[Bf-blender-cvs] [cfaf92c0790] blender2.8: GP: Fix T56802 - Add/Delete Vertex Group crashes

[Antonioya]

Commit: cfaf92c0790f04e526339a1049a321f927f10118
Author: Antonioya
Date:   Fri Sep 14 16:08:54 2018 +0200
Branches: blender2.8
https://developer.blender.org/rBcfaf92c0790f04e526339a1049a321f927f10118

GP: Fix T56802 - Add/Delete Vertex Group crashes

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

M	source/blender/blenkernel/intern/gpencil.c
M	source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c

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

diff --git a/source/blender/blenkernel/intern/gpencil.c b/source/blender/blenkernel/intern/gpencil.c
index 08c490252e5..bc9aa0a96d2 100644
--- a/source/blender/blenkernel/intern/gpencil.c
+++ b/source/blender/blenkernel/intern/gpencil.c
@@ -1221,11 +1221,13 @@ void BKE_gpencil_vgroup_remove(Object *ob, bDeformGroup *defgroup)
 		for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
 			for (bGPDframe *gpf = gpl->frames.first; gpf; gpf = gpf->next) {
 				for (bGPDstroke *gps = gpf->strokes.first; gps; gps = gps->next) {
-					for (int i = 0; i < gps->totpoints; i++) {
-						dvert = &gps->dvert[i];
-						MDeformWeight *dw = defvert_find_index(dvert, def_nr);
-						if (dw != NULL) {
-							defvert_remove_group(dvert, dw);
+					if (gps->dvert != NULL) {
+						for (int i = 0; i < gps->totpoints; i++) {
+							dvert = &gps->dvert[i];
+							MDeformWeight *dw = defvert_find_index(dvert, def_nr);
+							if (dw != NULL) {
+								defvert_remove_group(dvert, dw);
+							}
 						}
 					}
 				}
@@ -1235,6 +1237,7 @@ void BKE_gpencil_vgroup_remove(Object *ob, bDeformGroup *defgroup)
 
 	/* Remove the group */
 	BLI_freelinkN(&ob->defbase, defgroup);
+	DEG_id_tag_update(&gpd->id, OB_RECALC_OB | OB_RECALC_DATA);
 }
 
 
diff --git a/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c b/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
index 079f76aad28..00235d0bfcb 100644
--- a/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
+++ b/source/blender/draw/engines/gpencil/gpencil_draw_cache_impl.c
@@ -507,7 +507,7 @@ GPUBatch *DRW_gpencil_get_edit_geom(bGPDstroke *gps, float alpha, short dflag)
 	for (int i = 0; i < gps->totpoints; i++, pt++) {
 		/* weight paint */
 		if (is_weight_paint) {
-			float weight = gps->dvert ? defvert_find_weight(dvert, vgindex) : 0.0f;
+			float weight = (dvert && dvert->dw) ? defvert_find_weight(dvert, vgindex) : 0.0f;
 			float hue = 2.0f * (1.0f - weight) / 3.0f;
 			hsv_to_rgb(hue, 1.0f, 1.0f, &selectColor[0], &selectColor[1], &selectColor[2]);
 			selectColor[3] = 1.0f;
@@ -585,7 +585,7 @@ GPUBatch *DRW_gpencil_get_edlin_geom(bGPDstroke *gps, float alpha, short UNUSED(
 	for (int i = 0; i < gps->totpoints; i++, pt++) {
 		/* weight paint */
 		if (is_weight_paint) {
-			float weight = gps->dvert ? defvert_find_weight(dvert, vgindex) : 0.0f;
+			float weight = (dvert && dvert->dw) ? defvert_find_weight(dvert, vgindex) : 0.0f;
 			float hue = 2.0f * (1.0f - weight) / 3.0f;
 			hsv_to_rgb(hue, 1.0f, 1.0f, &selectColor[0], &selectColor[1], &selectColor[2]);
 			selectColor[3] = 1.0f;