diff mbox series

[v12,4/8] remote set-head: better output for --auto

Message ID 20241023153736.257733-5-bence@ferdinandy.com (mailing list archive)
State New
Headers show
Series set-head/fetch remote/HEAD updates | expand

Commit Message

Bence Ferdinandy Oct. 23, 2024, 3:36 p.m. UTC
Currently, set-head --auto will print a message saying "remote/HEAD set
to branch", which implies something was changed.

Change the output of --auto, so the output actually reflects what was
done: a) set a previously unset HEAD, b) change HEAD because remote
changed or c) no updates. As a fourth output, if HEAD is changed from
a previous value that was not a remote branch, explicitly call attention
to this fact.

Signed-off-by: Bence Ferdinandy <bence@ferdinandy.com>
---

Notes:
    v1-v2:
    
        was RFC in https://lore.kernel.org/git/20240910203835.2288291-1-bence@ferdinandy.com/
    
    v3:
    
        This patch was originally sent along when I thought set-head was
        going to be invoked by fetch, but the discussion on the RFC
        concluded that it should be not. This opened the possibility to make
        it more explicit.
    
        Note: although I feel both things the patch does are really just
        cosmetic, an argument could be made for breaking it into two, one
        for the no-op part and one for the --auto print update.
    
        Was sent in:
        https://lore.kernel.org/git/20240915221055.904107-1-bence@ferdinandy.com/
    
    v4:
        - changes are now handled atomically via the ref update transaction
        - outputs have changed along the lines of Junio's suggestion
        - minor refactor to set_head for improved legibility
    
    v5: - the minor refactor has been split out into its own patch
    
    v6: - fixed uninitialized prev_head
        - fixed case of unusual previous target
        - fixed a test that would have been actually broken at this patch
          (the output was only correct with the later update to fetch)
        - added 4 tests for the 4 output cases
    
    v7: - change commit prefix to be more in line with project standards
        - fixed tests to also work with the reftable backend
        - renamed report function, fixed style issue with checking buf len
        - fixed not releasing an strbuf
    
    v8: no change
    
    v9: - mark output strings in report_set_head_auto as translatable
        - rename buf_prev to b_local_head for consistency
        - use ${SQ} in tests instead of '\''
    
    v10: no change
    
    v11: no change
    
    v12: no change

 builtin/remote.c  | 33 +++++++++++++++++++++++++++---
 t/t5505-remote.sh | 51 ++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 4 deletions(-)

Comments

Junio C Hamano Nov. 15, 2024, 5:50 a.m. UTC | #1
Bence Ferdinandy <bence@ferdinandy.com> writes:

> Currently, set-head --auto will print a message saying "remote/HEAD set
> to branch", which implies something was changed.
>
> Change the output of --auto, so the output actually reflects what was
> done: a) set a previously unset HEAD, b) change HEAD because remote
> changed or c) no updates. As a fourth output, if HEAD is changed from
> a previous value that was not a remote branch, explicitly call attention
> to this fact.

OK.  That's sensible.

There is a slight variant of the fourth case.  HEAD may have been a
symbolic ref that pointed at an unexpected place (which you
addressed), or HEAD may have been a non-symbolic ref (which the new
code would mistakenly say "HEAD is now created", if I am reading the
patch correctly).

> diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
> index 9b50276646..0ea86d51a4 100755
> --- a/t/t5505-remote.sh
> +++ b/t/t5505-remote.sh
> @@ -432,12 +432,51 @@ test_expect_success 'set-head --auto' '
>  	)
>  '
>  
> +test_expect_success 'set-head --auto detects creation' '
> +	(
> +		cd test &&
> +		git symbolic-ref -d refs/remotes/origin/HEAD &&

Are we sure refs/remotes/origin/HEAD exists at this point in the
test, regardless of which earlier tests were skipped or failed?  If
not, perhaps

		git update-ref --no-deref -d refs/remotes/origin/HEAD &&

is a better alternative.

> +		git remote set-head --auto origin >output &&
> +		echo "${SQ}origin/HEAD${SQ} is now created and points to ${SQ}main${SQ}" >expect &&
> +		test_cmp expect output
> +	)
> +'

Here, we could insert another one:

test_expect_success 'set-head --auto to update a non symbolic ref' '
	(
		cd test &&
		git update-ref --no-deref -d refs/remotes/origin/HEAD &&
		git update-ref refs/remotes/origin/HEAD HEAD &&
		git remote set-head --auto origin >output &&

I'd imagine "output" should at least say that we are setting up a
symref origin/HEAD to point at some ref the --auto option figured
out, and if we wanted to report its previous state, it was a non
symbolic ref that pointed at some commit.  In any case,

		echo "${SQ}origin/HEAD${SQ} is now created and points to ${SQ}main${SQ}" >expect &&

is not what we want to see here, I suspect.

Can we detect the case where we overwrite a non symref with a symref
without going back to step 2/8 and doing a major surgery?

		test_cmp expect output
	)
'
diff mbox series

Patch

diff --git a/builtin/remote.c b/builtin/remote.c
index 1d68c5b2ba..108f1271d3 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -1399,10 +1399,35 @@  static int show(int argc, const char **argv, const char *prefix)
 	return result;
 }
 
+static void report_set_head_auto(const char *remote, const char *head_name,
+			struct strbuf *b_local_head) {
+	struct strbuf buf_prefix = STRBUF_INIT;
+	const char *prev_head = NULL;
+
+	strbuf_addf(&buf_prefix, "refs/remotes/%s/", remote);
+	skip_prefix(b_local_head->buf, buf_prefix.buf, &prev_head);
+
+	if (prev_head && !strcmp(prev_head, head_name))
+		printf(_("'%s/HEAD' is unchanged and points to '%s'\n"),
+			remote, head_name);
+	else if (prev_head)
+		printf(_("'%s/HEAD' has changed from '%s' and now points to '%s'\n"),
+			remote, prev_head, head_name);
+	else if (!b_local_head->len)
+		printf(_("'%s/HEAD' is now created and points to '%s'\n"),
+			remote, head_name);
+	else
+		printf(_("'%s/HEAD' used to point to '%s' "
+			"(which is not a remote branch), but now points to '%s'\n"),
+			remote, b_local_head->buf, head_name);
+	strbuf_release(&buf_prefix);
+}
+
 static int set_head(int argc, const char **argv, const char *prefix)
 {
 	int i, opt_a = 0, opt_d = 0, result = 0;
-	struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT;
+	struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT,
+		b_local_head = STRBUF_INIT;
 	char *head_name = NULL;
 	struct ref_store *refs = get_main_ref_store(the_repository);
 
@@ -1445,15 +1470,17 @@  static int set_head(int argc, const char **argv, const char *prefix)
 		/* make sure it's valid */
 		if (!refs_ref_exists(refs, b_remote_head.buf))
 			result |= error(_("Not a valid ref: %s"), b_remote_head.buf);
-		else if (refs_update_symref(refs, b_head.buf, b_remote_head.buf, "remote set-head"))
+		else if (refs_update_symref_extended(refs, b_head.buf, b_remote_head.buf,
+					"remote set-head", &b_local_head))
 			result |= error(_("Could not setup %s"), b_head.buf);
 		else if (opt_a)
-			printf("%s/HEAD set to %s\n", argv[0], head_name);
+			report_set_head_auto(argv[0], head_name, &b_local_head);
 		free(head_name);
 	}
 
 	strbuf_release(&b_head);
 	strbuf_release(&b_remote_head);
+	strbuf_release(&b_local_head);
 	return result;
 }
 
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 9b50276646..0ea86d51a4 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -432,12 +432,51 @@  test_expect_success 'set-head --auto' '
 	)
 '
 
+test_expect_success 'set-head --auto detects creation' '
+	(
+		cd test &&
+		git symbolic-ref -d refs/remotes/origin/HEAD &&
+		git remote set-head --auto origin >output &&
+		echo "${SQ}origin/HEAD${SQ} is now created and points to ${SQ}main${SQ}" >expect &&
+		test_cmp expect output
+	)
+'
+
+test_expect_success 'set-head --auto detects no change' '
+	(
+		cd test &&
+		git remote set-head --auto origin >output &&
+		echo "${SQ}origin/HEAD${SQ} is unchanged and points to ${SQ}main${SQ}" >expect &&
+		test_cmp expect output
+	)
+'
+
+test_expect_success 'set-head --auto detects change' '
+	(
+		cd test &&
+		git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/ahead &&
+		git remote set-head --auto origin >output &&
+		echo "${SQ}origin/HEAD${SQ} has changed from ${SQ}ahead${SQ} and now points to ${SQ}main${SQ}" >expect &&
+		test_cmp expect output
+	)
+'
+
+test_expect_success 'set-head --auto detects strange ref' '
+	(
+		cd test &&
+		git symbolic-ref refs/remotes/origin/HEAD refs/heads/main &&
+		git remote set-head --auto origin >output &&
+		echo "${SQ}origin/HEAD${SQ} used to point to ${SQ}refs/heads/main${SQ} (which is not a remote branch), but now points to ${SQ}main${SQ}" >expect &&
+		test_cmp expect output
+	)
+'
+
 test_expect_success 'set-head --auto has no problem w/multiple HEADs' '
 	(
 		cd test &&
 		git fetch two "refs/heads/*:refs/remotes/two/*" &&
 		git remote set-head --auto two >output 2>&1 &&
-		echo "two/HEAD set to main" >expect &&
+		echo "${SQ}two/HEAD${SQ} is now created and points to ${SQ}main${SQ}" >expect &&
 		test_cmp expect output
 	)
 '
@@ -456,6 +495,16 @@  test_expect_success 'set-head explicit' '
 	)
 '
 
+test_expect_success 'set-head --auto reports change' '
+	(
+		cd test &&
+		git remote set-head origin side2 &&
+		git remote set-head --auto origin >output 2>&1 &&
+		echo "${SQ}origin/HEAD${SQ} has changed from ${SQ}side2${SQ} and now points to ${SQ}main${SQ}" >expect &&
+		test_cmp expect output
+	)
+'
+
 cat >test/expect <<EOF
 Pruning origin
 URL: $(pwd)/one