Markdown writer: fewer unneeded escapes for #.

See #6259.

src/Text/Pandoc/Writers/Markdown/Inline.hs

@@ -43,7 +43,11 @@ import Text.Pandoc.Writers.Markdown.Types (MarkdownVariant(..),
 -- | Escape special characters for Markdown.
 escapeText :: WriterOptions -> Text -> Text
 escapeText opts = T.pack . go . T.unpack
-  where
+ where
+  startsWithSpace (' ':_) = True
+  startsWithSpace ('\t':_) = True
+  startsWithSpace [] = True
+  startsWithSpace _ = False
   go [] = []
   go (c:cs) =
     case c of
@@ -59,7 +63,10 @@ escapeText opts = T.pack . go . T.unpack
                       | isAlphaNum d || d == '_' || d == '{'
                          -> '\\':'@':go cs
                     _ -> '@':go cs
-       _ | c `elem` ['\\','`','*','_','[',']','#'] ->
+       '#' | isEnabled Ext_space_in_atx_header opts
+           , startsWithSpace cs
+           -> '\\':'#':go cs
+       _ | c `elem` ['\\','`','*','_','[',']'] ->
               '\\':c:go cs
        '|' | isEnabled Ext_pipe_tables opts -> '\\':'|':go cs
        '^' | isEnabled Ext_superscript opts -> '\\':'^':go cs
@@ -81,6 +88,8 @@ escapeText opts = T.pack . go . T.unpack
                   | isEnabled Ext_intraword_underscores opts
                   , isAlphaNum c
                   , isAlphaNum x -> c : '_' : x : go xs
+                '#':xs           -> c : '#' : go xs
+                '>':xs           -> c : '>' : go xs
                 _                -> c : go cs
 
 attrsToMarkdown :: Attr -> Doc Text

test/command/3792.md

@@ -6,7 +6,7 @@ and properly escaped.
 ok
 ^D
 ---
-title: \<this\> \*that\*
+title: \<this> \*that\*
 ---
 
 ok

test/command/4164.md

@@ -26,6 +26,6 @@ Here is inline html:
 
 Here is inline html:
 
-\<div\> \<balise\> bla bla \</div\>
+\<div> \<balise> bla bla \</div>
 
 ```

test/command/7208.md

@@ -2,5 +2,5 @@
 % pandoc -t gfm
 \<hi\>
 ^D
-\<hi\>
+\<hi>
 ```

test/command/biblatex-sigfridsson.md

@@ -90,7 +90,7 @@ references:
   - family: Ryde
     given: Ulf
   container-title: Journal of Computational Chemistry
-  doi: "10.1002/(SICI)1096-987X(199803)19:4\\<377::AID-JCC1\\>3.0.CO;2-P"
+  doi: "10.1002/(SICI)1096-987X(199803)19:4\\<377::AID-JCC1>3.0.CO;2-P"
   id: sigfridsson
   issue: 4
   issued: 1998

test/writer.opml

@@ -52,7 +52,7 @@
 </outline>
 <outline text="LaTeX" _note="-   &#10;-   2 + 2 = 4&#10;-   *x* ∈ *y*&#10;-   *α* ∧ *ω*&#10;-   223&#10;-   *p*-Tree&#10;-   Here’s some display math:&#10;    $$\\frac{d}{dx}f(x)=\\lim\_{h\\to 0}\\frac{f(x+h)-f(x)}{h}$$&#10;-   Here’s one that has a line break in it: *α* + *ω* × *x*².&#10;&#10;These shouldn’t be math:&#10;&#10;-   To get the famous equation, write `$e = mc^2$`.&#10;-   $22,000 is a *lot* of money. So is $34,000. (It worked if “lot” is&#10;    emphasized.)&#10;-   Shoes ($20) and socks ($5).&#10;-   Escaped `$`: $73 *this should be emphasized* 23$.&#10;&#10;Here’s a LaTeX table:&#10;&#10;------------------------------------------------------------------------">
 </outline>
-<outline text="Special Characters" _note="Here is some unicode:&#10;&#10;-   I hat: Î&#10;-   o umlaut: ö&#10;-   section: §&#10;-   set membership: ∈&#10;-   copyright: ©&#10;&#10;AT&amp;T has an ampersand in their name.&#10;&#10;AT&amp;T is another way to write it.&#10;&#10;This &amp; that.&#10;&#10;4 &amp;lt; 5.&#10;&#10;6 &amp;gt; 5.&#10;&#10;Backslash: \\&#10;&#10;Backtick: \`&#10;&#10;Asterisk: \*&#10;&#10;Underscore: \_&#10;&#10;Left brace: {&#10;&#10;Right brace: }&#10;&#10;Left bracket: \[&#10;&#10;Right bracket: \]&#10;&#10;Left paren: (&#10;&#10;Right paren: )&#10;&#10;Greater-than: &amp;gt;&#10;&#10;Hash: \#&#10;&#10;Period: .&#10;&#10;Bang: !&#10;&#10;Plus: +&#10;&#10;Minus: -&#10;&#10;------------------------------------------------------------------------">
+<outline text="Special Characters" _note="Here is some unicode:&#10;&#10;-   I hat: Î&#10;-   o umlaut: ö&#10;-   section: §&#10;-   set membership: ∈&#10;-   copyright: ©&#10;&#10;AT&amp;T has an ampersand in their name.&#10;&#10;AT&amp;T is another way to write it.&#10;&#10;This &amp; that.&#10;&#10;4 &amp;lt; 5.&#10;&#10;6 &amp;gt; 5.&#10;&#10;Backslash: \\&#10;&#10;Backtick: \`&#10;&#10;Asterisk: \*&#10;&#10;Underscore: \_&#10;&#10;Left brace: {&#10;&#10;Right brace: }&#10;&#10;Left bracket: \[&#10;&#10;Right bracket: \]&#10;&#10;Left paren: (&#10;&#10;Right paren: )&#10;&#10;Greater-than: &amp;gt;&#10;&#10;Hash: #&#10;&#10;Period: .&#10;&#10;Bang: !&#10;&#10;Plus: +&#10;&#10;Minus: -&#10;&#10;------------------------------------------------------------------------">
 </outline>
 <outline text="Links">
   <outline text="Explicit" _note="Just a [URL](/url/).&#10;&#10;[URL and title](/url/ &quot;title&quot;).&#10;&#10;[URL and title](/url/ &quot;title preceded by two spaces&quot;).&#10;&#10;[URL and title](/url/ &quot;title preceded by a tab&quot;).&#10;&#10;[URL and title](/url/ &quot;title with &quot;quotes&quot; in it&quot;)&#10;&#10;[URL and title](/url/ &quot;title with single quotes&quot;)&#10;&#10;[with\_underscore](/url/with_underscore)&#10;&#10;[Email link](mailto:nobody@nowhere.net)&#10;&#10;[Empty]().">