Update Mermaid to 8.1.0

This fixes dotted lines not rendering when the htmlLabels setting is
false (https://github.com/knsv/mermaid/pull/828).

Full list of changes: https://github.com/knsv/mermaid/releases

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/60869

1 files changed, 8 insertions, 0 deletions

diff --git a/app/assets/javascripts/behaviors/markdown/render_mermaid.js b/app/assets/javascripts/behaviors/markdown/render_mermaid.js
index d0b7f3ff7a2..b23de36f860 100644
--- a/app/assets/javascripts/behaviors/markdown/render_mermaid.js
+++ b/app/assets/javascripts/behaviors/markdown/render_mermaid.js
@@ -59,6 +59,14 @@ export default function renderMermaid($els) {
         mermaid.init(undefined, el, id => {
           const svg = document.getElementById(id);
 
+          // As of https://github.com/knsv/mermaid/commit/57b780a0d,
+          // Mermaid will make two init callbacks:one to initialize the
+          // flow charts, and another to initialize the Gannt charts.
+          // Guard against an error caused by double initialization.
+          if (svg.classList.contains('mermaid')) {
+            return;
+          }
+
           svg.classList.add('mermaid');
 
           // pre > code > svg