Implemented Ext_markdown_attribute.

This adds markdown=1 to block tags.

3 files changed, 17 insertions, 1 deletions

diff --git a/README b/README
index 4b27f3dde..29f6f2ff1 100644
--- a/README
+++ b/README
@@ -2207,6 +2207,12 @@ Causes anything between `\\(` and `\\)` to be interpreted as inline
 TeX math, and anything between `\\[` and `\\]` to be interpreted
 as display TeX math.
 
+**Extension: `markdown_attribute`**\
+Causes the attribute `markdown=1` to be added to all block-level
+HTML tags that might contain markdown.  In pandoc, material inside
+block-level tags is interpreted a markdown by default, but in some
+other implementations, the `markdown=1` tag is needed.
+
 Producing slide shows with Pandoc
 =================================
 
diff --git a/src/Text/Pandoc/Options.hs b/src/Text/Pandoc/Options.hs
index f7f07a939..6d235e7a8 100644
--- a/src/Text/Pandoc/Options.hs
+++ b/src/Text/Pandoc/Options.hs
@@ -64,6 +64,7 @@ data Extension = Ext_footnotes
                | Ext_delimited_code_blocks
                | Ext_inline_code_attributes
                | Ext_markdown_in_html_blocks
+               | Ext_markdown_attribute
                | Ext_escaped_line_breaks
                | Ext_autolink_code_spans
                | Ext_fancy_lists
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 8a1299de6..fbcdeeb14 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -736,10 +736,19 @@ rawTeXBlock = do
   spaces
   return $ return result
 
+addMarkdownAttribute :: (Tag String, String) -> Parser [Char] ParserState String
+addMarkdownAttribute (t,s) = do
+  (guardDisabled Ext_markdown_attribute >> return s)
+ <|>  case t of
+       TagOpen x attrs
+         | "markdown" `elem` map fst attrs -> return s
+         | otherwise -> return $ renderTags [TagOpen x (("markdown","1"):attrs)]
+       _ -> return s
+
 rawHtmlBlocks :: Parser [Char] ParserState String
 rawHtmlBlocks = do
   htmlBlocks <- many1 $ do blk <- rawVerbatimBlock <|>
-                                   liftM snd (htmlTag isBlockTag)
+                                   (htmlTag isBlockTag >>= addMarkdownAttribute)
                            sps <- do sp1 <- many spaceChar
                                      sp2 <- option "" (blankline >> return "\n")
                                      sp3 <- many spaceChar