Fix T102386: crash when trying to link sockets from different node trees

This was caused by rBc39eb09ae587e1d9. The optimization broke the case
when the socket is not in the provided node tree. Now there are two separate
functions, one that always does the slow check to see of the socket is really
in the node tree and a potentially much faster version when we are sure
that the socket is in the tree.

4 files changed, 20 insertions, 9 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 6eb9650348a..4e2fc55a222 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -746,7 +746,14 @@ struct bNode *nodeFindNodebyName(struct bNodeTree *ntree, const char *name);
 /**
  * Finds a node based on given socket and returns true on success.
  */
-bool nodeFindNode(struct bNodeTree *ntree,
+bool nodeFindNodeTry(struct bNodeTree *ntree,
+                     struct bNodeSocket *sock,
+                     struct bNode **r_node,
+                     int *r_sockindex);
+/**
+ * Same as above but expects that the socket definitely is in the node tree.
+ */
+void nodeFindNode(struct bNodeTree *ntree,
                   struct bNodeSocket *sock,
                   struct bNode **r_node,
                   int *r_sockindex);
diff --git a/source/blender/blenkernel/intern/node.cc b/source/blender/blenkernel/intern/node.cc
index eb0c78e9361..59c2769869d 100644
--- a/source/blender/blenkernel/intern/node.cc
+++ b/source/blender/blenkernel/intern/node.cc
@@ -2019,7 +2019,7 @@ bNode *nodeFindNodebyName(bNodeTree *ntree, const char *name)
   return (bNode *)BLI_findstring(&ntree->nodes, name, offsetof(bNode, name));
 }
 
-bool nodeFindNode(bNodeTree *ntree, bNodeSocket *sock, bNode **r_node, int *r_sockindex)
+void nodeFindNode(bNodeTree *ntree, bNodeSocket *sock, bNode **r_node, int *r_sockindex)
 {
   *r_node = nullptr;
   if (!ntree->runtime->topology_cache_is_dirty) {
@@ -2029,9 +2029,15 @@ bool nodeFindNode(bNodeTree *ntree, bNodeSocket *sock, bNode **r_node, int *r_so
       ListBase *sockets = (sock->in_out == SOCK_IN) ? &node->inputs : &node->outputs;
       *r_sockindex = BLI_findindex(sockets, sock);
     }
-    return true;
+    return;
   }
+  const bool success = nodeFindNodeTry(ntree, sock, r_node, r_sockindex);
+  BLI_assert(success);
+  UNUSED_VARS_NDEBUG(success);
+}
 
+bool nodeFindNodeTry(bNodeTree *ntree, bNodeSocket *sock, bNode **r_node, int *r_sockindex)
+{
   LISTBASE_FOREACH (bNode *, node, &ntree->nodes) {
     ListBase *sockets = (sock->in_out == SOCK_IN) ? &node->inputs : &node->outputs;
     int i;
diff --git a/source/blender/editors/interface/interface_ops.cc b/source/blender/editors/interface/interface_ops.cc
index 2d06dd2c465..1b576583291 100644
--- a/source/blender/editors/interface/interface_ops.cc
+++ b/source/blender/editors/interface/interface_ops.cc
@@ -1165,7 +1165,7 @@ bool UI_context_copy_to_selected_list(bContext *C,
     if (RNA_struct_is_a(ptr->type, &RNA_NodeSocket)) {
       bNodeTree *ntree = (bNodeTree *)ptr->owner_id;
       bNodeSocket *sock = static_cast<bNodeSocket *>(ptr->data);
-      if (nodeFindNode(ntree, sock, &node, nullptr)) {
+      if (nodeFindNodeTry(ntree, sock, &node, nullptr)) {
         if ((path = RNA_path_resolve_from_type_to_property(ptr, prop, &RNA_Node)) != nullptr) {
           /* we're good! */
         }
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 14122ddb878..c6115711c1a 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -1302,8 +1302,8 @@ static bNodeLink *rna_NodeTree_link_new(bNodeTree *ntree,
     return NULL;
   }
 
-  nodeFindNode(ntree, fromsock, &fromnode, NULL);
-  nodeFindNode(ntree, tosock, &tonode, NULL);
+  nodeFindNodeTry(ntree, fromsock, &fromnode, NULL);
+  nodeFindNodeTry(ntree, tosock, &tonode, NULL);
   /* check validity of the sockets:
    * if sockets from different trees are passed in this will fail!
    */
@@ -2789,9 +2789,7 @@ static char *rna_NodeSocket_path(const PointerRNA *ptr)
   int socketindex;
   char name_esc[sizeof(node->name) * 2];
 
-  if (!nodeFindNode(ntree, sock, &node, &socketindex)) {
-    return NULL;
-  }
+  nodeFindNode(ntree, sock, &node, &socketindex);
 
   BLI_str_escape(name_esc, node->name, sizeof(name_esc));