cgit: Fix guessing default branchch/for-jason

Even when HEAD is set to "main" in a repository, cgit still uses the
"master" branch to detect the age of the last commit.

Example:

    $ cat repositories/openwrt/openwrt.git/HEAD
    ref: refs/heads/main

    $ stat repositories/openwrt/openwrt.git/refs/heads/master
    Modify: 2024-02-22 23:00:01.285731731 +0000

    $ stat repositories/openwrt/openwrt.git/refs/heads/main
    Modify: 2026-02-27 15:33:49.506017172 +0000

In this situation, cgit displays "25 months" for this repository on the index page.

I guess the internal format for HEAD has changed at some point, so it
needs to be taken into account when parsing it in cgit.

Signed-off-by: Baptiste Jonglez <git@bitsofnetworks.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/cgit.c b/cgit.c
index 3dc55c3..2efbb2c 100644
--- a/cgit.c
+++ b/cgit.c
@@ -496,7 +496,7 @@ static char *guess_defbranch(void)
 
 	ref = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
 				     "HEAD", 0, &oid, NULL);
-	if (!ref || !skip_prefix(ref, "refs/heads/", &refname))
+	if (!ref || !skip_prefix(ref, "ref: refs/heads/", &refname))
 		return "master";
 	return xstrdup(refname);
 }