RST reader: handle class attribute for for custom roles (#7700)

Previously the class attribute was ignored, and the name of the role used as the class.
Closes #7699.

1 files changed, 16 insertions, 8 deletions

diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index 8ee017342..88471eb0a 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -919,14 +919,22 @@ addNewRole roleText fields = do
         (baseRole, baseFmt, baseAttr) =
                getBaseRole (parentRole, Nothing, nullAttr) customRoles
         fmt = if parentRole == "raw" then lookup "format" fields else baseFmt
-        annotate :: [Text] -> [Text]
-        annotate = maybe id (:) $
-            if baseRole == "code"
-               then lookup "language" fields
-               else Nothing
-        attr = let (ident, classes, keyValues) = baseAttr
-        -- nub in case role name & language class are the same
-               in (ident, nub . (role :) . annotate $ classes, keyValues)
+
+        updateClasses :: [Text] -> [Text]
+        updateClasses oldClasses = let
+
+          codeLanguageClass = if baseRole == "code"
+            then maybeToList (lookup "language" fields)
+            else []
+
+          -- if no ":class:" field is given, the default is the role name
+          classFieldClasses = maybe [role] T.words (lookup "class" fields)
+
+          -- nub in case role name & language class are the same
+          in nub (classFieldClasses ++ codeLanguageClass ++ oldClasses)
+
+        attr = let (ident, baseClasses, keyValues) = baseAttr
+               in (ident, updateClasses baseClasses, keyValues)
 
     -- warn about syntax we ignore
     forM_ fields $ \(key, _) -> case key of