Man writer: improvements to code and code blocks.

The aim here (see #9020) is to produce more standard and more
portable man pages.  To that end:

- We revert the fanciness introduced in #7506, which employs a
  custom font name V and a macro that makes this act like boldface
  in a terminal and monospace in other formats.  Unfortunately,
  this code uses a mechanism that is not portable (and does not
  work in mandoc).

- Instead of using V for inline code, we simply use CR.
  Note that `\f[CR]` is emitted instead of plain `\f[C]`,
  because there is no C font in man.  (This produces warnings
  in recent versions of groff.)

- For code blocks, we now use the `.EX` and `.EE` macros,
  together with `.IP` for spacing and indentation.  This gives
  more standard code that can be better interpreted e.g. by mandoc.

2 files changed, 8 insertions, 9 deletions

diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 794c5518a..fb05df1f7 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -131,14 +131,12 @@ blockToMan opts (Header level _ inlines) = do
   return $ nowrap $ literal heading <> contents
 blockToMan opts (CodeBlock _ str) = return $
   literal ".IP" $$
-  literal ".nf" $$
-  literal "\\f[C]" $$
+  literal ".EX" $$
   ((case T.uncons str of
     Just ('.',_) -> literal "\\&"
     _            -> mempty) <>
    literal (escString opts str)) $$
-  literal "\\f[R]" $$
-  literal ".fi"
+  literal ".EE"
 blockToMan opts (BlockQuote blocks) = do
   contents <- blockListToMan opts blocks
   return $ literal ".RS" $$ contents $$ literal ".RE"
@@ -291,8 +289,7 @@ inlineToMan opts (Quoted DoubleQuote lst) = do
 inlineToMan opts (Cite _ lst) =
   inlineListToMan opts lst
 inlineToMan opts (Code _ str) =
-  -- note that the V font is specially defined in the default man template
-  withFontFeature 'V' (return (literal $ escString opts str))
+  withFontFeature 'C' (return (literal $ escString opts str))
 inlineToMan opts (Str str@(T.uncons -> Just ('.',_))) =
   return $ afterBreak "\\&" <> literal (escString opts str)
 inlineToMan opts (Str str) = return $ literal $ escString opts str
diff --git a/src/Text/Pandoc/Writers/Roff.hs b/src/Text/Pandoc/Writers/Roff.hs
index d5602ebfb..7214e32f0 100644
--- a/src/Text/Pandoc/Writers/Roff.hs
+++ b/src/Text/Pandoc/Writers/Roff.hs
@@ -112,9 +112,11 @@ fontChange = do
                        fromMaybe False (Map.lookup 'B' features)] ++
                 ['I' | fromMaybe False $ Map.lookup 'I' features]
   return $
-    if null filling
-       then text "\\f[R]"
-       else text $ "\\f[" ++ filling ++ "]"
+    case filling of
+      [] -> text "\\f[R]"
+      -- see #9020. C is not a font, use CR.
+      ['C'] -> text "\\f[CR]"
+      _ -> text $ "\\f[" ++ filling ++ "]"
 
 withFontFeature :: (HasChars a, IsString a, PandocMonad m)
                 => Char -> MS m (Doc a) -> MS m (Doc a)