Implement T77959: Never duplicate linked data during deep-copy.

Note that this behavior is enforced on user level for now, but on code
side it is controlled with a flag, which should make it easy to refine
that behavior if needed.

Only exception is when we duplicate a linked ID directly (then we assume
user wants a local deep-copy of that linked data, and we always also
duplicate linked sub-data-blocks).

Note that this commit also slightly refactor the handling of actions of
animdata, by simplifying `BKE_animdata_copy_id_action()` and adding an
explicit new `BKE_animdata_duplicate_id_action()` to be used during ID
duplication (deep copy).

This also allows us to get rid of the special case for liboverrides.

1 files changed, 26 insertions, 28 deletions

diff --git a/source/blender/blenkernel/intern/lib_id.c b/source/blender/blenkernel/intern/lib_id.c
index 7c09ae51344..eb440de1a6f 100644
--- a/source/blender/blenkernel/intern/lib_id.c
+++ b/source/blender/blenkernel/intern/lib_id.c
@@ -611,41 +611,39 @@ bool BKE_id_copy(Main *bmain, const ID *id, ID **newid)
  * Invokes the appropriate copy method for the block and returns the result in
  * newid, unless test. Returns true if the block can be copied.
  */
-ID *BKE_id_copy_for_duplicate(Main *bmain,
-                              ID *id,
-                              const bool is_owner_id_liboverride,
-                              const eDupli_ID_Flags duplicate_flags)
+ID *BKE_id_copy_for_duplicate(Main *bmain, ID *id, const eDupli_ID_Flags duplicate_flags)
 {
   if (id == NULL) {
-    return NULL;
+    return id;
   }
   if (id->newid == NULL) {
-    if (!is_owner_id_liboverride || !ID_IS_LINKED(id)) {
-      ID *id_new;
-      BKE_id_copy(bmain, id, &id_new);
-      /* Copying add one user by default, need to get rid of that one. */
-      id_us_min(id_new);
-      ID_NEW_SET(id, id_new);
-
-      /* Shape keys are always copied with their owner ID, by default. */
-      ID *key_new = (ID *)BKE_key_from_id(id_new);
-      ID *key = (ID *)BKE_key_from_id(id);
-      if (key != NULL) {
-        ID_NEW_SET(key, key_new);
-      }
+    const bool do_linked_id = (duplicate_flags & USER_DUP_LINKED_ID) != 0;
+    if (!(do_linked_id || !ID_IS_LINKED(id))) {
+      return id;
+    }
 
-      /* Note: embedded data (root nodetrees and master collections) should never be referenced by
-       * anything else, so we do not need to set their newid pointer and flag. */
+    ID *id_new;
+    BKE_id_copy(bmain, id, &id_new);
+    /* Copying add one user by default, need to get rid of that one. */
+    id_us_min(id_new);
+    ID_NEW_SET(id, id_new);
 
-      if (duplicate_flags & USER_DUP_ACT) {
-        BKE_animdata_copy_id_action(bmain, id_new, true);
-        if (key_new != NULL) {
-          BKE_animdata_copy_id_action(bmain, key_new, true);
-        }
-        /* Note that actions of embedded data (root nodetrees and master collections) are handled
-         * by `BKE_animdata_copy_id_action` as well. */
-      }
+    /* Shape keys are always copied with their owner ID, by default. */
+    ID *key_new = (ID *)BKE_key_from_id(id_new);
+    ID *key = (ID *)BKE_key_from_id(id);
+    if (key != NULL) {
+      ID_NEW_SET(key, key_new);
+    }
+
+    /* Note: embedded data (root nodetrees and master collections) should never be referenced by
+     * anything else, so we do not need to set their newid pointer and flag. */
+
+    BKE_animdata_duplicate_id_action(bmain, id_new, duplicate_flags);
+    if (key_new != NULL) {
+      BKE_animdata_duplicate_id_action(bmain, id_new, duplicate_flags);
     }
+    /* Note that actions of embedded data (root nodetrees and master collections) are handled
+     * by `BKE_animdata_duplicate_id_action` as well. */
   }
   return id->newid;
 }