Skip a ref whose object cannot be parsed

A dangling or unreadable ref was described through a null object.

1 file changed, 7 insertions, 1 deletion

diff --git a/source/shared.c b/source/shared.c
index 5cd26a9..24f9c3c 100644
--- a/source/shared.c
+++ b/source/shared.c
@@ -165,9 +165,15 @@ static struct refinfo *cgit_mk_refinfo(const char *refname, const struct object_
 {
 	struct refinfo *ref;
 
-	ref = xmalloc(sizeof (struct refinfo));
+	ref = xcalloc(1, sizeof (struct refinfo));
 	ref->refname = xstrdup(refname);
 	ref->object = parse_object(the_repository, oid);
+	if (!ref->object) {
+		// A dangling or unreadable ref has no object to describe.
+		free((char *)ref->refname);
+		free(ref);
+		return NULL;
+	}
 	switch (ref->object->type) {
 	case OBJ_TAG:
 		ref->tag = cgit_parse_tag((struct tag *)ref->object);