cgit: override die routine globallyHEADmaster

We don't get any return value from compile_grep_patterns calling
compile_regexp_failed, causing the default die routine to print to
stderr and then for cgit to exit ungracefully.

Instead override the default die routine to show a normal error page.

Perhaps compile_grep_patterns ought to change upstream to return an
error. But this commit here will handle future issues as well, so
perhaps not a bad idea to do anyway.

Link: https://lists.zx2c4.com/pipermail/cgit/2026-March/004982.html
Link: https://lists.zx2c4.com/pipermail/cgit/2026-March/004983.html
Reported-by: Adrian C. <anrxc@sysphere.org>
Reported-by: Aiden Woodruff <aiden@aidenw.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/cgit.c b/cgit.c
index c91897a..c4dc94c 100644
--- a/cgit.c
+++ b/cgit.c
@@ -1058,6 +1058,12 @@ static int calc_ttl(void)
 	return ctx.cfg.cache_repo_ttl;
 }
 
+static NORETURN void cgit_die_routine(const char *msg, va_list params)
+{
+	cgit_vprint_error_page(400, "Bad request", msg, params);
+	exit(0);
+}
+
 int cmd_main(int argc, const char **argv)
 {
 	const char *path;
@@ -1065,6 +1071,7 @@ int cmd_main(int argc, const char **argv)
 
 	cgit_init_filters();
 	atexit(cgit_cleanup_filters);
+	set_die_routine(cgit_die_routine);
 
 	prepare_context();
 	cgit_repolist.length = 0;