From 11f3cbdb36de6ca77db38b6512e2594b2dd84cd0 Mon Sep 17 00:00:00 2001
From: Knut Sveidqvist <knut.sveidqvist@ipiccolo.com>
Date: Fri, 30 Apr 2021 10:34:50 +0200
Subject: [PATCH] #1958 Handling multiple edges from and to the same node tuple

---
 cypress/integration/rendering/flowchart-v2.spec.js | 12 ++++++++++++
 cypress/platform/knsv.html                         | 11 +++--------
 src/dagre-wrapper/edges.js                         |  4 ++--
 src/diagrams/flowchart/flowRenderer-v2.js          | 14 +++++++++++++-
 4 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/cypress/integration/rendering/flowchart-v2.spec.js b/cypress/integration/rendering/flowchart-v2.spec.js
index acc42c68b..48d5e0e95 100644
--- a/cypress/integration/rendering/flowchart-v2.spec.js
+++ b/cypress/integration/rendering/flowchart-v2.spec.js
@@ -598,4 +598,16 @@ flowchart RL
       {htmlLabels: true, flowchart: {htmlLabels: true}, securityLevel: 'loose'}
     );
   });
+    it('74: Handle labels for multiple edges from and to the same couple of nodes', () => {
+    imgSnapshotTest(
+      `
+flowchart RL
+    subgraph one
+      a1 -- l1 --> a2
+      a1 -- l2 --> a2
+    end
+      `,
+      {htmlLabels: true, flowchart: {htmlLabels: true}, securityLevel: 'loose'}
+    );
+  });
 });
diff --git a/cypress/platform/knsv.html b/cypress/platform/knsv.html
index 37272f297..d6db4d0a7 100644
--- a/cypress/platform/knsv.html
+++ b/cypress/platform/knsv.html
@@ -56,16 +56,11 @@ flowchart TD
   linkStyle 0,1 color:orange, stroke: orange;
 </div>
       <div class="mermaid" style="width: 100%; height: 20%;">
-flowchart TB
+flowchart RL
     subgraph two
-    b1
+    a1 -- l1 --> a2
+    a1 -- l2 --> a2
     end
-    subgraph three
-    c2
-    end
-
-    three --> two
-    two --> c2
       </div>
 <div class="mermaid2" style="width: 100%; height: 20%;">
 flowchart TB
diff --git a/src/dagre-wrapper/edges.js b/src/dagre-wrapper/edges.js
index f15574535..c70b9732f 100644
--- a/src/dagre-wrapper/edges.js
+++ b/src/dagre-wrapper/edges.js
@@ -105,7 +105,7 @@ export const insertEdgeLabel = (elem, edge) => {
 };
 
 export const positionEdgeLabel = (edge, paths) => {
-  log.info('Moving label', edge.id, edge.label, edgeLabels[edge.id]);
+  log.info('Moving label abc78 ', edge.id, edge.label, edgeLabels[edge.id]);
   let path = paths.updatedPath ? paths.updatedPath : paths.originalPath;
   if (edge.label) {
     const el = edgeLabels[edge.id];
@@ -114,7 +114,7 @@ export const positionEdgeLabel = (edge, paths) => {
     if (path) {
       //   // debugger;
       const pos = utils.calcLabelPosition(path);
-      log.info('Moving label from (', x, ',', y, ') to (', pos.x, ',', pos.y, ')');
+      log.info('Moving label from (', x, ',', y, ') to (', pos.x, ',', pos.y, ') abc78');
       // x = pos.x;
       // y = pos.y;
     }
diff --git a/src/diagrams/flowchart/flowRenderer-v2.js b/src/diagrams/flowchart/flowRenderer-v2.js
index fe30599f3..d5fead9dd 100644
--- a/src/diagrams/flowchart/flowRenderer-v2.js
+++ b/src/diagrams/flowchart/flowRenderer-v2.js
@@ -174,7 +174,9 @@ export const addVertices = function(vert, g, svgId) {
  * @param {Object} g The graph object
  */
 export const addEdges = function(edges, g) {
+  log.info('abc78 edges = ', edges);
   let cnt = 0;
+  let linkIdCnt = {};
 
   let defaultStyle;
   let defaultLabelStyle;
@@ -189,7 +191,17 @@ export const addEdges = function(edges, g) {
     cnt++;
 
     // Identify Link
-    var linkId = 'L-' + edge.start + '-' + edge.end;
+    var linkIdBase = 'L-' + edge.start + '-' + edge.end;
+    // count the links from+to the same node to give unique id
+    if (typeof linkIdCnt[linkIdBase] === 'undefined') {
+      linkIdCnt[linkIdBase] = 0;
+      log.info('abc78 new entry', linkIdBase, linkIdCnt[linkIdBase]);
+    } else {
+      linkIdCnt[linkIdBase]++;
+      log.info('abc78 new entry', linkIdBase, linkIdCnt[linkIdBase]);
+    }
+    let linkId = linkIdBase + '-' + linkIdCnt[linkIdBase];
+    log.info('abc78 new link id to be used is', linkIdBase, linkId, linkIdCnt[linkIdBase]);
     var linkNameStart = 'LS-' + edge.start;
     var linkNameEnd = 'LE-' + edge.end;