Do not parse hard line breaks in fenced codeblock info

This change makes commonmark-hs act the same as most other CommonMark implementations I've tried (markdown-it, pulldown-cmark, goldmark, commonmark.js, GFM).
jgm · Oct 26, 2023 · d0d7762 · d0d7762
1 parent cf945af
commit d0d7762
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Showing 3 changed files with 18 additions and 2 deletions.
diff --git a/commonmark/src/Commonmark/Blocks.hs b/commonmark/src/Commonmark/Blocks.hs
@@ -52,7 +52,7 @@ where
 import           Commonmark.Tag
 import           Commonmark.TokParsers
 import           Commonmark.ReferenceMap
-import           Commonmark.Inlines        (pEscaped, pLinkDestination,
+import           Commonmark.Inlines        (pEscapedSymbol, pLinkDestination,
                                             pLinkLabel, pLinkTitle)
 import           Commonmark.Entity         (unEntity)
 import           Commonmark.Tokens
@@ -1042,7 +1042,7 @@ fencedCodeSpec = BlockSpec
              guard $ fencelength >= 3
              skipWhile (hasType Spaces)
              let infoTok = noneOfToks (LineEnd : [Symbol '`' | c == '`'])
-             info <- T.strip . unEntity <$> many (pEscaped <|> infoTok)
+             info <- T.strip . unEntity <$> many (pEscapedSymbol <|> infoTok)
              lookAhead $ void lineEnd <|> eof
 
              let infotoks = tokenize "info string" info

diff --git a/commonmark/src/Commonmark/Inlines.hs b/commonmark/src/Commonmark/Inlines.hs
@@ -24,6 +24,7 @@ module Commonmark.Inlines
   , pLinkDestination
   , pLinkTitle
   , pEscaped
+  , pEscapedSymbol
   , processEmphasis
   , processBrackets
   , pBacktickSpan
@@ -937,6 +938,12 @@ pEscaped = do
   bs <- symbol '\\'
   option bs $ satisfyTok asciiSymbol <|> lineEnd
 
+-- parses backslash + punctuation, but not backslashed newline
+pEscapedSymbol :: Monad m => ParsecT [Tok] s m Tok
+pEscapedSymbol = do
+  bs <- symbol '\\'
+  option bs $ satisfyTok asciiSymbol
+
 asciiSymbol :: Tok -> Bool
 asciiSymbol (Tok (Symbol c) _ _) = isAscii c
 asciiSymbol _                    = False

diff --git a/commonmark/test/regression.md b/commonmark/test/regression.md
@@ -210,3 +210,12 @@ Issue #114.
 .
 <p>*.*̀.</p>
 ````````````````````````````````
+
+Issue #115.
+```````````````````````````````` example
+~~~\
+x
+.
+<pre><code class="language-\">x
+</code></pre>
+````````````````````````````````