fix annoying bug where image open from ID template didn't open in the existing images path.

source/blender/editors/interface/interface_templates.c

@@ -254,7 +254,7 @@ static void template_id_cb(bContext *C, void *arg_litem, void *arg_event)
 			break;
 		case UI_ID_OPEN:
 		case UI_ID_ADD_NEW:
-			/* these call uiIDContextPropertySet */
+			/* these call uiIDContextProperty */
 			break;
 		case UI_ID_DELETE:
 			memset(&idptr, 0, sizeof(idptr));

source/blender/editors/space_image/image_ops.c

@@ -901,6 +901,25 @@ static int image_open_invoke(bContext *C, wmOperator *op, wmEvent *UNUSED(event)
 			ima = tex->ima;
 	}
 
+	if (ima == NULL) {
+		PointerRNA ptr;
+		PropertyRNA *prop;
+
+		/* hook into UI */
+		uiIDContextProperty(C, &ptr, &prop);
+
+		if (prop) {
+			PointerRNA oldptr;
+
+			oldptr = RNA_property_pointer_get(&ptr, prop);
+			ima = (Image *)oldptr.id.data;
+			/* unlikely but better avoid strange crash */
+			if (ima && GS(ima->id.name) != ID_IM) {
+				ima = NULL;
+			}
+		}
+	}
+
 	if (ima)
 		path = ima->name;