Fix: only follow first input of multi-input-socket when muted

Otherwise muting a Join Geometry node has no effect, when there
are multiple Join Geometry nodes in a row.

2 files changed, 10 insertions, 4 deletions

diff --git a/source/blender/nodes/NOD_derived_node_tree.hh b/source/blender/nodes/NOD_derived_node_tree.hh
index f1dbb2caf29..3529336baf6 100644
--- a/source/blender/nodes/NOD_derived_node_tree.hh
+++ b/source/blender/nodes/NOD_derived_node_tree.hh
@@ -132,7 +132,8 @@ class DInputSocket : public DSocket {
   DOutputSocket get_corresponding_group_node_output() const;
   Vector<DOutputSocket, 4> get_corresponding_group_input_sockets() const;
 
-  void foreach_origin_socket(FunctionRef<void(DSocket)> callback) const;
+  void foreach_origin_socket(FunctionRef<void(DSocket)> callback,
+                             const bool follow_only_first_incoming_link = false) const;
 };
 
 /* A (nullable) reference to an output socket and the context it is in. */
diff --git a/source/blender/nodes/intern/derived_node_tree.cc b/source/blender/nodes/intern/derived_node_tree.cc
index c5f267470fd..36c64b00f47 100644
--- a/source/blender/nodes/intern/derived_node_tree.cc
+++ b/source/blender/nodes/intern/derived_node_tree.cc
@@ -168,10 +168,15 @@ DInputSocket DOutputSocket::get_active_corresponding_group_output_socket() const
 /* Call the given callback for every "real" origin socket. "Real" means that reroutes, muted nodes
  * and node groups are handled by this function. Origin sockets are ones where a node gets its
  * inputs from. */
-void DInputSocket::foreach_origin_socket(FunctionRef<void(DSocket)> callback) const
+void DInputSocket::foreach_origin_socket(FunctionRef<void(DSocket)> callback,
+                                         const bool follow_only_first_incoming_link) const
 {
   BLI_assert(*this);
-  for (const OutputSocketRef *linked_socket : socket_ref_->as_input().linked_sockets()) {
+  Span<const OutputSocketRef *> linked_sockets_to_check = socket_ref_->as_input().linked_sockets();
+  if (follow_only_first_incoming_link) {
+    linked_sockets_to_check = linked_sockets_to_check.take_front(1);
+  }
+  for (const OutputSocketRef *linked_socket : linked_sockets_to_check) {
     const NodeRef &linked_node = linked_socket->node();
     DOutputSocket linked_dsocket{context_, linked_socket};
 
@@ -180,7 +185,7 @@ void DInputSocket::foreach_origin_socket(FunctionRef<void(DSocket)> callback) co
       for (const InternalLinkRef *internal_link : linked_node.internal_links()) {
         if (&internal_link->to() == linked_socket) {
           DInputSocket input_of_muted_node{context_, &internal_link->from()};
-          input_of_muted_node.foreach_origin_socket(callback);
+          input_of_muted_node.foreach_origin_socket(callback, true);
         }
       }
     }