Fix T88588: crash when muting node with multi input socket

The bug existed before the new evaluator already, but the new evaluator
is more sensitive to this kind of error.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/nodes/intern/node_tree_ref.cc b/source/blender/nodes/intern/node_tree_ref.cc
index 5c0bc0b5ebc..8699736e543 100644
--- a/source/blender/nodes/intern/node_tree_ref.cc
+++ b/source/blender/nodes/intern/node_tree_ref.cc
@@ -297,6 +297,12 @@ void OutputSocketRef::foreach_logical_target(
       skipped_fn.call_safe(target);
       for (const InternalLinkRef *internal_link : target_node.internal_links()) {
         if (&internal_link->from() == &target) {
+          /* The internal link only forwards the first incoming link. */
+          if (target.is_multi_input_socket()) {
+            if (target.directly_linked_links()[0] != link) {
+              continue;
+            }
+          }
           const OutputSocketRef &mute_output = internal_link->to();
           skipped_fn.call_safe(target);
           skipped_fn.call_safe(mute_output);