[Bf-blender-cvs] [2ccc52a7f18] blender-v2.81-release: Fix T71741: Crash showing the object relations menu

[Campbell Barton]

Commit: 2ccc52a7f18ae2cf242dbf178d5c59b304990c29
Author: Campbell Barton
Date:   Sat Nov 23 02:55:07 2019 +1100
Branches: blender-v2.81-release
https://developer.blender.org/rB2ccc52a7f18ae2cf242dbf178d5c59b304990c29

Fix T71741: Crash showing the object relations menu

===================================================================

M	source/blender/editors/object/object_modifier.c

===================================================================

diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index abcb4afa37d..303e53fa5ee 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -923,6 +923,7 @@ bool edit_modifier_poll_generic(bContext *C,
 {
   PointerRNA ptr = CTX_data_pointer_get_type(C, "modifier", rna_type);
   Object *ob = (ptr.owner_id) ? (Object *)ptr.owner_id : ED_object_active_context(C);
+  ModifierData *mod = ptr.data; /* May be NULL. */
 
   if (!ob || ID_IS_LINKED(ob)) {
     return 0;
@@ -935,8 +936,10 @@ bool edit_modifier_poll_generic(bContext *C,
   }
 
   if (ID_IS_OVERRIDE_LIBRARY(ob)) {
-    CTX_wm_operator_poll_msg_set(C, "Cannot edit modifiers coming from library override");
-    return (((ModifierData *)ptr.data)->flag & eModifierFlag_OverrideLibrary_Local) != 0;
+    if ((mod != NULL) && (mod->flag & eModifierFlag_OverrideLibrary_Local) == 0) {
+      CTX_wm_operator_poll_msg_set(C, "Cannot edit modifiers coming from library override");
+      return 0;
+    }
   }
 
   if (!is_editmode_allowed && CTX_data_edit_object(C) != NULL) {