Markdown reader: Allow linebreaks in URLs (treat as spaces).

Also, a string of consecutive spaces or tabs is now parsed
as a single space. If you have multiple spaces in your URL,
use %20%20.

src/Text/Pandoc/Readers/Markdown.hs

@@ -202,9 +202,17 @@ referenceKey = try $ do
   lab <- reference
   char ':'
   skipSpaces >> optional newline >> skipSpaces >> notFollowedBy (char '[')
-  let sourceURL excludes = many $
-        optional (char '\\') >> (noneOf (' ':excludes) <|> (notFollowedBy' referenceTitle >> char ' '))
-  src <- try (char '<' >> sourceURL ">\t\n" >>~ char '>') <|> sourceURL "\t\n"
+  let nl = char '\n' >> notFollowedBy blankline >> return ' '
+  let sourceURL = liftM unwords $ many $ try $ do
+                    notFollowedBy' referenceTitle
+                    skipMany (oneOf " \t")
+                    optional nl
+                    notFollowedBy' reference
+                    skipMany (oneOf " \t")
+                    many1 (noneOf " \t\n")
+  let betweenAngles = try $ char '<' >>
+                            manyTill (noneOf ">\n" <|> nl) (char '>')
+  src <- try betweenAngles <|> sourceURL
   tit <- option "" referenceTitle
   blanklines
   endPos <- getPosition
@@ -1116,9 +1124,16 @@ source =
 source' :: GenParser Char st (String, [Char])
 source' = do
   skipSpaces
-  let sourceURL excludes = many $
-        optional (char '\\') >> (noneOf (' ':excludes) <|> (notFollowedBy' linkTitle >> char ' '))
-  src <- try (char '<' >> sourceURL ">\t\n" >>~ char '>') <|> sourceURL "\t\n"
+  let nl = char '\n' >>~ notFollowedBy blankline
+  let sourceURL = liftM unwords $ many $ try $ do
+                    notFollowedBy' linkTitle
+                    skipMany (oneOf " \t")
+                    optional nl
+                    skipMany (oneOf " \t")
+                    many1 (noneOf " \t\n")
+  let betweenAngles = try $ char '<' >>
+                            manyTill (noneOf ">\n" <|> nl) (char '>')
+  src <- try betweenAngles <|> sourceURL
   tit <- option "" linkTitle
   skipSpaces
   eof

tests/markdown-reader-more.native

@@ -6,7 +6,7 @@ Pandoc (Meta {docTitle = [Str "Title",Space,Str "spanning",Space,Str "multiple",
 , Para [TeX "\\placeformula",Space,TeX "\\startformula\n   L_{1} = L_{2}\n   \\stopformula"]
 , Para [TeX "\\start[a2]\n\\start[a2]\n\\stop[a2]\n\\stop[a2]"]
 , Header 2 [Str "URLs",Space,Str "with",Space,Str "spaces"]
-, Para [Link [Str "foo"] ("/bar%20and%20baz",""),Space,Link [Str "foo"] ("/bar%20and%20baz",""),Space,Link [Str "foo"] ("/bar%20%20and%20%20baz",""),Space,Link [Str "foo"] ("bar%20baz","title")]
+, Para [Link [Str "foo"] ("/bar%20and%20baz",""),Space,Link [Str "foo"] ("/bar%20and%20baz",""),Space,Link [Str "foo"] ("/bar%20and%20baz",""),Space,Link [Str "foo"] ("bar%20baz","title")]
 , Para [Link [Str "baz"] ("/foo%20foo",""),Space,Link [Str "bam"] ("/foo%20fee",""),Space,Link [Str "bork"] ("/foo/zee%20zob","title")]
 , Header 2 [Str "Horizontal",Space,Str "rules",Space,Str "with",Space,Str "spaces",Space,Str "at",Space,Str "end"]
 , HorizontalRule

tests/markdown-reader-more.txt

@@ -31,7 +31,8 @@
 ## URLs with spaces
 
 [foo](/bar and baz)
-[foo](/bar and baz )
+[foo](/bar
+ and baz )
 [foo]( /bar  and  baz  )
 [foo](bar baz  "title" )