M cgit.c → cgit.c

@@ -177,6 +177,9 @@ }
 
 static void querystring_cb(const char *name, const char *value)
 {
+	if (!value)
+		value = "";
+
 	if (!strcmp(name,"r")) {
 		ctx.qry.repo = xstrdup(value);
 		ctx.repo = cgit_get_repoinfo(value);

M ui-tag.c → ui-tag.c

@@ -37,7 +37,10 @@ struct object *obj;
 	struct tag *tag;
 	struct taginfo *info;
 
-	if (get_sha1(revname, sha1)) {
+	if (!revname)
+		revname = ctx.qry.head;
+
+	if (get_sha1(fmt("refs/tags/%s", revname), sha1)) {
 		cgit_print_error(fmt("Bad tag reference: %s", revname));
 		return;
 	}