Replace the glibc-only `memrchr` for portability

1 file changed, 12 insertions, 1 deletion

diff --git a/source/ui-shared.c b/source/ui-shared.c
index df52a9b..eb68ab7 100644
--- a/source/ui-shared.c
+++ b/source/ui-shared.c
@@ -1247,6 +1247,17 @@ void cgit_print_snapshot_links(const struct cgit_repo *repo, const char *ref,
 	strbuf_release(&filename);
 }
 
+/* Portable reverse memchr: memrchr is a glibc extension absent on
+ * macOS and the BSDs. */
+static const char *find_last_char(const char *start, const char *end, int c)
+{
+	while (end > start) {
+		if (*--end == c)
+			return end;
+	}
+	return NULL;
+}
+
 void cgit_set_title_from_path(const char *path)
 {
 	struct strbuf sb = STRBUF_INIT;
@@ -1255,7 +1266,7 @@ void cgit_set_title_from_path(const char *path)
 	if (!path)
 		return;
 
-	for (last_slash = path + strlen(path); (slash = memrchr(path, '/', last_slash - path)) != NULL; last_slash = slash) {
+	for (last_slash = path + strlen(path); (slash = find_last_char(path, last_slash, '/')) != NULL; last_slash = slash) {
 		strbuf_add(&sb, slash + 1, last_slash - slash - 1);
 		strbuf_addstr(&sb, " \xc2\xab ");
 	}