VSE: Fix assigning effect strip inputs

Partialy fixes T73828

Currently all 3 effect inputs were assigned even if not all 3 were used.
This causes problems with reassigning effects in python, because 3rd input is
not accessible.

This patch will only assign inputs that are necessary for effect to work
properly.

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D6868

1 files changed, 13 insertions, 0 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_edit.c b/source/blender/editors/space_sequencer/sequencer_edit.c
index 4a8bea11b41..cbc4d9e51f1 100644
--- a/source/blender/editors/space_sequencer/sequencer_edit.c
+++ b/source/blender/editors/space_sequencer/sequencer_edit.c
@@ -673,6 +673,14 @@ int seq_effect_find_selected(Scene *scene,
   *r_selseq2 = seq2;
   *r_selseq3 = seq3;
 
+  /* TODO(Richard): This function needs some refactoring, this is just quick hack for T73828. */
+  if (BKE_sequence_effect_get_num_inputs(type) < 3) {
+    *r_selseq3 = NULL;
+  }
+  if (BKE_sequence_effect_get_num_inputs(type) < 2) {
+    *r_selseq2 = NULL;
+  }
+
   return 1;
 }
 
@@ -2222,6 +2230,11 @@ static int sequencer_reassign_inputs_exec(bContext *C, wmOperator *op)
   Sequence *seq1, *seq2, *seq3, *last_seq = BKE_sequencer_active_get(scene);
   const char *error_msg;
 
+  if (BKE_sequence_effect_get_num_inputs(last_seq->type) != 0) {
+    BKE_report(op->reports, RPT_ERROR, "Cannot reassign inputs: strip has no inputs");
+    return OPERATOR_CANCELLED;
+  }
+
   if (!seq_effect_find_selected(
           scene, last_seq, last_seq->type, &seq1, &seq2, &seq3, &error_msg)) {
     BKE_report(op->reports, RPT_ERROR, error_msg);