Merge branch 'blender-v2.93-release'

source/blender/blenkernel/BKE_lib_id.h

@@ -104,6 +104,10 @@ enum {
    * specific code in some copy cases (mostly for node trees). */
   LIB_ID_CREATE_LOCAL = 1 << 9,
 
+  /** Create for the depsgraph, when set #LIB_TAG_COPIED_ON_WRITE must be set.
+   * Internally this is used to share some pointers instead of duplicating them. */
+  LIB_ID_COPY_SET_COPIED_ON_WRITE = 1 << 10,
+
   /* *** Specific options to some ID types or usages. *** */
   /* *** May be ignored by unrelated ID copying functions. *** */
   /** Object only, needed by make_local code. */

source/blender/blenkernel/intern/lib_id.c

@@ -1245,6 +1245,13 @@ void BKE_libblock_copy_ex(Main *bmain, const ID *id, ID **r_newid, const int ori
   }
   BLI_assert(new_id != NULL);
 
+  if ((flag & LIB_ID_COPY_SET_COPIED_ON_WRITE) != 0) {
+    new_id->tag |= LIB_TAG_COPIED_ON_WRITE;
+  }
+  else {
+    new_id->tag &= ~LIB_TAG_COPIED_ON_WRITE;
+  }
+
   const size_t id_len = BKE_libblock_get_alloc_info(GS(new_id->name), NULL);
   const size_t id_offset = sizeof(ID);
   if ((int)id_len - (int)id_offset > 0) { /* signed to allow neg result */ /* XXX ????? */

source/blender/blenkernel/intern/object.c

@@ -2289,7 +2289,7 @@ Object *BKE_object_add_for_data(
 void BKE_object_copy_softbody(Object *ob_dst, const Object *ob_src, const int flag)
 {
   SoftBody *sb = ob_src->soft;
-  bool tagged_no_main = ob_dst->id.tag & LIB_TAG_NO_MAIN;
+  const bool is_orig = (flag & LIB_ID_COPY_SET_COPIED_ON_WRITE) == 0;
 
   ob_dst->softflag = ob_src->softflag;
   if (sb == NULL) {
@@ -2330,7 +2330,7 @@ void BKE_object_copy_softbody(Object *ob_dst, const Object *ob_src, const int fl
 
   sbn->scratch = NULL;
 
-  if (!tagged_no_main) {
+  if (is_orig) {
     sbn->shared = MEM_dupallocN(sb->shared);
     sbn->shared->pointcache = BKE_ptcache_copy_list(
         &sbn->shared->ptcaches, &sb->shared->ptcaches, flag);

source/blender/blenkernel/intern/rigidbody.c

@@ -260,10 +260,12 @@ static RigidBodyOb *rigidbody_copy_object(const Object *ob, const int flag)
   RigidBodyOb *rboN = NULL;
 
   if (ob->rigidbody_object) {
+    const bool is_orig = (flag & LIB_ID_COPY_SET_COPIED_ON_WRITE) == 0;
+
     /* just duplicate the whole struct first (to catch all the settings) */
     rboN = MEM_dupallocN(ob->rigidbody_object);
 
-    if ((flag & LIB_ID_CREATE_NO_MAIN) == 0) {
+    if (is_orig) {
       /* This is a regular copy, and not a CoW copy for depsgraph evaluation */
       rboN->shared = MEM_callocN(sizeof(*rboN->shared), "RigidBodyOb_Shared");
     }

source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc

@@ -304,7 +304,8 @@ bool id_copy_inplace_no_main(const ID *id, ID *newid)
   bool result = (BKE_id_copy_ex(nullptr,
                                 (ID *)id_for_copy,
                                 &newid,
-                                LIB_ID_COPY_LOCALIZE | LIB_ID_CREATE_NO_ALLOCATE) != nullptr);
+                                (LIB_ID_COPY_LOCALIZE | LIB_ID_CREATE_NO_ALLOCATE |
+                                 LIB_ID_COPY_SET_COPIED_ON_WRITE)) != nullptr);
 
 #ifdef NESTED_ID_NASTY_WORKAROUND
   if (result) {
@@ -333,7 +334,8 @@ bool scene_copy_inplace_no_main(const Scene *scene, Scene *new_scene)
   bool result = (BKE_id_copy_ex(nullptr,
                                 id_for_copy,
                                 (ID **)&new_scene,
-                                LIB_ID_COPY_LOCALIZE | LIB_ID_CREATE_NO_ALLOCATE) != nullptr);
+                                (LIB_ID_COPY_LOCALIZE | LIB_ID_CREATE_NO_ALLOCATE |
+                                 LIB_ID_COPY_SET_COPIED_ON_WRITE)) != nullptr);
 
 #ifdef NESTED_ID_NASTY_WORKAROUND
   if (result) {

source/blender/makesdna/DNA_ID.h

@@ -555,8 +555,15 @@ enum {
   /* RESET_AFTER_USE tag existing data before linking so we know what is new. */
   LIB_TAG_PRE_EXISTING = 1 << 11,
 
-  /* The data-block is a copy-on-write/localized version. */
+  /**
+   * The data-block is a copy-on-write/localized version.
+   *
+   * \warning This should not be cleared on existing data.
+   * If support for this is needed, see T88026 as this flag controls memory ownership
+   * of physics *shared* pointers.
+   */
   LIB_TAG_COPIED_ON_WRITE = 1 << 12,
+
   LIB_TAG_COPIED_ON_WRITE_EVAL_RESULT = 1 << 13,
   LIB_TAG_LOCALIZED = 1 << 14,