On Thu, Jun 30 2022, Junio C Hamano wrote:

Ævar Arnfjörð Bjarmason  [off-list ref] writes:

quoted

In 1c41d2805e4 (unpack_trees_options: free messages when done,
2018-05-21) we started calling clear_unpack_trees_porcelain() on this
codepath, but missed this error path, let's also clear what we've
allocated in that case.

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---
 builtin/checkout.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 2eefda81d8c..3d6762106e8 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c

@@ -750,6 +750,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		refresh_cache(REFRESH_QUIET);
 
 		if (unmerged_cache()) {
+			clear_unpack_trees_porcelain(&topts);
 			error(_("you need to resolve your current index first"));
 			return 1;
 		}

Does refresh_cache(REFRESH_QUIET) depend on the porcelain error
messages already set?  If not another way to fix it may be to delay
the call to setup_unpack_trees_porcelain() until it becomes needed.

But the patch as posted is certainly an improvement.

Yes, that would work too, I can do it that way if you'd like.

I was trying to keep these fixes as narrow as possible, and resist any
temptations to re-arrange code so as to avoid allocations, which we can
often do, but then instead of a 1-line diff it's 10, 50, 100... :)

In this case it'll be somewhere around 10, and just a code-move, so
maybe that's fine...