Fix (unreported) design flow in how workspace's relation data are read from .blend file.

Relying on pointer addresses across different data-blocks is extremely
not recommended (and should be strictly forbidden ideally), in
particular in direct_link step of blend file reading.
- It assumes a specific order in reading of data, which is not ensured
  in future, and is in any case a very bad, non explicit, hidden
  dependency on behaviors of other parts of the codebase.
- It is intrinsically unsafe (as in, it makes writing bad code and making
  mistakes easy, see e.g. fix in rB84b3f6e049b35f9).
- It makes advanced handling of data-blocks harder (thinking about
  partial undo code e.g., even though in this specific case it was not
  an issue as we do not re-read neither windowmanagers nor worspaces
  during undo).

New code uses windows' `winid` instead as 'anchor' to find again proper
workspace hook in windows at read time.

As a bonus, it will also cleanup the list of relations from any invalid
ones (afaict it was never done previously).

Differential Revision: https://developer.blender.org/D9073

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 14a4643f760..b7c48234590 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -241,7 +241,7 @@ static void do_version_workspaces_after_lib_link(Main *bmain)
       if (screen->temp) {
         /* We do not generate a new workspace for those screens...
          * still need to set some data in win. */
-        win->workspace_hook = BKE_workspace_instance_hook_create(bmain);
+        win->workspace_hook = BKE_workspace_instance_hook_create(bmain, win->winid);
         win->scene = screen->scene;
         /* Deprecated from now on! */
         win->screen = NULL;
@@ -254,10 +254,10 @@ static void do_version_workspaces_after_lib_link(Main *bmain)
       WorkSpaceLayout *layout = BKE_workspace_layout_find(workspace, win->screen);
       BLI_assert(layout != NULL);
 
-      win->workspace_hook = BKE_workspace_instance_hook_create(bmain);
+      win->workspace_hook = BKE_workspace_instance_hook_create(bmain, win->winid);
 
       BKE_workspace_active_set(win->workspace_hook, workspace);
-      BKE_workspace_active_layout_set(win->workspace_hook, workspace, layout);
+      BKE_workspace_active_layout_set(win->workspace_hook, win->winid, workspace, layout);
 
       /* Move scene and view layer to window. */
       Scene *scene = screen->scene;