Fix [#33962] Grease Pencil crashing blender

Own fault from grease pencil to curve enhacement. Fixed the bug itself, and made poll of convert operator more strict (no only active when there is something to convert, i.e. at least one stroke!).

1 files changed, 15 insertions, 4 deletions

diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index e4e640eeefc..671adfb8d1e 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -1387,12 +1387,15 @@ static void gp_layer_to_curve(bContext *C, ReportList *reports, bGPdata *gpd, bG
 static int gp_convert_check_has_valid_timing(bContext *C, bGPDlayer *gpl, wmOperator *op)
 {
 	Scene *scene = CTX_data_scene(C);
-	bGPDframe *gpf = gpencil_layer_getframe(gpl, CFRA, 0);
-	bGPDstroke *gps = gpf->strokes.first;
+	bGPDframe *gpf = NULL;
+	bGPDstroke *gps = NULL;
 	bGPDspoint *pt;
 	double base_time, cur_time, prev_time = -1.0;
 	int i, valid = TRUE;
 	
+	if (!gpl || !(gpf = gpencil_layer_getframe(gpl, CFRA, 0)) || !(gps = gpf->strokes.first))
+		return FALSE;
+	
 	do {
 		base_time = cur_time = gps->inittime;
 		if (cur_time <= prev_time) {
@@ -1438,11 +1441,19 @@ static void gp_convert_set_end_frame(struct Main *UNUSED(main), struct Scene *UN
 static int gp_convert_poll(bContext *C)
 {
 	bGPdata *gpd = gpencil_data_get_active(C);
+	bGPDlayer *gpl = NULL;
+	bGPDframe *gpf = NULL;
 	ScrArea *sa = CTX_wm_area(C);
 	Scene *scene = CTX_data_scene(C);
 
-	/* only if there's valid data, and the current view is 3D View */
-	return ((sa && sa->spacetype == SPACE_VIEW3D) && gpencil_layer_getactive(gpd) && (scene->obedit == NULL));
+	/* only if the current view is 3D View, if there's valid data (i.e. at least one stroke!),
+	 * and if we are not in edit mode!
+	 */
+	return ((sa && sa->spacetype == SPACE_VIEW3D) &&
+	        (gpl = gpencil_layer_getactive(gpd)) &&
+	        (gpf = gpencil_layer_getframe(gpl, CFRA, 0)) &&
+	        (gpf->strokes.first) &&
+	        (scene->obedit == NULL));
 }
 
 static int gp_convert_layer_exec(bContext *C, wmOperator *op)