Fix 'Ext_lists_without_preceding_blankline' bug.

  * Fixes #1636.
  * Adds a test.

1 files changed, 9 insertions, 2 deletions

diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 02a787670..239fb4184 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -117,6 +117,12 @@ isBlank _    = False
 -- auxiliary functions
 --
 
+-- | Succeeds when we're in list context.
+inList :: MarkdownParser ()
+inList = do
+  ctx <- stateParserContext <$> getState
+  guard (ctx == ListItemState)
+
 isNull :: F Inlines -> Bool
 isNull ils = B.isNull $ runF ils def
 
@@ -926,6 +932,8 @@ para = try $ do
               <|> (guardEnabled Ext_backtick_code_blocks >> () <$ lookAhead codeBlockFenced)
               <|> (guardDisabled Ext_blank_before_header >> () <$ lookAhead header)
               <|> (guardEnabled Ext_lists_without_preceding_blankline >>
+                       -- Avoid creating a paragraph in a nested list.
+                       notFollowedBy' inList >>
                        () <$ lookAhead listStart)
               <|> do guardEnabled Ext_native_divs
                      inHtmlBlock <- stateInHtmlBlock <$> getState
@@ -1610,8 +1618,7 @@ endline = try $ do
   newline
   notFollowedBy blankline
   -- parse potential list-starts differently if in a list:
-  st <- getState
-  when (stateParserContext st == ListItemState) $ notFollowedBy listStart
+  notFollowedBy (inList >> listStart)
   guardDisabled Ext_lists_without_preceding_blankline <|> notFollowedBy listStart
   guardEnabled Ext_blank_before_blockquote <|> notFollowedBy emailBlockQuoteStart
   guardEnabled Ext_blank_before_header <|> notFollowedBy (char '#') -- atx header