Ms writer: font improvements.

* Use `\f[R]` rather than `\f[]` to reset.  The latter
  returns to the previous font, which gives unintended
  results in some cases.
* Use `\f[BI]` and `\f[CB]` in headers, instead of `\f[I]` and `\f[C]`,
  since the header font is automatically bold.
* Use `\f[CB]` rather than `\f[BC]` for monospace bold.

Closes #4552.

2 files changed, 39 insertions, 28 deletions

diff --git a/src/Text/Pandoc/Writers/Ms.hs b/src/Text/Pandoc/Writers/Ms.hs
index 4731d4a9f..16a66c85b 100644
--- a/src/Text/Pandoc/Writers/Ms.hs
+++ b/src/Text/Pandoc/Writers/Ms.hs
@@ -40,7 +40,7 @@ module Text.Pandoc.Writers.Ms ( writeMs ) where
 import Prelude
 import Control.Monad.State.Strict
 import Data.Char (isLower, isUpper, toUpper, ord)
-import Data.List (intercalate, intersperse, sort)
+import Data.List (intercalate, intersperse)
 import qualified Data.Map as Map
 import Data.Maybe (catMaybes, fromMaybe)
 import Data.Text (Text)
@@ -68,6 +68,7 @@ data WriterState = WriterState { stHasInlineMath :: Bool
                                , stNotes         :: [Note]
                                , stSmallCaps     :: Bool
                                , stHighlighting  :: Bool
+                               , stInHeader      :: Bool
                                , stFontFeatures  :: Map.Map Char Bool
                                }
 
@@ -77,6 +78,7 @@ defaultWriterState = WriterState{ stHasInlineMath = False
                                 , stNotes         = []
                                 , stSmallCaps     = False
                                 , stHighlighting  = False
+                                , stInHeader      = False
                                 , stFontFeatures  = Map.fromList [
                                                        ('I',False)
                                                      , ('B',False)
@@ -264,7 +266,9 @@ blockToMs _ HorizontalRule = do
   return $ text ".HLINE"
 blockToMs opts (Header level (ident,classes,_) inlines) = do
   setFirstPara
+  modify $ \st -> st{ stInHeader = True }
   contents <- inlineListToMs' opts $ map breakToSpace inlines
+  modify $ \st -> st{ stInHeader = False }
   let (heading, secnum) = if writerNumberSections opts &&
                               "unnumbered" `notElem` classes
                              then (".NH", "\\*[SN]")
@@ -559,8 +563,15 @@ handleNote opts bs = do
 fontChange :: PandocMonad m => MS m Doc
 fontChange = do
   features <- gets stFontFeatures
-  let filling = sort [c | (c,True) <- Map.toList features]
-  return $ text $ "\\f[" ++ filling ++ "]"
+  inHeader <- gets stInHeader
+  let filling = ['C' | fromMaybe False $ Map.lookup 'C' features] ++
+                ['B' | inHeader ||
+                       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 ++ "]"
 
 withFontFeature :: PandocMonad m => Char -> MS m Doc -> MS m Doc
 withFontFeature c action = do
diff --git a/test/writer.ms b/test/writer.ms
index a95b5fe33..33dec71d3 100644
--- a/test/writer.ms
+++ b/test/writer.ms
@@ -86,7 +86,7 @@ Level 2 with an \c
 .pdfhref O 2 "Level 2 with an embedded link"
 .pdfhref M "level-2-with-an-embedded-link"
 .SH 3
-Level 3 with \f[I]emphasis\f[]
+Level 3 with \f[BI]emphasis\f[B]
 .pdfhref O 3 "Level 3 with emphasis"
 .pdfhref M "level-3-with-emphasis"
 .SH 4
@@ -102,7 +102,7 @@ Level 1
 .pdfhref O 1 "Level 1"
 .pdfhref M "level-1"
 .SH 2
-Level 2 with \f[I]emphasis\f[]
+Level 2 with \f[BI]emphasis\f[B]
 .pdfhref O 2 "Level 2 with emphasis"
 .pdfhref M "level-2-with-emphasis"
 .SH 3
@@ -481,13 +481,13 @@ yellow fruit
 .RE
 .LP
 Multiple blocks with italics:
-.IP "\f[I]apple\f[]"
+.IP "\f[I]apple\f[R]"
 red fruit
 .RS
 .PP
 contains seeds, crisp, pleasant to taste
 .RE
-.IP "\f[I]orange\f[]"
+.IP "\f[I]orange\f[R]"
 orange fruit
 .RS
 .IP
@@ -564,8 +564,8 @@ foo
 bar
 .LP
 Interpreted markdown in a table:
-This is \f[I]emphasized\f[]
-And this is \f[B]strong\f[]
+This is \f[I]emphasized\f[R]
+And this is \f[B]strong\f[R]
 .PP
 Here’s a simple block:
 .LP
@@ -621,29 +621,29 @@ Inline Markup
 .pdfhref O 1 "Inline Markup"
 .pdfhref M "inline-markup"
 .LP
-This is \f[I]emphasized\f[], and so \f[I]is this\f[].
+This is \f[I]emphasized\f[R], and so \f[I]is this\f[R].
 .PP
-This is \f[B]strong\f[], and so \f[B]is this\f[].
+This is \f[B]strong\f[R], and so \f[B]is this\f[R].
 .PP
 An \f[I]\c
 .pdfhref W -D "/url" -A "\c" \
  -- "emphasized link"
-\&\f[].
+\&\f[R].
 .PP
-\f[B]\f[BI]This is strong and em.\f[B]\f[]
+\f[B]\f[BI]This is strong and em.\f[B]\f[R]
 .PP
-So is \f[B]\f[BI]this\f[B]\f[] word.
+So is \f[B]\f[BI]this\f[B]\f[R] word.
 .PP
-\f[B]\f[BI]This is strong and em.\f[B]\f[]
+\f[B]\f[BI]This is strong and em.\f[B]\f[R]
 .PP
-So is \f[B]\f[BI]this\f[B]\f[] word.
+So is \f[B]\f[BI]this\f[B]\f[R] word.
 .PP
-This is code: \f[C]>\f[], \f[C]$\f[], \f[C]\\\f[], \f[C]\\$\f[],
-\f[C]<html>\f[].
+This is code: \f[C]>\f[R], \f[C]$\f[R], \f[C]\\\f[R], \f[C]\\$\f[R],
+\f[C]<html>\f[R].
 .PP
-\m[strikecolor]This is \f[I]strikeout\f[].\m[]
+\m[strikecolor]This is \f[I]strikeout\f[R].\m[]
 .PP
-Superscripts: a\*{bc\*}d a\*{\f[I]hello\f[]\*} a\*{hello\~there\*}.
+Superscripts: a\*{bc\*}d a\*{\f[I]hello\f[R]\*} a\*{hello\~there\*}.
 .PP
 Subscripts: H\*<2\*>O, H\*<23\*>O, H\*<many\~of\~them\*>O.
 .PP
@@ -665,7 +665,7 @@ So is `pine.'
 .PP
 `He said, \[lq]I want to go.\[rq]' Were you alive in the 70’s?
 .PP
-Here is some quoted `\f[C]code\f[]' and a \[lq]\c
+Here is some quoted `\f[C]code\f[R]' and a \[lq]\c
 .pdfhref W -D "http://example.com/?foo=1&bar=2" -A "\c" \
  -- "quoted link"
 \&\[rq].
@@ -701,15 +701,15 @@ Here’s one that has a line break in it: @alpha + omega times x sup 2@.
 .LP
 These shouldn’t be math:
 .IP \[bu] 3
-To get the famous equation, write \f[C]$e\ =\ mc\[ha]2$\f[].
+To get the famous equation, write \f[C]$e\ =\ mc\[ha]2$\f[R].
 .IP \[bu] 3
-$22,000 is a \f[I]lot\f[] of money.
+$22,000 is a \f[I]lot\f[R] of money.
 So is $34,000.
 (It worked if \[lq]lot\[rq] is emphasized.)
 .IP \[bu] 3
 Shoes ($20) and socks ($5).
 .IP \[bu] 3
-Escaped \f[C]$\f[]: $73 \f[I]this should be emphasized\f[] 23$.
+Escaped \f[C]$\f[R]: $73 \f[I]this should be emphasized\f[R] 23$.
 .LP
 Here’s a LaTeX table:
 .HLINE
@@ -932,7 +932,7 @@ Blockquoted: \c
 \&
 .RE
 .LP
-Auto-links should not occur here: \f[C]<http://example.com/>\f[]
+Auto-links should not occur here: \f[C]<http://example.com/>\f[R]
 .IP
 .nf
 \f[C]
@@ -979,14 +979,14 @@ with list items).
 If you want, you can indent every line, but you can also be lazy and just
 indent the first line of each block.
 .FE
-This should \f[I]not\f[] be a footnote reference, because it contains a
+This should \f[I]not\f[R] be a footnote reference, because it contains a
 space.[\[ha]my note] Here is an inline note.\**
 .FS
-This is \f[I]easier\f[] to type.
+This is \f[I]easier\f[R] to type.
 Inline notes may contain \c
 .pdfhref W -D "http://google.com" -A "\c" \
  -- "links"
-\& and \f[C]]\f[] verbatim characters, as well as [bracketed text].
+\& and \f[C]]\f[R] verbatim characters, as well as [bracketed text].
 .FE
 .RS
 .LP