Fix T76033: VSE crash with prefetch, disk cache and meta strips

`BKE_sequencer_prefetch_get_original_sequence()` didn't look in metas
and returned NULL. This caused crash in disk cache that was trying to
read seq->name.

Add function that will look in meta strips recursively and condition
that seq must not be NULL.

Reviewed By: brecht

Maniphest Tasks: T76033

Differential Revision: https://developer.blender.org/D7597

1 files changed, 8 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/seqcache.c b/source/blender/blenkernel/intern/seqcache.c
index f999a98faac..8a8b4d98c63 100644
--- a/source/blender/blenkernel/intern/seqcache.c
+++ b/source/blender/blenkernel/intern/seqcache.c
@@ -1225,6 +1225,10 @@ struct ImBuf *BKE_sequencer_cache_get(
     seq = BKE_sequencer_prefetch_get_original_sequence(seq, scene);
   }
 
+  if (!seq) {
+    return NULL;
+  }
+
   if (!scene->ed->cache) {
     seq_cache_create(context->bmain, scene);
   }
@@ -1287,6 +1291,10 @@ bool BKE_sequencer_cache_put_if_possible(const SeqRenderData *context,
     seq = BKE_sequencer_prefetch_get_original_sequence(seq, scene);
   }
 
+  if (!seq) {
+    return NULL;
+  }
+
   if (BKE_sequencer_cache_recycle_item(scene)) {
     BKE_sequencer_cache_put(context, seq, cfra, type, ibuf, cost, skip_disk_cache);
     return true;