[Bf-blender-cvs] [b6481cbbe56] blender-v2.79a-release: Fix T53823: Particle weight brush crash

[Campbell Barton]

Commit: b6481cbbe56a7d03791c73a5d07d29f1a3401d81
Author: Campbell Barton
Date:   Fri Jan 19 12:25:09 2018 +1100
Branches: blender-v2.79a-release
https://developer.blender.org/rBb6481cbbe56a7d03791c73a5d07d29f1a3401d81

Fix T53823: Particle weight brush crash

Entering particle edit mode w/ the weight brush enabled crashed
on non-hair particle systems.

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

M	source/blender/blenkernel/intern/particle.c

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

diff --git a/source/blender/blenkernel/intern/particle.c b/source/blender/blenkernel/intern/particle.c
index 455ca3ebbb6..6b5d687196e 100644
--- a/source/blender/blenkernel/intern/particle.c
+++ b/source/blender/blenkernel/intern/particle.c
@@ -2794,7 +2794,9 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 
 	/* frs_sec = (psys || edit->pid.flag & PTCACHE_VEL_PER_SEC) ? 25.0f : 1.0f; */ /* UNUSED */
 
-	if (pset->brushtype == PE_BRUSH_WEIGHT) {
+	const bool use_weight = (pset->brushtype == PE_BRUSH_WEIGHT) && (psys != NULL) && (psys->particles != NULL);
+
+	if (use_weight) {
 		; /* use weight painting colors now... */
 	}
 	else {
@@ -2824,7 +2826,7 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 
 
 		/* should init_particle_interpolation set this ? */
-		if (pset->brushtype == PE_BRUSH_WEIGHT) {
+		if (use_weight) {
 			pind.hkey[0] = NULL;
 			/* pa != NULL since the weight brush is only available for hair */
 			pind.hkey[0] = pa->hair;
@@ -2885,7 +2887,7 @@ void psys_cache_edit_paths(Scene *scene, Object *ob, PTCacheEdit *edit, float cf
 			}
 
 			/* selection coloring in edit mode */
-			if (pset->brushtype == PE_BRUSH_WEIGHT) {
+			if (use_weight) {
 				if (k == 0) {
 					weight_to_rgb(ca->col, pind.hkey[1]->weight);
 				}