Screen: simplify internal logic for new full-screen areas

Creating a new full screen area had it's area initialized as empty,
updating the screen then set the area to a 3D view (as a fallback),
before the actual area type was set.

This made setting the intended space-type run the 3D views exit callback
on a 3D view without a View3D struct allocated, which the exit callback
needed to account for.

Resolve by calling ED_screen_change after the area type has been set.

3 files changed, 17 insertions, 11 deletions

diff --git a/source/blender/editors/include/ED_screen.h b/source/blender/editors/include/ED_screen.h
index bdd7ec571dc..addc3628f9e 100644
--- a/source/blender/editors/include/ED_screen.h
+++ b/source/blender/editors/include/ED_screen.h
@@ -215,7 +215,7 @@ void ED_screen_restore_temp_type(struct bContext *C, ScrArea *area);
 ScrArea *ED_screen_full_newspace(struct bContext *C, ScrArea *area, int type);
 void ED_screen_full_prevspace(struct bContext *C, ScrArea *area);
 void ED_screen_full_restore(struct bContext *C, ScrArea *area);
-ScrArea *ED_screen_state_maximized_create(struct bContext *C);
+bScreen *ED_screen_state_maximized_create(struct bContext *C);
 struct ScrArea *ED_screen_state_toggle(struct bContext *C,
                                        struct wmWindow *win,
                                        struct ScrArea *area,
diff --git a/source/blender/editors/screen/screen_edit.c b/source/blender/editors/screen/screen_edit.c
index 6cb184a3394..bcfe30a829e 100644
--- a/source/blender/editors/screen/screen_edit.c
+++ b/source/blender/editors/screen/screen_edit.c
@@ -1275,11 +1275,14 @@ void ED_screen_scene_change(bContext *C, wmWindow *win, Scene *scene)
 
 ScrArea *ED_screen_full_newspace(bContext *C, ScrArea *area, int type)
 {
+  bScreen *newscreen = NULL;
   ScrArea *newsa = NULL;
   SpaceLink *newsl;
 
   if (!area || area->full == NULL) {
-    newsa = ED_screen_state_maximized_create(C);
+    newscreen = ED_screen_state_maximized_create(C);
+    newsa = newscreen->areabase.first;
+    BLI_assert(newsa->spacetype == SPACE_EMPTY);
   }
 
   if (!newsa) {
@@ -1296,6 +1299,10 @@ ScrArea *ED_screen_full_newspace(bContext *C, ScrArea *area, int type)
 
   ED_area_newspace(C, newsa, type, (newsl && newsl->link_flag & SPACE_FLAG_TYPE_TEMPORARY));
 
+  if (newscreen) {
+    ED_screen_change(C, newscreen);
+  }
+
   return newsa;
 }
 
@@ -1361,6 +1368,10 @@ void ED_screen_full_restore(bContext *C, ScrArea *area)
  * \param toggle_area: If this is set, its space data will be swapped with the one of the new empty
  *                     area, when toggling back it can be swapped back again.
  * \return The newly created screen with the non-normal area.
+ *
+ * \note The caller must run #ED_screen_change this is not done in this function
+ * as it would attempt to initialize areas that don't yet have a space-type assigned
+ * (converting them to 3D view without creating the space-data).
  */
 static bScreen *screen_state_to_nonnormal(bContext *C,
                                           wmWindow *win,
@@ -1429,7 +1440,6 @@ static bScreen *screen_state_to_nonnormal(bContext *C,
   }
   newa->full = oldscreen;
 
-  ED_screen_change(C, screen);
   ED_area_tag_refresh(newa);
 
   return screen;
@@ -1442,10 +1452,9 @@ static bScreen *screen_state_to_nonnormal(bContext *C,
  * Use this to just create a new maximized screen/area, rather than maximizing an existing one.
  * Otherwise, maximize with #ED_screen_state_toggle().
  */
-ScrArea *ED_screen_state_maximized_create(bContext *C)
+bScreen *ED_screen_state_maximized_create(bContext *C)
 {
-  bScreen *screen = screen_state_to_nonnormal(C, CTX_wm_window(C), NULL, SCREENMAXIMIZED);
-  return screen->areabase.first;
+  return screen_state_to_nonnormal(C, CTX_wm_window(C), NULL, SCREENMAXIMIZED);
 }
 
 /**
@@ -1548,6 +1557,8 @@ ScrArea *ED_screen_state_toggle(bContext *C, wmWindow *win, ScrArea *area, const
     }
 
     screen = screen_state_to_nonnormal(C, win, toggle_area, state);
+
+    ED_screen_change(C, screen);
   }
 
   BLI_assert(CTX_wm_screen(C) == screen);
diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index d560c1f9978..f17cee8056f 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -352,11 +352,6 @@ static void view3d_exit(wmWindowManager *UNUSED(wm), ScrArea *area)
 {
   BLI_assert(area->spacetype == SPACE_VIEW3D);
   View3D *v3d = area->spacedata.first;
-  /* Happens when freeing. */
-  if (v3d == NULL) {
-    return;
-  }
-
   MEM_SAFE_FREE(v3d->runtime.local_stats);
 }