From c632396733ab5b9e338cb532501cc84d19cc67c2 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Thu, 23 Apr 2020 11:28:32 +1000
Subject: [PATCH] Fix T75991: crash when rigidbody encounters unknown
 constraint type

This just adds a check to prevent the crash,
Versioning invalid types still needed.
---
 source/blender/blenkernel/intern/rigidbody.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/source/blender/blenkernel/intern/rigidbody.c b/source/blender/blenkernel/intern/rigidbody.c
index f08de835a9d..4d37c2ea931 100644
--- a/source/blender/blenkernel/intern/rigidbody.c
+++ b/source/blender/blenkernel/intern/rigidbody.c
@@ -1027,6 +1027,11 @@ static void rigidbody_validate_sim_constraint(RigidBodyWorld *rbw, Object *ob, b
       return;
     }
 
+    /* When 'rbc->type' is unknown. */
+    if (rbc->physics_constraint == NULL) {
+      return;
+    }
+
     RB_constraint_set_enabled(rbc->physics_constraint, rbc->flag & RBC_FLAG_ENABLED);
 
     if (rbc->flag & RBC_FLAG_USE_BREAKING) {