From 6ec7c05b9b753df2058dda52b10b6943a5626036 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 23 Nov 2012 16:56:17 +0100 Subject: [PATCH] qom: dynamic_cast of NULL is always NULL Trying to cast a NULL value will cause a crash. Returning NULL is also sensible, and it is also what the type-unsafe DO_UPCAST macro does. Reported-by: Markus Armbruster Signed-off-by: Paolo Bonzini Signed-off-by: Anthony Liguori (cherry picked from commit b7f43fe46029d8fd0594cd599fa2599dcce0f553) Signed-off-by: Michael Roth --- qom/object.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/qom/object.c b/qom/object.c index e3e9242..f33e84d 100644 --- a/qom/object.c +++ b/qom/object.c @@ -417,7 +417,7 @@ void object_delete(Object *obj) Object *object_dynamic_cast(Object *obj, const char *typename) { - if (object_class_dynamic_cast(object_get_class(obj), typename)) { + if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) { return obj; } @@ -430,7 +430,7 @@ Object *object_dynamic_cast_assert(Object *obj, const char *typename) inst = object_dynamic_cast(obj, typename); - if (!inst) { + if (!inst && obj) { fprintf(stderr, "Object %p is not an instance of type %s\n", obj, typename); abort();