[Bf-blender-cvs] [e8e4a795122] master: Fix T86390 Exact Boolean crash.

[Howard Trickey]

Commit: e8e4a795122a10dfa0b10c8e91247a1ab3288319
Author: Howard Trickey
Date:   Sat Mar 13 19:23:14 2021 -0500
Branches: master
https://developer.blender.org/rBe8e4a795122a10dfa0b10c8e91247a1ab3288319

Fix T86390 Exact Boolean crash.

The code has to keep track of "zero volume" cells and I forgot
that there were cases where that needed be be invalidated.

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

M	source/blender/blenlib/intern/mesh_boolean.cc

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

diff --git a/source/blender/blenlib/intern/mesh_boolean.cc b/source/blender/blenlib/intern/mesh_boolean.cc
index cd7d0a812e4..bc12ff1a652 100644
--- a/source/blender/blenlib/intern/mesh_boolean.cc
+++ b/source/blender/blenlib/intern/mesh_boolean.cc
@@ -408,6 +408,7 @@ class Cell {
   void add_patch(int p)
   {
     patches_.add(p);
+    zero_volume_ = false; /* If it was true before, it no longer is. */
   }
 
   const Set<int> &patches() const