fix [#27627] Strange behavior with solid open gl lights

disable turning off all lights in the user preferences.

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index b67805c97b9..14af5ed7a3f 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -245,6 +245,13 @@ static void rna_UserDef_weight_color_update(Main *bmain, Scene *scene, PointerRN
 
 static void rna_UserDef_viewport_lights_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 {
+	/* if all lights are off gpu_draw resets them all, [#27627]
+	 * so disallow them all to be disabled */
+	if(U.light[0].flag==0 && U.light[1].flag==0 && U.light[2].flag==0) {
+		SolidLight *light= ptr->data;
+		light->flag |= 1;
+	}
+
 	WM_main_add_notifier(NC_SPACE|ND_SPACE_VIEW3D|NS_VIEW3D_GPU, NULL);
 	rna_userdef_update(bmain, scene, ptr);
 }