[Bf-blender-cvs] [f694d379294] master: Fix T59792: Cycles crash rendering motion pass with motion blur enabled.

[Brecht Van Lommel]

Commit: f694d3792941ce24092865cffb038aa0e5cc08f2
Author: Brecht Van Lommel
Date:   Wed Jan 2 17:46:57 2019 +0100
Branches: master
https://developer.blender.org/rBf694d3792941ce24092865cffb038aa0e5cc08f2

Fix T59792: Cycles crash rendering motion pass with motion blur enabled.

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

M	intern/cycles/render/film.cpp

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

diff --git a/intern/cycles/render/film.cpp b/intern/cycles/render/film.cpp
index d0f15496e50..355294e23b5 100644
--- a/intern/cycles/render/film.cpp
+++ b/intern/cycles/render/film.cpp
@@ -328,8 +328,17 @@ void Film::device_update(Device *device, DeviceScene *dscene, Scene *scene)
 	for(size_t i = 0; i < passes.size(); i++) {
 		Pass& pass = passes[i];
 
-		if(pass.type == PASS_NONE)
+		if(pass.type == PASS_NONE) {
 			continue;
+		}
+
+		/* Can't do motion pass if no motion vectors are available. */
+		if (pass.type == PASS_MOTION || pass.type == PASS_MOTION_WEIGHT) {
+			if (scene->need_motion() != Scene::MOTION_PASS) {
+				kfilm->pass_stride += pass.components;
+				continue;
+			}
+		}
 
 		int pass_flag = (1 << (pass.type % 32));
 		if(pass.type <= PASS_CATEGORY_MAIN_END) {