Replace of (id->lib != NULL) check by meaningful macro.

Idea is to replace hard-to-track (id->lib != NULL) 'is linked datablock' check everywhere in Blender
by a macro doing the same thing. This will allow to easily spot those checks in future, and more importantly,
to easily change it (see work done in asset-engine branch).

Note: did not touch to readfile.c, since there most of the time 'id->lib' check actually concerns the pointer,
and not a check whether ID is linked or not. Will have a closer look at it later.

Reviewers: campbellbarton, brecht, sergey

Differential Revision: https://developer.blender.org/D2082

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/editors/object/object_data_transfer.c b/source/blender/editors/object/object_data_transfer.c
index 47ee6752e51..acee69daab7 100644
--- a/source/blender/editors/object/object_data_transfer.c
+++ b/source/blender/editors/object/object_data_transfer.c
@@ -300,7 +300,7 @@ static void data_transfer_exec_preprocess_objects(
 		}
 
 		me = ob->data;
-		if (me->id.lib) {
+		if (ID_IS_LINKED_DATABLOCK(me)) {
 			/* Do not transfer to linked data, not supported. */
 			BKE_reportf(op->reports, RPT_WARNING, "Skipping object '%s', linked data '%s' cannot be modified",
 			            ob->id.name + 2, me->id.name + 2);
@@ -330,7 +330,7 @@ static bool data_transfer_exec_is_object_valid(
 		me->id.tag &= ~LIB_TAG_DOIT;
 		return true;
 	}
-	else if (me->id.lib == NULL) {
+	else if (!ID_IS_LINKED_DATABLOCK(me)) {
 		/* Do not transfer apply operation more than once. */
 		/* XXX This is not nice regarding vgroups, which are half-Object data... :/ */
 		BKE_reportf(op->reports, RPT_WARNING,
@@ -387,7 +387,7 @@ static int data_transfer_exec(bContext *C, wmOperator *op)
 		return OPERATOR_FINISHED;
 	}
 
-	if (reverse_transfer && ((ID *)(ob_src->data))->lib) {
+	if (reverse_transfer && ID_IS_LINKED_DATABLOCK(ob_src->data)) {
 		/* Do not transfer to linked data, not supported. */
 		return OPERATOR_CANCELLED;
 	}