Fix T98925: Editor panels are broken

Commit 277fa2f441f4 added channels region to unintended editors if sequencer was
used in area. This caused issues with some editors having 2 tool regions and
non functioning side panel.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D15253

3 files changed, 48 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_screen.h b/source/blender/blenkernel/BKE_screen.h
index 4dda21d99b8..3922bfb6c0d 100644
--- a/source/blender/blenkernel/BKE_screen.h
+++ b/source/blender/blenkernel/BKE_screen.h
@@ -440,6 +440,14 @@ void BKE_region_callback_free_gizmomap_set(void (*callback)(struct wmGizmoMap *)
 void BKE_region_callback_refresh_tag_gizmomap_set(void (*callback)(struct wmGizmoMap *));
 
 /**
+ * Find a region of type \a region_type in provided \a regionbase.
+ *
+ * \note this is useful for versioning where either the #Area or #SpaceLink regionbase are typical
+ * inputs
+ */
+struct ARegion *BKE_region_find_in_listbase_by_type(const struct ListBase *regionbase,
+                                                    const int region_type);
+/**
  * Find a region of type \a region_type in the currently active space of \a area.
  *
  * \note This does _not_ work if the region to look up is not in the active space.
diff --git a/source/blender/blenkernel/intern/screen.c b/source/blender/blenkernel/intern/screen.c
index ebc87c6ccc0..12dc1b6d1fa 100644
--- a/source/blender/blenkernel/intern/screen.c
+++ b/source/blender/blenkernel/intern/screen.c
@@ -856,6 +856,17 @@ void BKE_screen_remove_unused_scrverts(bScreen *screen)
 
 /* ***************** Utilities ********************** */
 
+ARegion *BKE_region_find_in_listbase_by_type(const ListBase *regionbase, const int region_type)
+{
+  LISTBASE_FOREACH (ARegion *, region, regionbase) {
+    if (region->regiontype == region_type) {
+      return region;
+    }
+  }
+
+  return NULL;
+}
+
 ARegion *BKE_area_find_region_type(const ScrArea *area, int region_type)
 {
   if (area) {
diff --git a/source/blender/blenloader/intern/versioning_300.c b/source/blender/blenloader/intern/versioning_300.c
index d2112e27836..bafbb7712ab 100644
--- a/source/blender/blenloader/intern/versioning_300.c
+++ b/source/blender/blenloader/intern/versioning_300.c
@@ -795,13 +795,16 @@ void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
             continue;
           }
           SpaceSeq *sseq = (SpaceSeq *)sl;
+          ListBase *regionbase = (sl == area->spacedata.first) ? &area->regionbase :
+                                                                 &sl->regionbase;
           sseq->flag |= SEQ_CLAMP_VIEW;
 
           if (ELEM(sseq->view, SEQ_VIEW_PREVIEW, SEQ_VIEW_SEQUENCE_PREVIEW)) {
             continue;
           }
 
-          ARegion *timeline_region = BKE_area_find_region_type(area, RGN_TYPE_WINDOW);
+          ARegion *timeline_region = BKE_region_find_in_listbase_by_type(regionbase,
+                                                                         RGN_TYPE_WINDOW);
 
           if (timeline_region == NULL) {
             continue;
@@ -2588,16 +2591,19 @@ void blo_do_versions_300(FileData *fd, Library *UNUSED(lib), Main *bmain)
 
           ListBase *regionbase = (sl == area->spacedata.first) ? &area->regionbase :
                                                                  &sl->regionbase;
-          ARegion *region = BKE_area_find_region_type(area, RGN_TYPE_CHANNELS);
+          ARegion *region = BKE_region_find_in_listbase_by_type(regionbase, RGN_TYPE_CHANNELS);
           if (!region) {
-            ARegion *tools_region = BKE_area_find_region_type(area, RGN_TYPE_TOOLS);
+            /* Find sequencer tools region. */
+            ARegion *tools_region = BKE_region_find_in_listbase_by_type(regionbase,
+                                                                        RGN_TYPE_TOOLS);
             region = do_versions_add_region(RGN_TYPE_CHANNELS, "channels region");
             BLI_insertlinkafter(regionbase, tools_region, region);
             region->alignment = RGN_ALIGN_LEFT;
             region->v2d.flag |= V2D_VIEWSYNC_AREA_VERTICAL;
           }
 
-          ARegion *timeline_region = BKE_area_find_region_type(area, RGN_TYPE_WINDOW);
+          ARegion *timeline_region = BKE_region_find_in_listbase_by_type(regionbase,
+                                                                         RGN_TYPE_WINDOW);
           if (timeline_region != NULL) {
             timeline_region->v2d.flag |= V2D_VIEWSYNC_AREA_VERTICAL;
           }
@@ -2775,5 +2781,24 @@ void blo_do_versions_300(FileData *fd, Library *UNUSED(lib), Main *bmain)
    */
   {
     /* Keep this block, even when empty. */
+
+    /* Fix for T98925 - remove channels region, that was initialized in incorrect editor types. */
+    for (bScreen *screen = bmain->screens.first; screen; screen = screen->id.next) {
+      LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+        LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
+          if (ELEM(sl->spacetype, SPACE_ACTION, SPACE_CLIP, SPACE_GRAPH, SPACE_NLA, SPACE_SEQ)) {
+            continue;
+          }
+
+          ListBase *regionbase = (sl == area->spacedata.first) ? &area->regionbase :
+                                                                 &sl->regionbase;
+          ARegion *channels_region = BKE_region_find_in_listbase_by_type(regionbase,
+                                                                         RGN_TYPE_CHANNELS);
+          if (channels_region) {
+            BLI_freelinkN(regionbase, channels_region);
+          }
+        }
+      }
+    }
   }
 }