From 984768fa85ff8ce2d5ef18311a013a66bfecfd42 Mon Sep 17 00:00:00 2001
From: Saul Shanabrook <s.shanabrook@gmail.com>
Date: Sun, 11 Nov 2018 10:23:05 -0500
Subject: [PATCH] Skip processing svg anchor elements

Fixes https://github.com/jupyterlab/jupyterlab/issues/5589 by skipping
processing of a elements that are not `HTMLAnchorElement`s, including
those within SVG elements. Currently, if you have a `a` element
inside an SVG element it will break HTML rendering since that element
does not have a `href` like other `a` elements do.
---
 packages/rendermime/src/renderers.ts | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/rendermime/src/renderers.ts b/packages/rendermime/src/renderers.ts
index 61fb275ca931..d7cabcd03acc 100644
--- a/packages/rendermime/src/renderers.ts
+++ b/packages/rendermime/src/renderers.ts
@@ -628,15 +628,21 @@ namespace Private {
     // Handle anchor elements.
     let anchors = node.getElementsByTagName('a');
     for (let i = 0; i < anchors.length; i++) {
-      let path = anchors[i].href || '';
+      const el = anchors[i];
+      // skip when processing a elements inside svg
+      // which are of type SVGAnimatedString
+      if (!(el instanceof HTMLAnchorElement)) {
+        continue;
+      }
+      let path = el.href;
       const isLocal =
         resolver && resolver.isLocal
           ? resolver.isLocal(path)
           : URLExt.isLocal(path);
       if (isLocal) {
-        anchors[i].target = '_self';
+        el.target = '_self';
       } else {
-        anchors[i].target = '_blank';
+        el.target = '_blank';
       }
     }