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, 4 insertions, 4 deletions

diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index 610a06690cc..e8575374022 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -297,7 +297,7 @@ wmWindow *wm_window_new(const Main *bmain, wmWindowManager *wm, wmWindow *parent
   /* Dialogs may have a child window as parent. Otherwise, a child must not be a parent too. */
   win->parent = (!dialog && parent && parent->parent) ? parent->parent : parent;
   win->stereo3d_format = MEM_callocN(sizeof(Stereo3dFormat), "Stereo 3D Format (window)");
-  win->workspace_hook = BKE_workspace_instance_hook_create(bmain);
+  win->workspace_hook = BKE_workspace_instance_hook_create(bmain, win->winid);
 
   return win;
 }
@@ -327,7 +327,7 @@ wmWindow *wm_window_copy(Main *bmain,
   layout_new = duplicate_layout ?
                    ED_workspace_layout_duplicate(bmain, workspace, layout_old, win_dst) :
                    layout_old;
-  BKE_workspace_active_layout_set(win_dst->workspace_hook, workspace, layout_new);
+  BKE_workspace_active_layout_set(win_dst->workspace_hook, win_dst->winid, workspace, layout_new);
 
   *win_dst->stereo3d_format = *win_src->stereo3d_format;
 
@@ -2420,7 +2420,7 @@ WorkSpaceLayout *WM_window_get_active_layout(const wmWindow *win)
 }
 void WM_window_set_active_layout(wmWindow *win, WorkSpace *workspace, WorkSpaceLayout *layout)
 {
-  BKE_workspace_active_layout_set(win->workspace_hook, workspace, layout);
+  BKE_workspace_active_layout_set(win->workspace_hook, win->winid, workspace, layout);
 }
 
 /**
@@ -2434,7 +2434,7 @@ bScreen *WM_window_get_active_screen(const wmWindow *win)
 }
 void WM_window_set_active_screen(wmWindow *win, WorkSpace *workspace, bScreen *screen)
 {
-  BKE_workspace_active_screen_set(win->workspace_hook, workspace, screen);
+  BKE_workspace_active_screen_set(win->workspace_hook, win->winid, workspace, screen);
 }
 
 bool WM_window_is_temp_screen(const wmWindow *win)