RST writer: add empty comments when needed...

to avoid including a blocquote in the indented content
of a preceding block.

Closes #3675.

src/Text/Pandoc/Writers/RST.hs

@@ -57,6 +57,7 @@ data WriterState =
               , stHasRawTeX   :: Bool
               , stOptions     :: WriterOptions
               , stTopLevel    :: Bool
+              , stLastNested  :: Bool
               }
 
 type RST = StateT WriterState
@@ -67,7 +68,7 @@ writeRST opts document = do
   let st = WriterState { stNotes = [], stLinks = [],
                          stImages = [], stHasMath = False,
                          stHasRawTeX = False, stOptions = opts,
-                         stTopLevel = True}
+                         stTopLevel = True, stLastNested = False}
   evalStateT (pandocToRST document) st
 
 -- | Return RST representation of document.
@@ -343,11 +344,32 @@ blockListToRST' :: PandocMonad m
                 -> RST m Doc
 blockListToRST' topLevel blocks = do
   tl <- gets stTopLevel
-  modify (\s->s{stTopLevel=topLevel})
-  res <- vcat `fmap` mapM blockToRST blocks
+  modify (\s->s{stTopLevel=topLevel, stLastNested=False})
+  res <- vcat `fmap` mapM blockToRST' blocks
   modify (\s->s{stTopLevel=tl})
   return res
 
+blockToRST' :: PandocMonad m => Block -> RST m Doc
+blockToRST' (x@BlockQuote{}) = do
+  lastNested <- gets stLastNested
+  res <- blockToRST x
+  modify (\s -> s{stLastNested = True})
+  return $ if lastNested
+              then ".." $+$ res
+              else res
+blockToRST' x = do
+  modify (\s -> s{stLastNested =
+    case x of
+         Para [Image _ _ (_,'f':'i':'g':':':_)] -> True
+         Para{} -> False
+         Plain{} -> False
+         Header{} -> False
+         LineBlock{} -> False
+         HorizontalRule -> False
+         _ -> True
+    })
+  blockToRST x
+
 blockListToRST :: PandocMonad m
                => [Block]       -- ^ List of block elements
                -> RST m Doc

test/command/3675.md

@@ -0,0 +1,15 @@
+````
+% pandoc -t rst
+```python
+print("hello")
+```
+> block quote
+^D
+.. code:: python
+
+    print("hello")
+
+..
+
+    block quote
+````

test/writer.rst

@@ -75,6 +75,8 @@ E-mail style:
 
     This is a block quote. It is pretty short.
 
+..
+
     Code in a block quote:
 
     ::
@@ -92,6 +94,8 @@ E-mail style:
 
         nested
 
+    ..
+
         nested
 
 This should not be a block quote: 2 > 1.
@@ -342,6 +346,8 @@ Multiple blocks with italics:
 
         { orange code block }
 
+    ..
+
         orange block quote
 
 Multiple definitions, tight: