From 4e25bf5db9de8f673311e39673999adaf4be511b Mon Sep 17 00:00:00 2001
From: Knut Sveidqvist <knsv@sveido.com>
Date: Wed, 2 Oct 2024 21:06:01 +0200
Subject: [PATCH] Adding handling of self-loops into update position

---
 .../layout-algorithms/fixed/index.js              | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/packages/mermaid/src/rendering-util/layout-algorithms/fixed/index.js b/packages/mermaid/src/rendering-util/layout-algorithms/fixed/index.js
index 61f646024..fb7271793 100644
--- a/packages/mermaid/src/rendering-util/layout-algorithms/fixed/index.js
+++ b/packages/mermaid/src/rendering-util/layout-algorithms/fixed/index.js
@@ -94,6 +94,21 @@ const calcIntersections = (startNodeId, endNodeId, startNodeSize, endNodeSize) =
     const endIntersection = { x: endNodeSize.x, y: endNodeSize.x, pos: 'c' };
     return [startIntersection, endIntersection];
   }
+
+  // Check for self loop
+  if (startNodeId === endNodeId) {
+    const intersection = calcIntersectionPoint(startNode, {
+      x: startNode.x + startNode.width / 2 + 20,
+      y: startNode.y + startNode.height / 2,
+    });
+
+    const forthY = startNode.height / 4;
+    return [
+      { x: intersection.x, y: startNode.y - forthY, pos: 'r' },
+      { x: intersection.x, y: startNode.y + forthY, pos: 'r' },
+    ];
+  }
+
   const endNode = nodeDB.get(endNodeId);
   if (endNodeSize && endNode) {
     endNode.x = endNodeSize.x;