Changed Markdown writer so that it does not use the single-bracket

style of implicit reference link.  It now uses [this style][],
not [this style].  Reason:  only newer, beta versions of Markdown
allow the single-bracket style.


git-svn-id: https://pandoc.googlecode.com/svn/trunk@419 788f1e2b-df1e-0410-8736-df70ead52e1b

src/Text/Pandoc/Writers/Markdown.hs

@@ -176,7 +176,7 @@ inlineToMarkdown (Link txt (Src src tit)) =
 inlineToMarkdown (Link txt (Ref ref)) = 
   let first = char '[' <> inlineListToMarkdown txt <> char ']'
       second = if (txt == ref) 
-                 then empty
+                 then text "[]"
                  else char '[' <> inlineListToMarkdown ref <> char ']' in
       first <> second
 inlineToMarkdown (Image alternate (Src source tit)) = 

tests/writer.markdown

@@ -531,13 +531,13 @@ Foo [bar][a].
 
 With [embedded [brackets]][b].
 
-[b] by itself should be a link.
+[b][] by itself should be a link.
 
-Indented [once].
+Indented [once][].
 
-Indented [twice].
+Indented [twice][].
 
-Indented [thrice].
+Indented [thrice][].
 
 This should [not][] be a link.
 
@@ -550,7 +550,7 @@ This should [not][] be a link.
 
   [b]: /url/
 
-Foo [bar].
+Foo [bar][].
 
 Foo [biz](/url/ "Title with "quote" inside").
 
@@ -595,7 +595,7 @@ Auto-links should not occur here: `<http://example.com/>`
 
 From "Voyage dans la Lune" by Georges Melies (1902):
 
-![lalune]
+![lalune][]
 
 
   [lalune]: lalune.jpg "Voyage dans la Lune"