Fix T101622: Sequencer channels not updating while panning view

`V2D_VIEWSYNC_AREA_VERTICAL` flag was mistakenly set to the sequencer
toolbar region instead of the channels region.

Reviewed By: ISS

Differential Revision: https://developer.blender.org/D16155

3 files changed, 25 insertions, 2 deletions

diff --git a/source/blender/blenkernel/BKE_blender_version.h b/source/blender/blenkernel/BKE_blender_version.h
index 96df8f7a443..806fff2099e 100644
--- a/source/blender/blenkernel/BKE_blender_version.h
+++ b/source/blender/blenkernel/BKE_blender_version.h
@@ -25,7 +25,7 @@ extern "C" {
 
 /* Blender file format version. */
 #define BLENDER_FILE_VERSION BLENDER_VERSION
-#define BLENDER_FILE_SUBVERSION 4
+#define BLENDER_FILE_SUBVERSION 5
 
 /* 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
diff --git a/source/blender/blenloader/intern/versioning_300.cc b/source/blender/blenloader/intern/versioning_300.cc
index e2b98b2283f..a2bd7fd2fd1 100644
--- a/source/blender/blenloader/intern/versioning_300.cc
+++ b/source/blender/blenloader/intern/versioning_300.cc
@@ -3630,6 +3630,29 @@ void blo_do_versions_300(FileData *fd, Library * /*lib*/, Main *bmain)
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 304, 5)) {
+    /* Fix for T101622 - update flags of sequence editor regions that were not initialized
+     * properly. */
+    LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
+      LISTBASE_FOREACH (ScrArea *, area, &screen->areabase) {
+        LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
+          ListBase *regionbase = (sl == area->spacedata.first) ? &area->regionbase :
+                                                                 &sl->regionbase;
+          if (sl->spacetype == SPACE_SEQ) {
+            LISTBASE_FOREACH (ARegion *, region, regionbase) {
+              if (region->regiontype == RGN_TYPE_TOOLS) {
+                region->v2d.flag &= ~V2D_VIEWSYNC_AREA_VERTICAL;
+              }
+              if (region->regiontype == RGN_TYPE_CHANNELS) {
+                region->v2d.flag |= V2D_VIEWSYNC_AREA_VERTICAL;
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *
diff --git a/source/blender/editors/space_sequencer/space_sequencer.c b/source/blender/editors/space_sequencer/space_sequencer.c
index 8b6d37caa41..1d20926d16c 100644
--- a/source/blender/editors/space_sequencer/space_sequencer.c
+++ b/source/blender/editors/space_sequencer/space_sequencer.c
@@ -129,7 +129,6 @@ static SpaceLink *sequencer_create(const ScrArea *UNUSED(area), const Scene *sce
   region->regiontype = RGN_TYPE_TOOLS;
   region->alignment = RGN_ALIGN_LEFT;
   region->flag = RGN_FLAG_HIDDEN;
-  region->v2d.flag |= V2D_VIEWSYNC_AREA_VERTICAL;
 
   /* Channels. */
   region = MEM_callocN(sizeof(ARegion), "channels for sequencer");
@@ -137,6 +136,7 @@ static SpaceLink *sequencer_create(const ScrArea *UNUSED(area), const Scene *sce
   BLI_addtail(&sseq->regionbase, region);
   region->regiontype = RGN_TYPE_CHANNELS;
   region->alignment = RGN_ALIGN_LEFT;
+  region->v2d.flag |= V2D_VIEWSYNC_AREA_VERTICAL;
 
   /* Preview region. */
   /* NOTE: if you change values here, also change them in sequencer_init_preview_region. */