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, 1 insertions, 1 deletions

diff --git a/source/blender/editors/object/object_constraint.c b/source/blender/editors/object/object_constraint.c
index d7b7fd7040e..db8a4c1960f 100644
--- a/source/blender/editors/object/object_constraint.c
+++ b/source/blender/editors/object/object_constraint.c
@@ -584,7 +584,7 @@ static int edit_constraint_poll_generic(bContext *C, StructRNA *rna_type)
 		return 0;
 	}
 
-	if (ob->id.lib || (ptr.id.data && ((ID *)ptr.id.data)->lib)) {
+	if (ID_IS_LINKED_DATABLOCK(ob) || (ptr.id.data && ID_IS_LINKED_DATABLOCK(ptr.id.data))) {
 		CTX_wm_operator_poll_msg_set(C, "Cannot edit library data");
 		return 0;
 	}