From cefeed6a005625648477874903fb4223aa7fbb1b Mon Sep 17 00:00:00 2001
From: Mark Fitzgerald <markfitzgerald@khanacademy.org>
Date: Tue, 4 Feb 2025 13:48:00 -0800
Subject: [PATCH] [bugfix/LEMS-2805-blockquote-hidden-in-explanation-on-mobile]
 Add a comment to clarify "parentElement" usage.

---
 packages/perseus/src/components/zoomable.tsx | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/perseus/src/components/zoomable.tsx b/packages/perseus/src/components/zoomable.tsx
index 5391d2ceba..95f007e745 100644
--- a/packages/perseus/src/components/zoomable.tsx
+++ b/packages/perseus/src/components/zoomable.tsx
@@ -197,6 +197,9 @@ class Zoomable extends React.Component<Props, State> {
         let parentNode = this._node;
         let currentNode: HTMLElement | null = parentNode;
         while (currentNode && currentNode.offsetWidth === 0) {
+            // When traversing up the DOM tree, we need to start at the "parentElement"
+            //      because "closest()" can match the current element,
+            //      and if it does so, then we are stuck in an infinite loop.
             currentNode =
                 currentNode.parentElement?.closest(".perseus-renderer") ?? null;
         }