp(head_name, ref);
-}
-
 static char *refuse_unconfigured_deny_msg =
 	N_("By default, updating the current branch in a non-bare repository\n"
 	   "is denied, because it will make the index and work tree inconsistent\n"
@@ -997,16 +988,27 @@ static const char *push_to_checkout(unsigned char *hash,
 		return NULL;
 }
 
-static const char *update_worktree(unsigned char *sha1)
+static const char *update_worktree(unsigned char *sha1, const struct worktree *worktree)
 {
-	const char *retval;
-	const char *work_tree = git_work_tree_cfg ? git_work_tree_cfg : "..";
+	const char *retval, *work_tree, *git_dir = NULL;
 	struct argv_array env = ARGV_ARRAY_INIT;
 
+	if (worktree && worktree->path)
+		work_tree = worktree->path;
+	else if (git_work_tree_cfg)
+		work_tree = git_work_tree_cfg;
+	else
+		work_tree = "..";
+
 	if (is_bare_repository())
 		return "denyCurrentBranch = updateInstead needs a worktree";
+	
+	if (worktree)
+		git_dir = get_worktree_git_dir(worktree);
+	if (!git_dir)
+		git_dir = get_git_dir();
 
-	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(get_git_dir()));
+	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(git_dir));
 
 	if (!find_hook(push_to_checkout_hook))
 		retval = push_to_deploy(sha1, &env, work_tree);
@@ -1026,6 +1028,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	struct object_id *old_oid = &cmd->old_oid;
 	struct object_id *new_oid = &cmd->new_oid;
 	int do_update_worktree = 0;
+	const struct worktree *worktree = is_bare_repository() ? NULL : find_shared_symref("HEAD", name);
 
 	/* only refs/... are allowed */
 	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
@@ -1037,7 +1040,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	free(namespaced_name);
 	namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
 
-	if (is_ref_checked_out(namespaced_name)) {
+	if (worktree) {
 		switch (deny_current_branch) {
 		case DENY_IGNORE:
 			break;
@@ -1069,7 +1072,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 			return "deletion prohibited";
 		}
 
-		if (head_name && !strcmp(namespaced_name, head_name)) {
+		if (worktree || (head_name && !strcmp(namespaced_name, head_name))) {
 			switch (deny_delete_current) {
 			case DENY_IGNORE:
 				break;
@@ -1118,7 +1121,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	}
 
 	if (do_update_worktree) {
-		ret = update_worktree(new_oid->hash);
+		ret = update_worktree(new_oid->hash, find_shared_symref("HEAD", name));
 		if (ret)
 			return ret;
 	}
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index c81ca360ac..6608e391f0 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1712,4 +1712,15 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
 	)
 '
 
+test_expect_success 'denyCurrentBranch and worktrees' '
+    git worktree add new-wt &&
+	git clone . cloned &&
+	test_commit -C cloned first &&
+	test_config receive.denyCurrentBranch refuse &&
+	test_must_fail git -C cloned push origin HEAD:new-wt &&
+	test_config receive.denyCurrentBranch updateInstead &&
+	git -C cloned push origin HEAD:new-wt &&
+	test_must_fail git -C cloned push --delete origin new-wt
+'
+
 test_done
-- 
gitgitgadget

[PATCH v2 0/4] [GSoC] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

The receive.denyCurrentBranch config option controls what happens if you
push to a branch that is checkout into a non-bare repository. By default, it
rejects it. It can be disabled via ignore or warn. Another yet trickier
option is updateInstead.

When receive.denyCurrentBranch is set to updateInstead, a push that tries to
update the branch that is currently checked out is accepted only when the
index and the working tree exactly matches the currently checked out commit,
in which case the index and the working tree are updated to match the pushed
commit. Otherwise, the push is refused.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected. [ fixes:
#331 ]

Incidently, this change also fixes another bug i.e. 
receive.denyCurrentBranch = true was ignored when pushing into a non-bare
repository using ref namespaces.

Thanks, @dscho for helping me out.

Regards, Hariom

Hariom Verma (4):
  get_main_worktree(): allow it to be called in the Git directory
  t5509: initialized `pushee` as bare repository
  bug: denyCurrentBranch and unborn branch with ref namespace
  receive.denyCurrentBranch: respect all worktrees

 builtin/receive-pack.c           | 37 +++++++++++++++++---------------
 t/t5509-fetch-push-namespaces.sh | 11 +++++++++-
 t/t5516-fetch-push.sh            | 11 ++++++++++
 worktree.c                       |  1 +
 4 files changed, 42 insertions(+), 18 deletions(-)


base-commit: 232378479ee6c66206d47a9be175e3a39682aea6
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-535%2Fharry-hov%2Fdeny-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-535/harry-hov/deny-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/535

Range-diff vs v1:

 1:  902c8a3f171 = 1:  8718facbc95 get_main_worktree(): allow it to be called in the Git directory
 2:  d156d04ca87 ! 2:  5c749e044a3 t5509: initialized `pushee` as bare repository
     @@ -3,9 +3,9 @@
          t5509: initialized `pushee` as bare repository
      
          `receive.denyCurrentBranch` currently has a bug where it allows pushing
     -    into the current branch of a non-bare repository as long as it does not
     -    have any commits. This would cause t5509 to fail once that bug is fixed
     -    because it pushes into an unborn current branch.
     +    into non-bare repository using namespaces as long as it does not have any
     +    commits. This would cause t5509 to fail once that bug is fixed because it
     +    pushes into an unborn current branch.
      
          In t5509, no operations are performed inside `pushee`, as it is only a
          target for `git push` and `git ls-remote` calls. Therefore it does not
 -:  ----------- > 3:  b3e573d44a9 bug: denyCurrentBranch and unborn branch with ref namespace
 3:  3352c0bffc1 ! 4:  61e5f75a6f9 receive.denyCurrentBranch: respect all worktrees
     @@ -14,10 +14,10 @@
      
          That change also leads to revealing another bug,
          i.e. `receive.denyCurrentBranch = true` was ignored when pushing into a
     -    non-bare repository's unborn current branch.  As `is_ref_checked_out()`
     -    returns 0 which means `receive-pack` does not get into conditional
     -    statement to switch `deny_current_branch` accordingly(ignore, warn,
     -    refuse, unconfigured, updateInstead).
     +    non-bare repository's unborn current branch using ref namespaces. As
     +    `is_ref_checked_out()` returns 0 which means `receive-pack` does not get
     +    into conditional statement to switch `deny_current_branch` accordingly
     +    (ignore, warn, refuse, unconfigured, updateInstead).
      
          receive.denyCurrentBranch uses the function `refs_resolve_ref_unsafe()`
          (called via `resolve_refdup()`) to resolve the symbolic ref HEAD, but
     @@ -26,7 +26,7 @@
          `find_shared_symref()`, which has no problem finding the worktree for a
          given branch even if it is unborn yet, this bug is fixed at the same
          time: receive.denyCurrentBranch now also handles worktrees with unborn
     -    branches as intended.
     +    branches as intended even while using ref namespaces.
      
          Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
          Signed-off-by: Hariom Verma <hariom18599@gmail.com>
     @@ -127,6 +127,19 @@
       			return ret;
       	}
      
     + diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
     + --- a/t/t5509-fetch-push-namespaces.sh
     + +++ b/t/t5509-fetch-push-namespaces.sh
     +@@
     + 	test_cmp expect actual
     + '
     + 
     +-test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '
     ++test_expect_success 'denyCurrentBranch and unborn branch with ref namespace' '
     + 	cd original &&
     + 	git init unborn &&
     + 	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
     +
       diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
       --- a/t/t5516-fetch-push.sh
       +++ b/t/t5516-fetch-push.sh
     @@ -135,7 +148,7 @@
       '
       
      +test_expect_success 'denyCurrentBranch and worktrees' '
     -+    git worktree add new-wt &&
     ++	git worktree add new-wt &&
      +	git clone . cloned &&
      +	test_commit -C cloned first &&
      +	test_config receive.denyCurrentBranch refuse &&

-- 
gitgitgadget

[PATCH v2 1/4] get_main_worktree(): allow it to be called in the Git directory

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

When called in the Git directory of a non-bare repository, this function
would not return the directory of the main worktree, but of the Git
directory instead.

The reason: when the Git directory is the current working directory, the
absolute path of the common directory will be reported with a trailing
`/.git/.`, which the code of `get_main_worktree()` does not handle
correctly.

Let's fix this.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 worktree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/worktree.c b/worktree.c
index 5b4793caa34..7c8cd213171 100644
--- a/worktree.c
+++ b/worktree.c
@@ -51,6 +51,7 @@ static struct worktree *get_main_worktree(void)
 	struct strbuf worktree_path = STRBUF_INIT;
 
 	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	strbuf_strip_suffix(&worktree_path, "/.");
 	if (!strbuf_strip_suffix(&worktree_path, "/.git"))
 		strbuf_strip_suffix(&worktree_path, "/.");
 
-- 
gitgitgadget

[PATCH v2 2/4] t5509: initialized `pushee` as bare repository

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

`receive.denyCurrentBranch` currently has a bug where it allows pushing
into non-bare repository using namespaces as long as it does not have any
commits. This would cause t5509 to fail once that bug is fixed because it
pushes into an unborn current branch.

In t5509, no operations are performed inside `pushee`, as it is only a
target for `git push` and `git ls-remote` calls. Therefore it does not
need to have a worktree. So, it is safe to change `pushee` to a bare
repository.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 t/t5509-fetch-push-namespaces.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index 75cbfcc392c..e3975bd21de 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -20,7 +20,7 @@ test_expect_success setup '
 	) &&
 	commit0=$(cd original && git rev-parse HEAD^) &&
 	commit1=$(cd original && git rev-parse HEAD) &&
-	git init pushee &&
+	git init --bare pushee &&
 	git init puller
 '
 
-- 
gitgitgadget

Re: [PATCH v2 2/4] t5509: initialized `pushee` as bare repository

[Junio C Hamano]

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

> From: Hariom Verma <hariom18599@gmail.com>
> Subject: Re: [PATCH v2 2/4] t5509: initialized `pushee` as bare repository

s/initialized/initialize/ at least, perhaps.

Subject: [PATCH v2 2/4] t5509: use a bare repository for test push target

may be easier to understand, though.  Then the first paragraph of
the body of the proposed message, which gives an excellent
description of how the current tests rely on a bug that we plan to
fix in a later step of the series, explains why we do not want to
push into a non-bare repository.

> `receive.denyCurrentBranch` currently has a bug where it allows pushing
> into non-bare repository using namespaces as long as it does not have any
> commits. This would cause t5509 to fail once that bug is fixed because it
> pushes into an unborn current branch.

And then you give a good description why not just it is safe, but it
makes more sense.  Very well explained.

> In t5509, no operations are performed inside `pushee`, as it is only a
> target for `git push` and `git ls-remote` calls. Therefore it does not
> need to have a worktree. So, it is safe to change `pushee` to a bare
> repository.

>
> Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> Signed-off-by: Hariom Verma <hariom18599@gmail.com>
> ---
>  t/t5509-fetch-push-namespaces.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
> index 75cbfcc392c..e3975bd21de 100755
> --- a/t/t5509-fetch-push-namespaces.sh
> +++ b/t/t5509-fetch-push-namespaces.sh
> @@ -20,7 +20,7 @@ test_expect_success setup '
>  	) &&
>  	commit0=$(cd original && git rev-parse HEAD^) &&
>  	commit1=$(cd original && git rev-parse HEAD) &&
> -	git init pushee &&
> +	git init --bare pushee &&
>  	git init puller
>  '

[PATCH v2 3/4] bug: denyCurrentBranch and unborn branch with ref namespace

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

git supports an interesting feature 'Git namespaces' that allows
dividing the refs of a single repository into multiple namespaces, each
of which has its own branches, tags, and HEAD. But unfortunately, there
exists a bug in `denyCurrentBranch` which allows pushing into a non-bare
repository using a ref namespace even if it does not have any commits

Here is a nice and short demonstration of that bug.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 t/t5509-fetch-push-namespaces.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index e3975bd21de..c89483fdba2 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -152,4 +152,13 @@ test_expect_success 'clone chooses correct HEAD (v2)' '
 	test_cmp expect actual
 '
 
+test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '
+	cd original &&
+	git init unborn &&
+	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
+	test_must_fail git push unborn-namespaced HEAD:master &&
+	test_config -C unborn receive.denyCurrentBranch updateInstead &&
+	git push unborn-namespaced HEAD:master
+'
+
 test_done
-- 
gitgitgadget

Re: [PATCH v2 3/4] bug: denyCurrentBranch and unborn branch with ref namespace

[Junio C Hamano]

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

> +test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '

Please do not chdir around in the test script.  The next person who
adds new test after this test will be surprised that his/her test
does not start at the top-level of the test/trash directory, but in
the "original" subdirectory.

And no, adding "&& cd .." at the end of this &&-cascade is *not* a
fix---when any of the steps chained with && fails, such a "we have
moved the process to a wrong place, so let's move back with 'cd ..'"
will not get executed.

> +	cd original &&
> +	git init unborn &&
> +	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
> +	test_must_fail git push unborn-namespaced HEAD:master &&
> +	test_config -C unborn receive.denyCurrentBranch updateInstead &&
> +	git push unborn-namespaced HEAD:master
> +'

What is often done to fix is to execute what you need to run in a
subshell, e.g.

	test_expect_success 'demonstration' '
		(
			cd original &&
			git init unborn &&
			...
			test_must_fail git push ... &&
			git -C unborn config ... &&
			git push ...
		)
	'

The use of "git config" instead of "test_config" in the above
illustration is deliberate---the latter does not work and should not
be used inside a subshell.

> +
>  test_done

[PATCH v2 4/4] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

The receive.denyCurrentBranch config option controls what happens if
you push to a branch that is checked out into a non-bare repository.
By default, it rejects it. It can be disabled via `ignore` or `warn`.
Another yet trickier option is `updateInstead`.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected.

With this change, all worktrees are respected.

That change also leads to revealing another bug,
i.e. `receive.denyCurrentBranch = true` was ignored when pushing into a
non-bare repository's unborn current branch using ref namespaces. As
`is_ref_checked_out()` returns 0 which means `receive-pack` does not get
into conditional statement to switch `deny_current_branch` accordingly
(ignore, warn, refuse, unconfigured, updateInstead).

receive.denyCurrentBranch uses the function `refs_resolve_ref_unsafe()`
(called via `resolve_refdup()`) to resolve the symbolic ref HEAD, but
that function fails when HEAD does not point at a valid commit.
As we replace the call to `refs_resolve_ref_unsafe()` with
`find_shared_symref()`, which has no problem finding the worktree for a
given branch even if it is unborn yet, this bug is fixed at the same
time: receive.denyCurrentBranch now also handles worktrees with unborn
branches as intended even while using ref namespaces.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 builtin/receive-pack.c           | 37 +++++++++++++++++---------------
 t/t5509-fetch-push-namespaces.sh |  2 +-
 t/t5516-fetch-push.sh            | 11 ++++++++++
 3 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 411e0b4d999..b5ca3123b78 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -27,6 +27,7 @@
 #include "object-store.h"
 #include "protocol.h"
 #include "commit-reach.h"
+#include "worktree.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
@@ -816,16 +817,6 @@ static int run_update_hook(struct command *cmd)
 	return finish_command(&proc);
 }
 
-static int is_ref_checked_out(const char *ref)
-{
-	if (is_bare_repository())
-		return 0;
-
-	if (!head_name)
-		return 0;
-	return !strcmp(head_name, ref);
-}
-
 static char *refuse_unconfigured_deny_msg =
 	N_("By default, updating the current branch in a non-bare repository\n"
 	   "is denied, because it will make the index and work tree inconsistent\n"
@@ -997,16 +988,27 @@ static const char *push_to_checkout(unsigned char *hash,
 		return NULL;
 }
 
-static const char *update_worktree(unsigned char *sha1)
+static const char *update_worktree(unsigned char *sha1, const struct worktree *worktree)
 {
-	const char *retval;
-	const char *work_tree = git_work_tree_cfg ? git_work_tree_cfg : "..";
+	const char *retval, *work_tree, *git_dir = NULL;
 	struct argv_array env = ARGV_ARRAY_INIT;
 
+	if (worktree && worktree->path)
+		work_tree = worktree->path;
+	else if (git_work_tree_cfg)
+		work_tree = git_work_tree_cfg;
+	else
+		work_tree = "..";
+
 	if (is_bare_repository())
 		return "denyCurrentBranch = updateInstead needs a worktree";
+	
+	if (worktree)
+		git_dir = get_worktree_git_dir(worktree);
+	if (!git_dir)
+		git_dir = get_git_dir();
 
-	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(get_git_dir()));
+	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(git_dir));
 
 	if (!find_hook(push_to_checkout_hook))
 		retval = push_to_deploy(sha1, &env, work_tree);
@@ -1026,6 +1028,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	struct object_id *old_oid = &cmd->old_oid;
 	struct object_id *new_oid = &cmd->new_oid;
 	int do_update_worktree = 0;
+	const struct worktree *worktree = is_bare_repository() ? NULL : find_shared_symref("HEAD", name);
 
 	/* only refs/... are allowed */
 	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
@@ -1037,7 +1040,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	free(namespaced_name);
 	namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
 
-	if (is_ref_checked_out(namespaced_name)) {
+	if (worktree) {
 		switch (deny_current_branch) {
 		case DENY_IGNORE:
 			break;
@@ -1069,7 +1072,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 			return "deletion prohibited";
 		}
 
-		if (head_name && !strcmp(namespaced_name, head_name)) {
+		if (worktree || (head_name && !strcmp(namespaced_name, head_name))) {
 			switch (deny_delete_current) {
 			case DENY_IGNORE:
 				break;
@@ -1118,7 +1121,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	}
 
 	if (do_update_worktree) {
-		ret = update_worktree(new_oid->hash);
+		ret = update_worktree(new_oid->hash, find_shared_symref("HEAD", name));
 		if (ret)
 			return ret;
 	}
diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index c89483fdba2..6270fb7b576 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -152,7 +152,7 @@ test_expect_success 'clone chooses correct HEAD (v2)' '
 	test_cmp expect actual
 '
 
-test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '
+test_expect_success 'denyCurrentBranch and unborn branch with ref namespace' '
 	cd original &&
 	git init unborn &&
 	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index c81ca360ac4..49982b0fd90 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1712,4 +1712,15 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
 	)
 '
 
+test_expect_success 'denyCurrentBranch and worktrees' '
+	git worktree add new-wt &&
+	git clone . cloned &&
+	test_commit -C cloned first &&
+	test_config receive.denyCurrentBranch refuse &&
+	test_must_fail git -C cloned push origin HEAD:new-wt &&
+	test_config receive.denyCurrentBranch updateInstead &&
+	git -C cloned push origin HEAD:new-wt &&
+	test_must_fail git -C cloned push --delete origin new-wt
+'
+
 test_done
-- 
gitgitgadget

Re: [PATCH v2 4/4] receive.denyCurrentBranch: respect all worktrees

[Junio C Hamano]

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

> diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
> index c89483fdba2..6270fb7b576 100755
> --- a/t/t5509-fetch-push-namespaces.sh
> +++ b/t/t5509-fetch-push-namespaces.sh
> @@ -152,7 +152,7 @@ test_expect_success 'clone chooses correct HEAD (v2)' '
>  	test_cmp expect actual
>  '
>  
> -test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '
> +test_expect_success 'denyCurrentBranch and unborn branch with ref namespace' '
>  	cd original &&
>  	git init unborn &&
>  	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
> diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
> index c81ca360ac4..49982b0fd90 100755
> --- a/t/t5516-fetch-push.sh
> +++ b/t/t5516-fetch-push.sh
> @@ -1712,4 +1712,15 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
>  	)
>  '
>  
> +test_expect_success 'denyCurrentBranch and worktrees' '
> +	git worktree add new-wt &&
> +	git clone . cloned &&
> +	test_commit -C cloned first &&
> +	test_config receive.denyCurrentBranch refuse &&
> +	test_must_fail git -C cloned push origin HEAD:new-wt &&
> +	test_config receive.denyCurrentBranch updateInstead &&
> +	git -C cloned push origin HEAD:new-wt &&
> +	test_must_fail git -C cloned push --delete origin new-wt
> +'
> +
>  test_done

This adds one new test and also flips a test that was added in a
separate step that expected a failure to expect success, which looks
a bit strange.

For a series this small, having a test that demonstrates that the
updated code works as expected together with the fix to the code in
a single patch is easier to manage.  After applying a single
test+fix patch, you can easily apply the same patch except for the
test part in reverse on top, if you need to see in what way the code
without the change breaks by running the test.

On a truly large fix, sometimes it may make sense to add a failing
test and nothing else and then a separate step that changes the code
and flips the expectation of the test from failure->success, but I
think a change this size is easier to handle without such an artificial
split.

Thanks.

[PATCH v3 0/3] [GSoC] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

The receive.denyCurrentBranch config option controls what happens if you
push to a branch that is checkout into a non-bare repository. By default, it
rejects it. It can be disabled via ignore or warn. Another yet trickier
option is updateInstead.

When receive.denyCurrentBranch is set to updateInstead, a push that tries to
update the branch that is currently checked out is accepted only when the
index and the working tree exactly matches the currently checked out commit,
in which case the index and the working tree are updated to match the pushed
commit. Otherwise, the push is refused.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected. [ fixes:
#331 ]

Incidently, this change also fixes another bug i.e. 
receive.denyCurrentBranch = true was ignored when pushing into a non-bare
repository using ref namespaces.

Thanks, @dscho for helping me out.

Regards, Hariom

Hariom Verma (3):
  get_main_worktree(): allow it to be called in the Git directory
  t5509: use a bare repository for test push target
  receive.denyCurrentBranch: respect all worktrees

 builtin/receive-pack.c           | 37 +++++++++++++++++---------------
 t/t5509-fetch-push-namespaces.sh | 13 ++++++++++-
 t/t5516-fetch-push.sh            | 11 ++++++++++
 worktree.c                       |  1 +
 4 files changed, 44 insertions(+), 18 deletions(-)


base-commit: 232378479ee6c66206d47a9be175e3a39682aea6
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-535%2Fharry-hov%2Fdeny-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-535/harry-hov/deny-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/535

Range-diff vs v2:

 1:  8718facbc95 = 1:  8718facbc95 get_main_worktree(): allow it to be called in the Git directory
 2:  5c749e044a3 ! 2:  ae749310f06 t5509: initialized `pushee` as bare repository
     @@ -1,6 +1,6 @@
      Author: Hariom Verma <hariom18599@gmail.com>
      
     -    t5509: initialized `pushee` as bare repository
     +    t5509: use a bare repository for test push target
      
          `receive.denyCurrentBranch` currently has a bug where it allows pushing
          into non-bare repository using namespaces as long as it does not have any
 3:  b3e573d44a9 < -:  ----------- bug: denyCurrentBranch and unborn branch with ref namespace
 4:  61e5f75a6f9 ! 3:  d21a590d6c2 receive.denyCurrentBranch: respect all worktrees
     @@ -134,11 +134,18 @@
       	test_cmp expect actual
       '
       
     --test_expect_failure 'denyCurrentBranch and unborn branch with ref namespace' '
      +test_expect_success 'denyCurrentBranch and unborn branch with ref namespace' '
     - 	cd original &&
     - 	git init unborn &&
     - 	git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
     ++	(
     ++		cd original &&
     ++		git init unborn &&
     ++		git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
     ++		test_must_fail git push unborn-namespaced HEAD:master &&
     ++		git -C unborn config receive.denyCurrentBranch updateInstead &&
     ++		git push unborn-namespaced HEAD:master
     ++	)
     ++'
     ++
     + test_done
      
       diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
       --- a/t/t5516-fetch-push.sh

-- 
gitgitgadget

[PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

When called in the Git directory of a non-bare repository, this function
would not return the directory of the main worktree, but of the Git
directory instead.

The reason: when the Git directory is the current working directory, the
absolute path of the common directory will be reported with a trailing
`/.git/.`, which the code of `get_main_worktree()` does not handle
correctly.

Let's fix this.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 worktree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/worktree.c b/worktree.c
index 5b4793caa34..7c8cd213171 100644
--- a/worktree.c
+++ b/worktree.c
@@ -51,6 +51,7 @@ static struct worktree *get_main_worktree(void)
 	struct strbuf worktree_path = STRBUF_INIT;
 
 	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	strbuf_strip_suffix(&worktree_path, "/.");
 	if (!strbuf_strip_suffix(&worktree_path, "/.git"))
 		strbuf_strip_suffix(&worktree_path, "/.");
 
-- 
gitgitgadget

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Eric Sunshine]

On Sun, Feb 23, 2020 at 1:57 PM Hariom Verma via GitGitGadget
<gitgitgadget@gmail.com> wrote:
> get_main_worktree(): allow it to be called in the Git directory

This title is a bit too generic; it fails to explain what this patch
is really fixing. Perhaps:

    get_main_worktree: correctly normalize worktree path when in .git dir

or something.

> When called in the Git directory of a non-bare repository, this function
> would not return the directory of the main worktree, but of the Git
> directory instead.

"Git directory" is imprecise. As a reader, I can't tell if this means
the main worktree into which the project is checked out or the `.git`
directory itself. Please write it instead as "`.git` directory".

> The reason: when the Git directory is the current working directory, the
> absolute path of the common directory will be reported with a trailing
> `/.git/.`, which the code of `get_main_worktree()` does not handle
> correctly.
>
> Signed-off-by: Hariom Verma <hariom18599@gmail.com>
> ---
> diff --git a/worktree.c b/worktree.c
> @@ -51,6 +51,7 @@ static struct worktree *get_main_worktree(void)
>         strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
> +       strbuf_strip_suffix(&worktree_path, "/.");
>         if (!strbuf_strip_suffix(&worktree_path, "/.git"))
>                 strbuf_strip_suffix(&worktree_path, "/.");

This change makes the code unnecessarily confusing and effectively
turns the final line into dead code. I would much rather see the three
cases spelled out explicitly, perhaps like this:

    if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
        !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
            strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */

Also, please add a test to ensure that this behavior doesn't regress
in the future. You can probably test it via the "git worktree list"
command, so perhaps add the test to t/t2402-worktree-list.sh.

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Hariom verma]

Hi Eric,

On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
>
> This title is a bit too generic; it fails to explain what this patch
> is really fixing. Perhaps:
>
>     get_main_worktree: correctly normalize worktree path when in .git dir
>
> or something.
>
> "Git directory" is imprecise. As a reader, I can't tell if this means
> the main worktree into which the project is checked out or the `.git`
> directory itself. Please write it instead as "`.git` directory".
> [...]
> This change makes the code unnecessarily confusing and effectively
> turns the final line into dead code. I would much rather see the three
> cases spelled out explicitly, perhaps like this:
>
>     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
>         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
>             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */

I'll implement these comments in the next revision for sure.

> Also, please add a test to ensure that this behavior doesn't regress
> in the future. You can probably test it via the "git worktree list"
> command, so perhaps add the test to t/t2402-worktree-list.sh.

There already exists tests in "t/t2402-worktree-list.sh" which lists and
verifies all worktrees. Does this make sense to write a new test that
also does kinda the same thing?

Thanks,
Hariom

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Eric Sunshine]

On Mon, Feb 24, 2020 at 6:09 AM Hariom verma <hariom18599@gmail.com> wrote:
> On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> >     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
> >         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
> >             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */
> >
> > Also, please add a test to ensure that this behavior doesn't regress
> > in the future. You can probably test it via the "git worktree list"
> > command, so perhaps add the test to t/t2402-worktree-list.sh.
>
> There already exists tests in "t/t2402-worktree-list.sh" which lists and
> verifies all worktrees. Does this make sense to write a new test that
> also does kinda the same thing?

The change this patch is making is to correctly strip the suffix
"/.git/." from the main worktree's path since that suffix was not
getting stripped correctly by the existing code. We want a test that
verifies that the "/.git/." suffix is indeed being stripped once this
change is applied. If there is an existing test which already checks
the output of "git worktree list" when invoked from within the .git
directory, then that test should suffice, but then I would have
expected that you would have had to tweak the existing test to make it
succeed after this change. If there is no such test which verifies
that "/.git/." is being stripped, then this patch should add one. "git
worktree list" would be a possible way to implement such a test.

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Johannes Schindelin]

Hi,

On Mon, 24 Feb 2020, Hariom verma wrote:

> On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> >
> > This title is a bit too generic; it fails to explain what this patch
> > is really fixing. Perhaps:
> >
> >     get_main_worktree: correctly normalize worktree path when in .git dir
> >
> > or something.
> >
> > "Git directory" is imprecise. As a reader, I can't tell if this means
> > the main worktree into which the project is checked out or the `.git`
> > directory itself. Please write it instead as "`.git` directory".
> > [...]
> > This change makes the code unnecessarily confusing and effectively
> > turns the final line into dead code. I would much rather see the three
> > cases spelled out explicitly, perhaps like this:
> >
> >     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
> >         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
> >             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */

I would be really cautious about that.

To me, the originally proposed change says: strip `/.`, if any. Then,
strip `/.git`, and if successful, strip another `/.`, if any.

That reads pretty fine to me. It makes sense.

Above-mentioned proposal, however, puts quite a few twists into my brain,
as is a "if neither X nor Y then Z", and I find the code comments outright
confusing.

> I'll implement these comments in the next revision for sure.

I'd like to suggest taking a step back and reflecting whether _you_ like
the suggested version better. It is just a suggestion, after all, and if
it was up to me, I would argue against it.

> > Also, please add a test to ensure that this behavior doesn't regress
> > in the future. You can probably test it via the "git worktree list"
> > command, so perhaps add the test to t/t2402-worktree-list.sh.
>
> There already exists tests in "t/t2402-worktree-list.sh" which lists and
> verifies all worktrees. Does this make sense to write a new test that
> also does kinda the same thing?

The scenario in which we found the buggy behavior involved calling
`find_shared_symref()`. I imagine that we could use `git branch -D` inside
the `.git` directory for the new regression test.

But yes, in my testing, `git worktree list` and `git -C .git worktree
list` do show a different top-level directory (the latter shows an
incorrect one). Such a test case would find a splendid home in t2402.

Ciao,
Dscho

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Eric Sunshine]

On Mon, Feb 24, 2020 at 1:58 PM Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
> > On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> > > This change makes the code unnecessarily confusing and effectively
> > > turns the final line into dead code. I would much rather see the three
> > > cases spelled out explicitly, perhaps like this:
> > >
> > >     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
> > >         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
> > >             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */
>
> I would be really cautious about that.
>
> To me, the originally proposed change says: strip `/.`, if any. Then,
> strip `/.git`, and if successful, strip another `/.`, if any.

That's not at all what the original said, which is reproduced here:

    if (!strbuf_strip_suffix(&worktree_path, "/.git"))
        strbuf_strip_suffix(&worktree_path, "/.");

It says "try stripping '/.git'; if that fails, try stripping '/.'".
That is, it recognizes and handles two distinct cases: (1) the path to
the .git directory of a non-bare repository, which always ends with
"/.git", and (2) the path to a bare git repository, which always ends
with "/.". So, the original code wasn't doing any sort of incremental
stripping of suffixes; it was just handling two known distinct cases.

Perhaps you missed the '!' in the conditional?

> That reads pretty fine to me. It makes sense.

To me, it doesn't make sense to update the code as done by the patch
since that just muddies the issue by making it seem as if
get_git_common_dir() is indeterminately tacking on various suffixes
rather than giving us deterministic results.

> Above-mentioned proposal, however, puts quite a few twists into my brain,
> as is a "if neither X nor Y then Z", and I find the code comments outright
> confusing.

It's just three distinct cases my proposed code is handling; there are
no twists.

> The scenario in which we found the buggy behavior involved calling
> `find_shared_symref()`. I imagine that we could use `git branch -D` inside
> the `.git` directory for the new regression test.
>
> But yes, in my testing, `git worktree list` and `git -C .git worktree
> list` do show a different top-level directory (the latter shows an
> incorrect one). Such a test case would find a splendid home in t2402.

I don't have strong feelings about how it is tested, but would like to
see some sort of test proving that it works as expected following this
change.

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Johannes Schindelin]

Hi Eric,

On Mon, 24 Feb 2020, Eric Sunshine wrote:

> On Mon, Feb 24, 2020 at 1:58 PM Johannes Schindelin
> <Johannes.Schindelin@gmx.de> wrote:
> > > On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> > > > This change makes the code unnecessarily confusing and effectively
> > > > turns the final line into dead code. I would much rather see the three
> > > > cases spelled out explicitly, perhaps like this:
> > > >
> > > >     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
> > > >         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
> > > >             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */
> >
> > I would be really cautious about that.
> >
> > To me, the originally proposed change says: strip `/.`, if any. Then,
> > strip `/.git`, and if successful, strip another `/.`, if any.
>
> That's not at all what the original said, which is reproduced here:
>
>     if (!strbuf_strip_suffix(&worktree_path, "/.git"))
>         strbuf_strip_suffix(&worktree_path, "/.");
>
> It says "try stripping '/.git'; if that fails, try stripping '/.'".
> That is, it recognizes and handles two distinct cases: (1) the path to
> the .git directory of a non-bare repository, which always ends with
> "/.git", and (2) the path to a bare git repository, which always ends
> with "/.". So, the original code wasn't doing any sort of incremental
> stripping of suffixes; it was just handling two known distinct cases.
>
> Perhaps you missed the '!' in the conditional?

I totally did. Sorry!

Ciao,
Dscho

Re: [PATCH v3 1/3] get_main_worktree(): allow it to be called in the Git directory

[Junio C Hamano]

Hariom verma <hariom18599@gmail.com> writes:

> Hi Eric,
>
> On Mon, Feb 24, 2020 at 7:12 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
>>
>> This title is a bit too generic; it fails to explain what this patch
>> is really fixing. Perhaps:
>>
>>     get_main_worktree: correctly normalize worktree path when in .git dir
>>
>> or something.
>>
>> "Git directory" is imprecise. As a reader, I can't tell if this means
>> the main worktree into which the project is checked out or the `.git`
>> directory itself. Please write it instead as "`.git` directory".
>> [...]
>> This change makes the code unnecessarily confusing and effectively
>> turns the final line into dead code. I would much rather see the three
>> cases spelled out explicitly, perhaps like this:
>>
>>     if (!strbuf_strip_suffix(&worktree_path, "/.git/.") && /* in .git dir */
>>         !strbuf_strip_suffix(&worktree_path, "/.git/")) /* in worktree */
>>             strbuf_strip_suffix(&worktree_path, "/."); /* in bare repo */
>
> I'll implement these comments in the next revision for sure.
>
>> Also, please add a test to ensure that this behavior doesn't regress
>> in the future. You can probably test it via the "git worktree list"
>> command, so perhaps add the test to t/t2402-worktree-list.sh.
>
> There already exists tests in "t/t2402-worktree-list.sh" which lists and
> verifies all worktrees. Does this make sense to write a new test that
> also does kinda the same thing?

I'd read Eric's suggestion as "please make sure we have a test to
ensure...".  If there already are tests that protects the behaviour
we care about here, there is no need to duplicate it.

Thanks for working on this topic.

[PATCH v3 2/3] t5509: use a bare repository for test push target

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

`receive.denyCurrentBranch` currently has a bug where it allows pushing
into non-bare repository using namespaces as long as it does not have any
commits. This would cause t5509 to fail once that bug is fixed because it
pushes into an unborn current branch.

In t5509, no operations are performed inside `pushee`, as it is only a
target for `git push` and `git ls-remote` calls. Therefore it does not
need to have a worktree. So, it is safe to change `pushee` to a bare
repository.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 t/t5509-fetch-push-namespaces.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index 75cbfcc392c..e3975bd21de 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -20,7 +20,7 @@ test_expect_success setup '
 	) &&
 	commit0=$(cd original && git rev-parse HEAD^) &&
 	commit1=$(cd original && git rev-parse HEAD) &&
-	git init pushee &&
+	git init --bare pushee &&
 	git init puller
 '
 
-- 
gitgitgadget

[PATCH v3 3/3] receive.denyCurrentBranch: respect all worktrees

[Hariom Verma via GitGitGadget]

From: Hariom Verma <hariom18599@gmail.com>

The receive.denyCurrentBranch config option controls what happens if
you push to a branch that is checked out into a non-bare repository.
By default, it rejects it. It can be disabled via `ignore` or `warn`.
Another yet trickier option is `updateInstead`.

However, this setting was forgotten when the git worktree command was
introduced: only the main worktree's current branch is respected.

With this change, all worktrees are respected.

That change also leads to revealing another bug,
i.e. `receive.denyCurrentBranch = true` was ignored when pushing into a
non-bare repository's unborn current branch using ref namespaces. As
`is_ref_checked_out()` returns 0 which means `receive-pack` does not get
into conditional statement to switch `deny_current_branch` accordingly
(ignore, warn, refuse, unconfigured, updateInstead).

receive.denyCurrentBranch uses the function `refs_resolve_ref_unsafe()`
(called via `resolve_refdup()`) to resolve the symbolic ref HEAD, but
that function fails when HEAD does not point at a valid commit.
As we replace the call to `refs_resolve_ref_unsafe()` with
`find_shared_symref()`, which has no problem finding the worktree for a
given branch even if it is unborn yet, this bug is fixed at the same
time: receive.denyCurrentBranch now also handles worktrees with unborn
branches as intended even while using ref namespaces.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
---
 builtin/receive-pack.c           | 37 +++++++++++++++++---------------
 t/t5509-fetch-push-namespaces.sh | 11 ++++++++++
 t/t5516-fetch-push.sh            | 11 ++++++++++
 3 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 411e0b4d999..b5ca3123b78 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -27,6 +27,7 @@
 #include "object-store.h"
 #include "protocol.h"
 #include "commit-reach.h"
+#include "worktree.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),
@@ -816,16 +817,6 @@ static int run_update_hook(struct command *cmd)
 	return finish_command(&proc);
 }
 
-static int is_ref_checked_out(const char *ref)
-{
-	if (is_bare_repository())
-		return 0;
-
-	if (!head_name)
-		return 0;
-	return !strcmp(head_name, ref);
-}
-
 static char *refuse_unconfigured_deny_msg =
 	N_("By default, updating the current branch in a non-bare repository\n"
 	   "is denied, because it will make the index and work tree inconsistent\n"
@@ -997,16 +988,27 @@ static const char *push_to_checkout(unsigned char *hash,
 		return NULL;
 }
 
-static const char *update_worktree(unsigned char *sha1)
+static const char *update_worktree(unsigned char *sha1, const struct worktree *worktree)
 {
-	const char *retval;
-	const char *work_tree = git_work_tree_cfg ? git_work_tree_cfg : "..";
+	const char *retval, *work_tree, *git_dir = NULL;
 	struct argv_array env = ARGV_ARRAY_INIT;
 
+	if (worktree && worktree->path)
+		work_tree = worktree->path;
+	else if (git_work_tree_cfg)
+		work_tree = git_work_tree_cfg;
+	else
+		work_tree = "..";
+
 	if (is_bare_repository())
 		return "denyCurrentBranch = updateInstead needs a worktree";
+	
+	if (worktree)
+		git_dir = get_worktree_git_dir(worktree);
+	if (!git_dir)
+		git_dir = get_git_dir();
 
-	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(get_git_dir()));
+	argv_array_pushf(&env, "GIT_DIR=%s", absolute_path(git_dir));
 
 	if (!find_hook(push_to_checkout_hook))
 		retval = push_to_deploy(sha1, &env, work_tree);
@@ -1026,6 +1028,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	struct object_id *old_oid = &cmd->old_oid;
 	struct object_id *new_oid = &cmd->new_oid;
 	int do_update_worktree = 0;
+	const struct worktree *worktree = is_bare_repository() ? NULL : find_shared_symref("HEAD", name);
 
 	/* only refs/... are allowed */
 	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
@@ -1037,7 +1040,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	free(namespaced_name);
 	namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
 
-	if (is_ref_checked_out(namespaced_name)) {
+	if (worktree) {
 		switch (deny_current_branch) {
 		case DENY_IGNORE:
 			break;
@@ -1069,7 +1072,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 			return "deletion prohibited";
 		}
 
-		if (head_name && !strcmp(namespaced_name, head_name)) {
+		if (worktree || (head_name && !strcmp(namespaced_name, head_name))) {
 			switch (deny_delete_current) {
 			case DENY_IGNORE:
 				break;
@@ -1118,7 +1121,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
 	}
 
 	if (do_update_worktree) {
-		ret = update_worktree(new_oid->hash);
+		ret = update_worktree(new_oid->hash, find_shared_symref("HEAD", name));
 		if (ret)
 			return ret;
 	}
diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh
index e3975bd21de..a67f792adf4 100755
--- a/t/t5509-fetch-push-namespaces.sh
+++ b/t/t5509-fetch-push-namespaces.sh
@@ -152,4 +152,15 @@ test_expect_success 'clone chooses correct HEAD (v2)' '
 	test_cmp expect actual
 '
 
+test_expect_success 'denyCurrentBranch and unborn branch with ref namespace' '
+	(
+		cd original &&
+		git init unborn &&
+		git remote add unborn-namespaced "ext::git --namespace=namespace %s unborn" &&
+		test_must_fail git push unborn-namespaced HEAD:master &&
+		git -C unborn config receive.denyCurrentBranch updateInstead &&
+		git push unborn-namespaced HEAD:master
+	)
+'
+
 test_done
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index c81ca360ac4..49982b0fd90 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1712,4 +1712,15 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
 	)
 '
 
+test_expect_success 'denyCurrentBranch and worktrees' '
+	git worktree add new-wt &&
+	git clone . cloned &&
+	test_commit -C cloned first &&
+	test_config receive.denyCurrentBranch refuse &&
+	test_must_fail git -C cloned push origin HEAD:new-wt &&
+	test_config receive.denyCurrentBranch updateInstead &&
+	git -C cloned push origin HEAD:new-wt &&
+	test_must_fail git -C cloned push --delete origin new-wt
+'
+
 test_done
-- 
gitgitgadget