From 1e7fe633e8a2122d4f71fb39fa2cfc1212828975 Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Thu, 26 Dec 2019 15:38:13 -0500
Subject: [PATCH 1/2] Update FindTeX to properly skip comments, even if they
 include unbalanced braces.  Resolves issue mathjax/MathJax#2271

---
 ts/input/tex/FindTeX.ts | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/ts/input/tex/FindTeX.ts b/ts/input/tex/FindTeX.ts
index ad40c3fb7..c8e45c0a0 100644
--- a/ts/input/tex/FindTeX.ts
+++ b/ts/input/tex/FindTeX.ts
@@ -154,7 +154,7 @@ export class FindTeX<N, T, D> extends AbstractFindMath<N, T, D> {
      * @return {RegExp}     The regular expression for the end delimiter
      */
     protected endPattern(end: string) {
-        return new RegExp(quotePattern(end) + '|\\\\(?:[a-zA-Z]|.)|[{}]', 'g');
+        return new RegExp(quotePattern(end) + '|\\\\(?:[a-zA-Z]|.)|[{}%]', 'g');
     }
 
     /**
@@ -180,11 +180,24 @@ export class FindTeX<N, T, D> extends AbstractFindMath<N, T, D> {
                 braces++;
             } else if (match[0] === '}' && braces) {
                 braces--;
+            } else if (match[0] === '%') {
+                pattern.lastIndex += this.skipComment(text.substr(pattern.lastIndex));
             }
         }
         return null;
     }
 
+    /**
+     * Skip a comment (without matching braces or other special characters)
+     *
+     * @param {string} text   The string containing the comment to skip
+     * @return {number}       The position of the string after the comment
+     */
+    protected skipComment(text: string) {
+        const match = text.match(/.*?[\n\r]/);
+        return match ? match[0].length : text.length;
+    }
+
     /**
      * Search a string for math delimited by one of the delimiter pairs,
      *   or by \begin{env}...\end{env}, or \eqref{...}, \ref{...}, \\, or \$.

From ef679bd71e37dc1f0bdc43faad8563b8b3d86a8a Mon Sep 17 00:00:00 2001
From: "Davide P. Cervone" <dpvc@union.edu>
Date: Tue, 31 Dec 2019 16:05:07 -0500
Subject: [PATCH 2/2] Simplify how comments are handled.

---
 ts/input/tex/FindTeX.ts | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/ts/input/tex/FindTeX.ts b/ts/input/tex/FindTeX.ts
index c8e45c0a0..2f73f1905 100644
--- a/ts/input/tex/FindTeX.ts
+++ b/ts/input/tex/FindTeX.ts
@@ -154,7 +154,7 @@ export class FindTeX<N, T, D> extends AbstractFindMath<N, T, D> {
      * @return {RegExp}     The regular expression for the end delimiter
      */
     protected endPattern(end: string) {
-        return new RegExp(quotePattern(end) + '|\\\\(?:[a-zA-Z]|.)|[{}%]', 'g');
+        return new RegExp(quotePattern(end) + '|\\\\(?:[a-zA-Z]|.)|[{}]|%.*(?:[\n\r]|$)', 'g');
     }
 
     /**
@@ -180,24 +180,13 @@ export class FindTeX<N, T, D> extends AbstractFindMath<N, T, D> {
                 braces++;
             } else if (match[0] === '}' && braces) {
                 braces--;
-            } else if (match[0] === '%') {
-                pattern.lastIndex += this.skipComment(text.substr(pattern.lastIndex));
+            } else if (match[0].substr(0) === '%') {
+                pattern.lastIndex += match[0].length;
             }
         }
         return null;
     }
 
-    /**
-     * Skip a comment (without matching braces or other special characters)
-     *
-     * @param {string} text   The string containing the comment to skip
-     * @return {number}       The position of the string after the comment
-     */
-    protected skipComment(text: string) {
-        const match = text.match(/.*?[\n\r]/);
-        return match ? match[0].length : text.length;
-    }
-
     /**
      * Search a string for math delimited by one of the delimiter pairs,
      *   or by \begin{env}...\end{env}, or \eqref{...}, \ref{...}, \\, or \$.