[Bf-blender-cvs] [b1fa2a8fbbd] master: Fix T59826: grease pencil crash with empty material slot.

[Brecht Van Lommel]

Commit: b1fa2a8fbbd9d17da7e1fea8afd29055f47113c8
Author: Brecht Van Lommel
Date:   Tue Jan 15 18:17:53 2019 +0100
Branches: master
https://developer.blender.org/rBb1fa2a8fbbd9d17da7e1fea8afd29055f47113c8

Fix T59826: grease pencil crash with empty material slot.

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

M	release/scripts/startup/bl_ui/space_view3d.py
M	source/blender/editors/gpencil/drawgpencil.c

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

diff --git a/release/scripts/startup/bl_ui/space_view3d.py b/release/scripts/startup/bl_ui/space_view3d.py
index 5c2cf8d529f..a6002dfaad4 100644
--- a/release/scripts/startup/bl_ui/space_view3d.py
+++ b/release/scripts/startup/bl_ui/space_view3d.py
@@ -3892,7 +3892,8 @@ class VIEW3D_MT_assign_material(Menu):
 
         for slot in ob.material_slots:
             mat = slot.material
-            layout.operator("gpencil.stroke_change_color", text=mat.name).material = mat.name
+            if mat:
+                layout.operator("gpencil.stroke_change_color", text=mat.name).material = mat.name
 
 
 class VIEW3D_MT_gpencil_copy_layer(Menu):
diff --git a/source/blender/editors/gpencil/drawgpencil.c b/source/blender/editors/gpencil/drawgpencil.c
index 72660c90837..548ccac7de3 100644
--- a/source/blender/editors/gpencil/drawgpencil.c
+++ b/source/blender/editors/gpencil/drawgpencil.c
@@ -602,7 +602,7 @@ static void gp_draw_stroke_fill(
 {
 	BLI_assert(gps->totpoints >= 3);
 	Material *ma = gpd->mat[gps->mat_nr];
-	MaterialGPencilStyle *gp_style = ma->gp_style;
+	MaterialGPencilStyle *gp_style = (ma) ? ma->gp_style : NULL;
 
 	/* Calculate triangles cache for filling area (must be done only after changes) */
 	if ((gps->flag & GP_STROKE_RECALC_GEOMETRY) || (gps->tot_triangles == 0) || (gps->triangles == NULL)) {
@@ -1013,7 +1013,7 @@ static void gp_draw_strokes(tGPDdraw *tgpw)
 		}
 		/* check if the color is visible */
 		Material *ma = tgpw->gpd->mat[gps->mat_nr];
-		MaterialGPencilStyle *gp_style = ma->gp_style;
+		MaterialGPencilStyle *gp_style = (ma) ? ma->gp_style : NULL;
 
 		if ((gp_style == NULL) ||
 		    (gp_style->flag & GP_STYLE_COLOR_HIDE) ||
@@ -1233,7 +1233,7 @@ static void gp_draw_strokes_edit(
 		/* verify color lock */
 		{
 			Material *ma = gpd->mat[gps->mat_nr];
-			MaterialGPencilStyle *gp_style = ma->gp_style;
+			MaterialGPencilStyle *gp_style = (ma) ? ma->gp_style : NULL;
 
 			if (gp_style != NULL) {
 				if (gp_style->flag & GP_STYLE_COLOR_HIDE) {
@@ -1263,7 +1263,7 @@ static void gp_draw_strokes_edit(
 		/* for now, we assume that the base color of the points is not too close to the real color */
 		/* set color using material */
 		Material *ma = gpd->mat[gps->mat_nr];
-		MaterialGPencilStyle *gp_style = ma->gp_style;
+		MaterialGPencilStyle *gp_style = (ma) ? ma->gp_style : NULL;
 
 		float selectColor[4];
 		UI_GetThemeColor3fv(TH_GP_VERTEX_SELECT, selectColor);
@@ -1307,10 +1307,14 @@ static void gp_draw_strokes_edit(
 				immAttr3fv(color, selectColor);
 				immAttr1f(size, vsize);
 			}
-			else {
+			else if (gp_style) {
 				immAttr3fv(color, gp_style->stroke_rgba);
 				immAttr1f(size, bsize);
 			}
+			else {
+				immAttr3f(color, 0.0f, 0.0f, 0.0f);
+				immAttr1f(size, bsize);
+			}
 
 			/* then position */
 			if (gps->flag & GP_STROKE_3DSPACE) {