Fix T40307: Crash with freestyle and particle hair.

The scene file provided by the problem report has many degenerate faces coming from
a particle system.  These zero-area faces were not expected in the ray-casting line visibility
algorithms of Freestyle.  Now degenerate faces are properly excluded from the imported
mesh data and not fed to the line visibility algorithms.

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/freestyle/intern/application/Controller.cpp b/source/blender/freestyle/intern/application/Controller.cpp
index 2bd31ea03a1..176199600ac 100644
--- a/source/blender/freestyle/intern/application/Controller.cpp
+++ b/source/blender/freestyle/intern/application/Controller.cpp
@@ -298,12 +298,19 @@ int Controller::LoadMesh(Render *re, SceneRenderLayer *srl)
 
 	_bboxDiag = (_RootNode->bbox().getMax() - _RootNode->bbox().getMin()).norm();
 	if (G.debug & G_DEBUG_FREESTYLE) {
-		cout << "Triangles nb     : " << _SceneNumFaces << endl;
+		cout << "Triangles nb     : " << _SceneNumFaces << " imported, " <<
+		        _winged_edge->getNumFaces() << " retained" << endl;
 		cout << "Bounding Box     : " << _bboxDiag << endl;
 	}
 
 	ClearRootNode();
 
+	_SceneNumFaces = _winged_edge->getNumFaces();
+	if (_SceneNumFaces == 0) {
+		DeleteWingedEdge();
+		return 1;
+	}
+
 	return 0;
 }