[PATCH 0/2] Fix a couple of minor rebase -i regressions

From: Phillip Wood <redacted>

These patches fix a regression in the reflog message written when
rebase -i finishes and supresses the status output from applying any
autostashed changes to match the shell version of rebase -i.

Phillip Wood (2):
  rebase -i: fix reflog message
  rebase -i: silence stash apply

 sequencer.c | 3 +++
 1 file changed, 3 insertions(+)

-- 
2.13.0

From: Phillip Wood <redacted>

When rebase -i was converted to C a bug was introduced into the code
that creates the reflog message. Instead of saying
rebase -i (finish): <head-name> onto <onto>
it says
rebase -i (finish): <head-name> onto <orig-head><onto>
as the strbuf is not reset between reading the value of <orig-head>
and <onto>.

Signed-off-by: Phillip Wood <redacted>
---
 sequencer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sequencer.c b/sequencer.c
index 0fa3fb14f7c1df5f11ba0ef7e4e46a44a32817bd..f8bc18badf1a3fb1b39656501c5a316e229968d2 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -2089,6 +2089,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 				res = error(_("could not read orig-head"));
 				goto cleanup_head_ref;
 			}
+			strbuf_reset(&buf);
 			if (!read_oneliner(&buf, rebase_path_onto(), 0)) {
 				res = error(_("could not read 'onto'"));
 				goto cleanup_head_ref;

-- 
2.13.0

From: Phillip Wood <redacted>

The shell version of rebase -i silences the status output from 'git
stash apply' when restoring the autostashed changes. The C version
does not.

Having the output from git stash apply on the screen is
distracting as it makes it difficult to find the message from git
rebase saying that the rebase succeeded. Also the status information
that git stash prints talks about looking in .git/rebase-merge/done to
see which commits have been applied. As .git/rebase-merge is removed
shortly after the message is printed before rebase -i exits this is
confusing.

Signed-off-by: Phillip Wood <redacted>
---
 sequencer.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sequencer.c b/sequencer.c
index f8bc18badf1a3fb1b39656501c5a316e229968d2..311728a145dfc66e230334221a2610468239932d 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -1914,6 +1914,8 @@ static int apply_autostash(struct replay_opts *opts)
 	strbuf_trim(&stash_sha1);
 
 	child.git_cmd = 1;
+	child.no_stdout = 1;
+	child.no_stderr = 1;
 	argv_array_push(&child.args, "stash");
 	argv_array_push(&child.args, "apply");
 	argv_array_push(&child.args, stash_sha1.buf);

-- 
2.13.0

Hi Phillip,

On Thu, 18 May 2017, Phillip Wood wrote:

If I remember correctly, then the shell version prints the output in case
of an error.

We already imitated that behavior in `git commit`
(https://github.com/git-for-windows/git/blob/v2.13.0.windows.1/sequencer.c#L674-L684):

		/* hide stderr on success */
		struct strbuf buf = STRBUF_INIT;
		int rc = pipe_command(&cmd,
				      NULL, 0,
				      /* stdout is already redirected */
				      NULL, 0,
				      &buf, 0);
		if (rc)
			fputs(buf.buf, stderr);
		strbuf_release(&buf);

I think that would be the appropriate approach here, too.

Ciao,
Johannes

P.S.: it may be a very good idea to accompany this patch (as well as the
previous one) by a patch to the test suite to verify that the fixed code
does not regress.

Hi Johannes

Thanks for your reply
On 18/05/17 11:49, Johannes Schindelin wrote:

Hi Phillip,

On Thu, 18 May 2017, Phillip Wood wrote:

quoted

diff --git a/sequencer.c b/sequencer.c
index f8bc18badf1a3fb1b39656501c5a316e229968d2..311728a145dfc66e230334221a2610468239932d 100644
--- a/sequencer.c
+++ b/sequencer.c

@@ -1914,6 +1914,8 @@ static int apply_autostash(struct replay_opts *opts)
  	strbuf_trim(&stash_sha1);
  
  	child.git_cmd = 1;
+	child.no_stdout = 1;
+	child.no_stderr = 1;
  	argv_array_push(&child.args, "stash");
  	argv_array_push(&child.args, "apply");
  	argv_array_push(&child.args, stash_sha1.buf);

If I remember correctly, then the shell version prints the output in case
of an error.

The shell version prints it's own error message if there's an error, the C version does this as well

Shell version:
apply_autostash () {
	if test -f "$state_dir/autostash"
	then
		stash_sha1=$(cat "$state_dir/autostash")
		if git stash apply $stash_sha1 2>&1 >/dev/null
		then
			echo "$(gettext 'Applied autostash.')"
		else
			git stash store -m "autostash" -q $stash_sha1 ||
			die "$(eval_gettext "Cannot store \$stash_sha1")"
			gettext 'Applying autostash resulted in conflicts.
Your changes are safe in the stash.
You can run "git stash pop" or "git stash drop" at any time.
'
		fi
	fi
}

C version:
static int apply_autostash(struct replay_opts *opts)
{
	struct strbuf stash_sha1 = STRBUF_INIT;
	struct child_process child = CHILD_PROCESS_INIT;
	int ret = 0;

	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
		strbuf_release(&stash_sha1);
		return 0;
	}
	strbuf_trim(&stash_sha1);

	child.git_cmd = 1;
	child.no_stdout = 1;
	child.no_stderr = 1;
	argv_array_push(&child.args, "stash");
	argv_array_push(&child.args, "apply");
	argv_array_push(&child.args, stash_sha1.buf);
	if (!run_command(&child))
		printf(_("Applied autostash.\n"));
	else {
		struct child_process store = CHILD_PROCESS_INIT;

		store.git_cmd = 1;
		argv_array_push(&store.args, "stash");
		argv_array_push(&store.args, "store");
		argv_array_push(&store.args, "-m");
		argv_array_push(&store.args, "autostash");
		argv_array_push(&store.args, "-q");
		argv_array_push(&store.args, stash_sha1.buf);
		if (run_command(&store))
			ret = error(_("cannot store %s"), stash_sha1.buf);
		else
			printf(_("Applying autostash resulted in conflicts.\n"
				"Your changes are safe in the stash.\n"
				"You can run \"git stash pop\" or"
				" \"git stash drop\" at any time.\n"));
	}

	strbuf_release(&stash_sha1);
	return ret;
}

We already imitated that behavior in `git commit`
(https://github.com/git-for-windows/git/blob/v2.13.0.windows.1/sequencer.c#L674-L684):

		/* hide stderr on success */
		struct strbuf buf = STRBUF_INIT;
		int rc = pipe_command(&cmd,
				      NULL, 0,
				      /* stdout is already redirected */
				      NULL, 0,
				      &buf, 0);
		if (rc)
			fputs(buf.buf, stderr);
		strbuf_release(&buf);

I think that would be the appropriate approach here, too.

I can change it to do this if you think it is an improvement but the existing error message seems fairly clear to me and I think (though I haven't checked) that the call to stash store should print out the id of the stash for the user

P.S.: it may be a very good idea to accompany this patch (as well as the
previous one) by a patch to the test suite to verify that the fixed code
does not regress.

I agree that a test for this (and probably my other changes) would be useful, I'll try and put something together but it won't be until after the end of next week.

Thanks

Phillip

Hi Phillip,

On Thu, 18 May 2017, Phillip Wood wrote:

The shell version prints it's own error message if there's an error, the
C version does this as well

Shell version:
apply_autostash () {
	if test -f "$state_dir/autostash"
	then
		stash_sha1=$(cat "$state_dir/autostash")
		if git stash apply $stash_sha1 2>&1 >/dev/null
		then
			echo "$(gettext 'Applied autostash.')"
		else
			git stash store -m "autostash" -q $stash_sha1 ||
			die "$(eval_gettext "Cannot store \$stash_sha1")"
			gettext 'Applying autostash resulted in conflicts.
Your changes are safe in the stash.
You can run "git stash pop" or "git stash drop" at any time.
'
		fi
	fi
}

C version:
static int apply_autostash(struct replay_opts *opts)
{
	struct strbuf stash_sha1 = STRBUF_INIT;
	struct child_process child = CHILD_PROCESS_INIT;
	int ret = 0;

	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
		strbuf_release(&stash_sha1);
		return 0;
	}
	strbuf_trim(&stash_sha1);

	child.git_cmd = 1;
	child.no_stdout = 1;
	child.no_stderr = 1;
	argv_array_push(&child.args, "stash");
	argv_array_push(&child.args, "apply");
	argv_array_push(&child.args, stash_sha1.buf);
	if (!run_command(&child))
		printf(_("Applied autostash.\n"));
	else {
		struct child_process store = CHILD_PROCESS_INIT;

		store.git_cmd = 1;
		argv_array_push(&store.args, "stash");
		argv_array_push(&store.args, "store");
		argv_array_push(&store.args, "-m");
		argv_array_push(&store.args, "autostash");
		argv_array_push(&store.args, "-q");
		argv_array_push(&store.args, stash_sha1.buf);
		if (run_command(&store))
			ret = error(_("cannot store %s"), stash_sha1.buf);
		else
			printf(_("Applying autostash resulted in conflicts.\n"
				"Your changes are safe in the stash.\n"
				"You can run \"git stash pop\" or"
				" \"git stash drop\" at any time.\n"));
	}

	strbuf_release(&stash_sha1);
	return ret;
}

Oh, you're right, I misremembered.

Thank you for being so thorough. This patch is Acked-by: me, then.

Thanks,
Johannes