Markdown reader: distinguish autolinks in the AST.

With this change, autolinks are parsed as Links with
the `uri` class. (The same is true for bare links, if
the `autolink_bare_uris` extension is enabled.)  Email
autolinks are parsed as Links with the `email` class.
This allows the distinction to be represented in the
URI.

Formerly the `uri` class was added to autolinks by
the HTML writer, but it had to guess what was an autolink
and could not distinguish `[http://example.com](http://example.com)`
from `<http://example.com>`.  It also incorrectly recognized
`[pandoc](pandoc)` as an autolink.  Now the HTML writer
simply passes through the `uri` attribute if it is present,
but does not add anything.

The Textile writer has been modified so that the `uri`
class is not explicitly added for autolinks, even if it
is present.

Closes #4913.

3 files changed, 12 insertions, 13 deletions

diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 5f6788887..d1ea7a1a5 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE NoImplicitPrelude #-}
 {-# LANGUAGE RelaxedPolyRec      #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TupleSections #-}
 
 {-
 Copyright (C) 2006-2018 John MacFarlane <jgm@berkeley.edu>
@@ -1879,23 +1880,24 @@ bareURL :: PandocMonad m => MarkdownParser m (F Inlines)
 bareURL = try $ do
   guardEnabled Ext_autolink_bare_uris
   getState >>= guard . stateAllowLinks
-  (orig, src) <- uri <|> emailAddress
+  (cls, (orig, src)) <- (("uri",) <$> uri) <|> (("email",) <$> emailAddress)
   notFollowedBy $ try $ spaces >> htmlTag (~== TagClose "a")
-  return $ return $ B.link src "" (B.str orig)
+  return $ return $ B.linkWith ("",[cls],[]) src "" (B.str orig)
 
 autoLink :: PandocMonad m => MarkdownParser m (F Inlines)
 autoLink = try $ do
   getState >>= guard . stateAllowLinks
   char '<'
-  (orig, src) <- uri <|> emailAddress
+  (cls, (orig, src)) <- (("uri",) <$> uri) <|> (("email",) <$> emailAddress)
   -- in rare cases, something may remain after the uri parser
   -- is finished, because the uri parser tries to avoid parsing
   -- final punctuation.  for example:  in `<http://hi---there>`,
   -- the URI parser will stop before the dashes.
   extra <- fromEntities <$> manyTill nonspaceChar (char '>')
-  attr  <- option nullAttr $ try $
+  attr  <- option ("", [cls], []) $ try $
             guardEnabled Ext_link_attributes >> attributes
-  return $ return $ B.linkWith attr (src ++ escapeURI extra) "" (B.str $ orig ++ extra)
+  return $ return $ B.linkWith attr (src ++ escapeURI extra) ""
+                     (B.str $ orig ++ extra)
 
 image :: PandocMonad m => MarkdownParser m (F Inlines)
 image = try $ do
diff --git a/src/Text/Pandoc/Writers/HTML.hs b/src/Text/Pandoc/Writers/HTML.hs
index a0b622c83..851b48956 100644
--- a/src/Text/Pandoc/Writers/HTML.hs
+++ b/src/Text/Pandoc/Writers/HTML.hs
@@ -56,7 +56,7 @@ import Data.String (fromString)
 import Data.Text (Text)
 import qualified Data.Text.Lazy as TL
 import Network.HTTP (urlEncode)
-import Network.URI (URI (..), parseURIReference, unEscapeString)
+import Network.URI (URI (..), parseURIReference)
 import Numeric (showHex)
 import Text.Blaze.Internal (customLeaf, customParent, MarkupM(Empty))
 #if MIN_VERSION_blaze_markup(0,6,3)
@@ -1084,10 +1084,7 @@ inlineToHtml opts inline = do
                                              in  '#' : prefix ++ xs
                                    _ -> s
                         let link = H.a ! A.href (toValue s') $ linkText
-                        let attr = if txt == [Str (unEscapeString s)]
-                                      then (ident, "uri" : classes, kvs)
-                                      else (ident, classes, kvs)
-                        link' <- addAttrs opts attr link
+                        link' <- addAttrs opts (ident, classes, kvs) link
                         return $ if null tit
                                     then link'
                                     else link' ! A.title (toValue tit)
diff --git a/src/Text/Pandoc/Writers/Textile.hs b/src/Text/Pandoc/Writers/Textile.hs
index d1724f438..c7d96454a 100644
--- a/src/Text/Pandoc/Writers/Textile.hs
+++ b/src/Text/Pandoc/Writers/Textile.hs
@@ -463,15 +463,15 @@ inlineToTextile _ SoftBreak = return " "
 inlineToTextile _ Space = return " "
 
 inlineToTextile opts (Link (_, cls, _) txt (src, _)) = do
-  let classes = if null cls
-                   then ""
-                   else "(" ++ unwords cls ++ ")"
   label <- case txt of
                 [Code _ s]
                  | s == src -> return "$"
                 [Str s]
                  | s == src -> return "$"
                 _           -> inlineListToTextile opts txt
+  let classes = if null cls || cls == ["uri"] && label == "$"
+                   then ""
+                   else "(" ++ unwords cls ++ ")"
   return $ "\"" ++ classes ++ label ++ "\":" ++ src
 
 inlineToTextile opts (Image attr@(_, cls, _) alt (source, tit)) = do