Merge pull request #5127 from mathbraga/bug/5059_fix_external_connect…

…ion_after_updating_edges

Bug/5059 fix external connection after updating edges

cypress/integration/rendering/flowchart-v2.spec.js

@@ -741,6 +741,25 @@ A ~~~ B
     );
   });
 
+  it('5059: Should render when subgraph contains only subgraphs, has link to outside and itself is part of a link', () => {
+    imgSnapshotTest(
+      `flowchart
+
+      subgraph Main
+        subgraph Child1
+          Node1
+          Node2
+        end
+        subgraph Child2
+          Node3
+          Node4
+        end
+      end
+      Main --> Out1
+      Child2 --> Out2`
+    );
+  });
+
   describe('Markdown strings flowchart (#4220)', () => {
     describe('html labels', () => {
       it('With styling and classes', () => {

packages/mermaid/src/dagre-wrapper/mermaid-graphlib.js

@@ -254,6 +254,16 @@ export const adjustClustersAndEdges = (graph, depth) => {
     }
   });
 
+  for (let id of Object.keys(clusterDb)) {
+    const nonClusterChild = clusterDb[id].id;
+    const parent = graph.parent(nonClusterChild);
+
+    // Change replacement node of id to parent of current replacement node if valid
+    if (parent !== id && clusterDb[parent] && !clusterDb[parent].externalConnections) {
+      clusterDb[id].id = parent;
+    }
+  }
+
   // For clusters with incoming and/or outgoing edges translate those edges to a real node
   // in the cluster in order to fake the edge
   graph.edges().forEach(function (e) {
@@ -307,9 +317,13 @@ export const adjustClustersAndEdges = (graph, depth) => {
       w = getAnchorId(e.w);
       graph.removeEdge(e.v, e.w, e.name);
       if (v !== e.v) {
+        const parent = graph.parent(v);
+        clusterDb[parent].externalConnections = true;
         edge.fromCluster = e.v;
       }
       if (w !== e.w) {
+        const parent = graph.parent(w);
+        clusterDb[parent].externalConnections = true;
         edge.toCluster = e.w;
       }
       log.warn('Fix Replacing with XXX', v, w, e.name);