Fix T90646: VSE hangs when strips overlap

When all strips are selected and overlap is caused, this causes VSE to
hang in infinite loop, because such situation should never happen.

To prevent infinite loop, ensure, that strip overlap is not tested
against single overlapping strip itself.

Prevent overlap that can not be handled because of issue described above
by moving overlapping strip between channels.

Reviewed By: campbellbarton

Differential Revision: D12209

1 files changed, 7 insertions, 8 deletions

diff --git a/source/blender/editors/transform/transform_convert_sequencer.c b/source/blender/editors/transform/transform_convert_sequencer.c
index 17512c79d03..45ed0f3b664 100644
--- a/source/blender/editors/transform/transform_convert_sequencer.c
+++ b/source/blender/editors/transform/transform_convert_sequencer.c
@@ -400,15 +400,14 @@ static void seq_transform_handle_overlap(TransInfo *t, SeqCollection *transforme
   if (seq_transform_check_strip_effects(transformed_strips)) {
     /* Update effect strips based on strips just moved in time. */
     seq_transform_update_effects(t, transformed_strips);
+  }
 
-    /* If any effects still overlap, we need to move them up. */
-    Sequence *seq;
-    SEQ_ITERATOR_FOREACH (seq, transformed_strips) {
-      if ((seq->type & SEQ_TYPE_EFFECT) && seq->seq1) {
-        if (SEQ_transform_test_overlap(seqbasep, seq)) {
-          SEQ_transform_seqbase_shuffle(seqbasep, seq, t->scene);
-        }
-      }
+  /* If any effects still overlap, we need to move them up.
+   * In some cases other strips can be overlapping still, see T90646. */
+  Sequence *seq;
+  SEQ_ITERATOR_FOREACH (seq, transformed_strips) {
+    if (SEQ_transform_test_overlap(seqbasep, seq)) {
+      SEQ_transform_seqbase_shuffle(seqbasep, seq, t->scene);
     }
   }
 }