From c36500ea4739f9bb2422fac35e2b8ded0e0c6d7d Mon Sep 17 00:00:00 2001
From: Benjamin Esham <bdesham@gmail.com>
Date: Mon, 5 Sep 2011 21:59:53 -0500
Subject: [PATCH] Fix incorrect treatment of backticks with only one character
 enclosed

Markdown treats spans as code if they are enclosed within single
backticks (e.g. `foo`). The regular expression used to detect these had
a corner case which would be triggered if there was only one character
in backticks (`a`): Vim would not see the the second backtick, and the
syntax region would not be properly closed. The solution was to make one
of the regular expression atoms zero-width.
---
 syntax/markdown.vim | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/syntax/markdown.vim b/syntax/markdown.vim
index b79de52b..aca7cf6b 100644
--- a/syntax/markdown.vim
+++ b/syntax/markdown.vim
@@ -36,12 +36,11 @@ syntax case ignore
 syntax sync linebreaks=1
 
 " Additions to HTML groups
-syntax region htmlBold    start=/\\\@<!\(^\|\A\)\@=\*\@<!\*\*\*\@!\S/  end=/\S\\\@<!\*\@<!\*\*\*\@!\($\|\A\)\@=/  contains=htmlItalic,@Spell
+syntax region htmlBold    start=/\\\@<!\(^\|\A\)\@=\*\@<!\*\*\*\@!\S\@=/  end=/\S\\\@<!\*\@<!\*\*\*\@!\($\|\A\)\@=/  contains=htmlItalic,@Spell
 
-
-syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\*\@<!\*\*\@!\S/    end=/\S\\\@<!\*\@<!\*\*\@!\($\|\A\)\@=/    contains=htmlBold,@Spell
-syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\<_\@<!___\@!\S/      end=/\S\\\@<!_\@<!___\@!\($\|\A\)\@=/       contains=htmlBold,@Spell
-syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\<_\@<!__\@!\S/       end=/\S\\\@<!_\@<!__\@!\($\|\A\)\@=/       contains=htmlBold,@Spell
+syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\*\@<!\*\*\@!\S\@=/   end=/\S\\\@<!\*\@<!\*\*\@!\($\|\A\)\@=/    contains=htmlBold,@Spell
+syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\<_\@<!___\@!\S\@=/   end=/\S\\\@<!_\@<!___\@!\($\|\A\)\@=/       contains=htmlBold,@Spell
+syntax region htmlItalic  start=/\\\@<!\(^\|\A\)\@=\<_\@<!__\@!\S\@=/    end=/\S\\\@<!_\@<!__\@!\($\|\A\)\@=/       contains=htmlBold,@Spell
 
 " [link](URL) | [link][id] | [link][]
 syntax region mkdLink matchgroup=mkdDelimiter start="\!\?\["  end="\]\ze\s*[[(]" contains=@Spell nextgroup=mkdURL,mkdID skipwhite
@@ -68,8 +67,8 @@ syntax match  mkdListItem  /^\s*\d\+\.\s\+.*\n\(\(^.\+\n\)*\n\?\)\(\(^\(\s\{4}\|
 "
 syntax match  mkdBlockCode  /^\s*\n\(^\(\s\{4}\|\t\).*\n\)\+/
 syntax match  mkdListCode   /^\s*\n\(^\(\s\{8}\|\t{2}\).*\n\)\+/
-syntax match  mkdLineBreak /  \+$/
-syntax region mkdCode       start=/\\\@<!`/     end=/\\\@<!`/
+syntax match  mkdLineBreak  /  \+$/
+syntax region mkdCode       start=/\\\@<!`[^`]\@=/     end=/\\\@<![^`]`/
 syntax region mkdCode       start=/\s*``[^`]*/  end=/[^`]*``\s*/
 syntax region mkdBlockquote start=/^\s*>/       end=/$/           contains=mkdLineBreak,mkdLineContinue,@Spell
 syntax region mkdCode       start="<pre[^>]*>"  end="</pre>"