Fix for the default internal connect function for nodes (used in muting, detaching, etc.). This is supposed to look for the first input/output of every socket type, but was actually taking the first matching link from the link list, regardless of the linked socket's position.

source/blender/nodes/intern/node_util.c

@@ -29,6 +29,7 @@
  *  \ingroup nodes
  */
 
+#include <limits.h>
 
 #include "DNA_action_types.h"
 #include "DNA_node_types.h"
@@ -116,24 +117,41 @@ ListBase node_internal_connect_default(bNodeTree *ntree, bNode *node)
 		return ret;
 
 	for (datatype=0; datatype < NUM_SOCKET_TYPES; ++datatype) {
-		bNodeSocket *fromsock=NULL, *tosock=NULL;
+		bNodeSocket *fromsock, *tosock;
+		int fromindex, toindex;
 		bNodeLink *link;
 		
 		/* Connect the first input of each type with outputs of the same type. */
 		
+		fromindex = INT_MAX;
+		fromsock = NULL;
 		for (link=ntree->links.first; link; link=link->next) {
 			if (link->tonode == node && link->tosock->type == datatype) {
+				int index = BLI_findindex(&node->inputs, link->tosock);
+				if (index < fromindex) {
+					fromindex = index;
 					fromsock = link->tosock;
+				}
+			}
+		}
+		if (fromsock) {
 			++num_links_in;
 			if (!fromsock_first)
 				fromsock_first = fromsock;
-				break;
-			}
 		}
 		
+		toindex = INT_MAX;
+		tosock = NULL;
 		for (link=ntree->links.first; link; link=link->next) {
 			if (link->fromnode == node && link->fromsock->type == datatype) {
+				int index = BLI_findindex(&node->outputs, link->fromsock);
+				if (index < toindex) {
+					toindex = index;
 					tosock = link->fromsock;
+				}
+			}
+		}
+		if (tosock) {
 			++num_links_out;
 			if (!tosock_first)
 				tosock_first = tosock;
@@ -152,7 +170,6 @@ ListBase node_internal_connect_default(bNodeTree *ntree, bNode *node)
 			}
 		}
 	}
-	}
 	
 	/* if there is one input and one output link, but no reconnections by type,
 	 * simply connect those two sockets.