Junio C Hamano [off-list ref] writes:

Bence Ferdinandy [off-list ref] writes:

quoted

+static void report_auto(const char *remote, const char *head_name,
+			struct strbuf *buf_prev) {
+	struct strbuf buf_prefix = STRBUF_INIT;
+	const char *prev_head;

I think we need to initialize prev_head to NULL.

quoted

+	strbuf_addf(&buf_prefix, "refs/remotes/%s/", remote);
+	skip_prefix(buf_prev->buf, buf_prefix.buf, &prev_head);

If the symref was not pointing into the "refs/remotes/<remote>/"
hierarchy previously, skip_prefix() comes back without touching
prev_head (i.e. not starting with the prefix does not clear it).

The two uninitialized prev_head were also noticed by compilers in
multiple jobs at GitHub CI.

https://github.com/git/git/actions/runs/11265515664