Fix for a crash caused by ReplaceMesh changing an objects physics shape. CcdShapeConstructionInfo::UpdateMesh() would change the CcdShapeConstructionInfo's m_meshObject, but didn't change m_meshShapeMap, which means the CcdShapeConstructionInfo object's destructor would not find it's m_meshObject in the m_meshShapeMap. This leaves some nasty dangling pointers laying around which caused issues if the scene was re-run, or the scene was changed to one that also had the mesh.

Note: This fix could cause other issues with shared physics meshes. In general, we may want to re-evaluate how we handle updating potentially shared physics meshes.

1 files changed, 9 insertions, 0 deletions

diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
index e63724fffc6..0a105ee1c1a 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
@@ -2048,6 +2048,15 @@ bool CcdShapeConstructionInfo::UpdateMesh(class KX_GameObject* gameobj, class RA
 		m_forceReInstance= true;
 	}
 
+	// Make sure to also replace the mesh in the shape map! Otherwise we leave dangling references when we free.
+	// Note, this whole business could cause issues with shared meshes. If we update one mesh, do we replace
+	// them all?
+	std::map<RAS_MeshObject*,CcdShapeConstructionInfo*>::iterator mit = m_meshShapeMap.find(m_meshObject);
+	if (mit != m_meshShapeMap.end()) {
+		m_meshShapeMap.erase(mit);
+		m_meshShapeMap[meshobj] = this;
+	}
+
 	m_meshObject= meshobj;
 	
 	if (dm) {