Fix crash running constraint, modifier, fx from missing NULL check

None of these generic poll functions had NULL pointer checks,
since all operators that use these functions expect a valid constraint,
modifier .. etc. Add the NULL check to the poll function.

Ref D11126

Reviewed By: mont29, Severin

1 files changed, 5 insertions, 0 deletions

diff --git a/source/blender/editors/object/object_constraint.c b/source/blender/editors/object/object_constraint.c
index 244124a6e0a..8ed1b862521 100644
--- a/source/blender/editors/object/object_constraint.c
+++ b/source/blender/editors/object/object_constraint.c
@@ -706,6 +706,11 @@ static bool edit_constraint_poll_generic(bContext *C,
     return false;
   }
 
+  if (!con) {
+    CTX_wm_operator_poll_msg_set(C, "Context missing active constraint");
+    return false;
+  }
+
   if (!is_liboverride_allowed && BKE_constraint_is_nonlocal_in_liboverride(ob, con)) {
     CTX_wm_operator_poll_msg_set(
         C, "Cannot edit constraints coming from linked data in a library override");