LaTeX reader: disable ligatures inside \texttt.

Closes #10781.

src/Text/Pandoc/Readers/LaTeX.hs

@@ -343,6 +343,12 @@ inlineCommands = M.unions
   , biblatexInlineCommands tok
   , rest ]
  where
+  disableLigatures p = do
+    oldLigatures <- sLigatures <$> getState
+    updateState (\s -> s{ sLigatures = False })
+    res <- p
+    updateState (\s -> s{ sLigatures = oldLigatures })
+    pure res
   rest = M.fromList
     [ ("emph", extractSpaces emph <$> tok)
     , ("textit", extractSpaces emph <$> tok)
@@ -352,7 +358,7 @@ inlineCommands = M.unions
     , ("textmd", extractSpaces (spanWith ("",["medium"],[])) <$> tok)
     , ("textrm", extractSpaces (spanWith ("",["roman"],[])) <$> tok)
     , ("textup", extractSpaces (spanWith ("",["upright"],[])) <$> tok)
-    , ("texttt", formatCode nullAttr <$> tok)
+    , ("texttt", formatCode nullAttr <$> disableLigatures tok)
     , ("alert", skipopts >> spanWith ("",["alert"],[]) <$> tok) -- beamer
     , ("textsuperscript", extractSpaces superscript <$> tok)
     , ("textsubscript", extractSpaces subscript <$> tok)
@@ -634,6 +640,7 @@ inline = do
         do eatOneToken
            report $ ParsingUnescaped t pos
            return $ str t
+  ligatures <- sLigatures <$> getState
   case toktype of
     Comment     -> mempty <$ eatOneToken
     Spaces      -> space <$ eatOneToken
@@ -641,14 +648,19 @@ inline = do
     Word        -> str t <$ eatOneToken
     Symbol      ->
       case t of
-        "-"     -> eatOneToken *>
+        "-" | ligatures
+                -> eatOneToken *>
                     option (str "-") (symbol '-' *>
                       option (str "–") (str "—" <$ symbol '-'))
         "'"     -> eatOneToken *>
-                    option (str "’") (str  "”" <$ symbol '\'')
+                    option (str "’") (str  "”" <$ (guard ligatures *> symbol '\''))
         "~"     -> str "\160" <$ eatOneToken
-        "`"     -> doubleQuote <|> singleQuote <|> symbolAsString
-        "\""    -> doubleQuote <|> singleQuote <|> symbolAsString
+        "`" | ligatures
+                -> doubleQuote <|> singleQuote <|> (str "‘" <$ symbol '`')
+            | otherwise
+                -> str "‘" <$ symbol '`'
+        "\"" | ligatures
+                -> doubleQuote <|> singleQuote <|> symbolAsString
         "“"     -> doubleQuote <|> symbolAsString
         "‘"     -> singleQuote <|> symbolAsString
         "$"     -> dollarsMath <|> unescapedSymbolAsString

src/Text/Pandoc/Readers/LaTeX/Parsing.hs

@@ -173,6 +173,7 @@ data LaTeXState = LaTeXState{ sOptions       :: ReaderOptions
                             , sFileContents  :: M.Map Text Text
                             , sEnableWithRaw :: Bool
                             , sRawTokens     :: IntMap.IntMap [Tok]
+                            , sLigatures     :: Bool
                             }
      deriving Show
 
@@ -201,6 +202,7 @@ defaultLaTeXState = LaTeXState{ sOptions       = def
                               , sFileContents  = M.empty
                               , sEnableWithRaw = True
                               , sRawTokens     = IntMap.empty
+                              , sLigatures     = True
                               }
 
 instance PandocMonad m => HasQuoteContext LaTeXState m where

test/command/10781.md

@@ -0,0 +1,8 @@
+```
+% pandoc -f latex -t markdown --wrap=preserve
+This is \texttt{--flag} with dashes.
+This is the same --flag without a code.
+^D
+This is `--flag` with dashes.
+This is the same --flag without a code.
+```

test/command/3958.md

@@ -9,7 +9,7 @@
 % pandoc -f latex -t native
 \texttt{``hi''}
 ^D
-[ Para [ Code ( "" , [] , [] ) "\8220hi\8221" ] ]
+[ Para [ Code ( "" , [] , [] ) "\8216\8216hi\8217\8217" ] ]
 ```
 
 ```