From 31a798ff212c21c0713fbb0948f0e3dba4daa475 Mon Sep 17 00:00:00 2001
From: Erik Demaine <edemaine@mit.edu>
Date: Fri, 13 Oct 2023 13:42:18 -0400
Subject: [PATCH] Fix multiple $math$ chunks connected only by punctuation (fix
 #636)

---
 CHANGELOG.md       | 5 +++++
 lib/formats.coffee | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf8a9a3..a0aca81 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ To see every change with descriptions aimed at developers, see
 As a continuously updated web app, Coauthor uses dates
 instead of version numbers.
 
+## 2023-10-13
+
+* Fix multiple \$math\$ chunks connected only by punctuation
+  [[#636](https://github.com/edemaine/coauthor/issues/636)]
+
 ## 2023-10-12
 
 * Superusers can now start private threads (e.g. for course staff discussion)
diff --git a/lib/formats.coffee b/lib/formats.coffee
index dc493bb..64f60c7 100644
--- a/lib/formats.coffee
+++ b/lib/formats.coffee
@@ -572,12 +572,14 @@ formats =
     [text, ticks] = preprocessMarkdownTicks text
     ## Support what we can of LaTeX before doing Markdown conversion.
     [text, math] = latex2htmlLight text, me
+    #console.log text, math
     ## Put Markdown verbatims back in.
     text = putTicksBack text, ticks
     if title  ## use "single-line" version of Markdown
       text = markdownInline text
     else
       text = markdown text
+    #console.log 'markdown', text
     ## Convert <ol start=...> output from Markdown to CSS-compatible reset.
     text = text.replace /<ol start="([\d+])">/ig, (match, start) ->
       """<ol style="counter-reset: enum #{-1 + parseInt start}">"""
@@ -761,6 +763,7 @@ postprocessKaTeX = (text, math, initialBold) ->
     !MATH(\d+)ENDMATH!
     ([,.!?:;'"\-)\]}]*) # right puncutation to pull into math mode
     (?! -?> ) # prevent accidentally grabbing some of --> (end of HTML comment)
+    (?! MATH ) # prevent accidentally grabbing part of !MATH
     | ## Detect math within bold mode:
     <span([^<>]*)> |
     <b\b |