BlenLoad: Ensure linked IDs are properly sorted.

So far, linked IDs were not properly sorted at all, only the ones
explicitely linked from WM code would be, but any indirectly linked
data-blocks would end up in some random order in their lists.

While not ideal, this is not a huge issue in itself, but it had bad
side-effects, e.g. causing (recursive) resync of overrides to happen in
random order, leading to mismatches between name indices of newly-generated
override IDs and the one existings e.g.

And in general, it is much better to be consistent here.

Note that the file sub-version is bumped for this commit, since some
sorting (the directly linked IDs which we keep a reference to) should
never need to be re-done after relevant doversion process.

source/blender/blenkernel/BKE_blender_version.h

@@ -39,7 +39,7 @@ extern "C" {
 
 /* Blender file format version. */
 #define BLENDER_FILE_VERSION BLENDER_VERSION
-#define BLENDER_FILE_SUBVERSION 2
+#define BLENDER_FILE_SUBVERSION 3
 
 /* Minimum Blender version that supports reading file written with the current
  * version. Older Blender versions will test this and show a warning if the file

source/blender/blenloader/intern/readfile.c

@@ -4452,7 +4452,9 @@ static void expand_doit_library(void *fdhandle, Main *mainvar, void *old)
     if (id == NULL) {
       /* ID has not been read yet, add placeholder to the main of the
        * library it belongs to, so that it will be read later. */
-      read_libblock(fd, libmain, bhead, fd->id_tag_extra | LIB_TAG_INDIRECT, false, NULL);
+      read_libblock(fd, libmain, bhead, fd->id_tag_extra | LIB_TAG_INDIRECT, false, &id);
+      id_sort_by_name(which_libbase(libmain, GS(id->name)), id, id->prev);
+
       /* commented because this can print way too much */
       // if (G.debug & G_DEBUG) printf("expand_doit: other lib %s\n", lib->filepath);
 
@@ -4512,7 +4514,8 @@ static void expand_doit_library(void *fdhandle, Main *mainvar, void *old)
                     bhead,
                     fd->id_tag_extra | LIB_TAG_NEED_EXPAND | LIB_TAG_INDIRECT,
                     false,
-                    NULL);
+                    &id);
+      id_sort_by_name(which_libbase(mainvar, GS(id->name)), id, id->prev);
     }
     else {
       /* Convert any previously read weak link to regular link

source/blender/blenloader/intern/versioning_300.c

@@ -27,6 +27,7 @@
 
 #include "DNA_brush_types.h"
 #include "DNA_genfile.h"
+#include "DNA_listBase.h"
 #include "DNA_modifier_types.h"
 #include "DNA_text_types.h"
 
@@ -37,6 +38,43 @@
 #include "BLO_readfile.h"
 #include "readfile.h"
 
+static void sort_linked_ids(Main *bmain)
+{
+  ListBase *lb;
+  FOREACH_MAIN_LISTBASE_BEGIN (bmain, lb) {
+    ListBase temp_list;
+    BLI_listbase_clear(&temp_list);
+    LISTBASE_FOREACH_MUTABLE (ID *, id, lb) {
+      if (ID_IS_LINKED(id)) {
+        BLI_remlink(lb, id);
+        BLI_addtail(&temp_list, id);
+        id_sort_by_name(&temp_list, id, NULL);
+      }
+    }
+    BLI_movelisttolist(lb, &temp_list);
+  }
+  FOREACH_MAIN_LISTBASE_END;
+}
+
+static void assert_sorted_ids(Main *bmain)
+{
+#ifndef NDEBUG
+  ListBase *lb;
+  FOREACH_MAIN_LISTBASE_BEGIN (bmain, lb) {
+    ID *id_prev = NULL;
+    LISTBASE_FOREACH (ID *, id, lb) {
+      if (id_prev == NULL) {
+        continue;
+      }
+      BLI_assert(id_prev->lib != id->lib || BLI_strcasecmp(id_prev->name, id->name) < 0);
+    }
+  }
+  FOREACH_MAIN_LISTBASE_END;
+#else
+  UNUSED_VARS_NDEBUG(bmain);
+#endif
+}
+
 void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
 {
   if (MAIN_VERSION_ATLEAST(bmain, 300, 0) && !MAIN_VERSION_ATLEAST(bmain, 300, 1)) {
@@ -47,19 +85,8 @@ void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
       }
     }
   }
-  /**
-   * Versioning code until next subversion bump goes here.
-   *
-   * \note Be sure to check when bumping the version:
-   * - #blo_do_versions_300 in this file.
-   * - "versioning_userdef.c", #blo_do_versions_userdef
-   * - "versioning_userdef.c", #do_versions_theme
-   *
-   * \note Keep this message at the bottom of the function.
-   */
-  {
-    /* Keep this block, even when empty. */
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 300, 3)) {
     /* Use new texture socket in Attribute Sample Texture node. */
     LISTBASE_FOREACH (bNodeTree *, ntree, &bmain->nodetrees) {
       if (ntree->type != NTREE_GEOMETRY) {
@@ -83,6 +110,26 @@ void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
         node->id = NULL;
       }
     }
+
+    sort_linked_ids(bmain);
+    assert_sorted_ids(bmain);
+  }
+  if (MAIN_VERSION_ATLEAST(bmain, 300, 3)) {
+    assert_sorted_ids(bmain);
+  }
+
+  /**
+   * Versioning code until next subversion bump goes here.
+   *
+   * \note Be sure to check when bumping the version:
+   * - #blo_do_versions_300 in this file.
+   * - "versioning_userdef.c", #blo_do_versions_userdef
+   * - "versioning_userdef.c", #do_versions_theme
+   *
+   * \note Keep this message at the bottom of the function.
+   */
+  {
+    /* Keep this block, even when empty. */
   }
 }