Markdown writer: Fix ordered list bug.

Previously ordered lists starting with a code block did not
round trip. Pandoc uses an indented code block, and according
to commonmark rules only one space is gobbled after the list
marker; however, pandoc added two.  This has now been fixed.
An incidental change fixes an oddity in markua list indentation.

Closes #11762.

src/Text/Pandoc/Writers/Markdown.hs

@@ -724,13 +724,8 @@ blockToMarkdown' opts (OrderedList (start,sty,delim) items) = do
              | otherwise = DefaultDelim
   let attribs = (start', sty', delim')
   let markers  = orderedListMarkers attribs
-  let markers' = case variant of
-                        Markua -> markers
-                        _ -> map (\m -> if T.length m < 3
-                                   then m <> T.replicate (3 - T.length m) " "
-                                   else m) markers
   contents <- inList $
-              zipWithM (orderedListItemToMarkdown opts) markers' items
+              zipWithM (orderedListItemToMarkdown opts) markers items
   return $ (if isTightList items then vcat else vsep) contents <> blankline
 blockToMarkdown' opts (DefinitionList items) = do
   contents <- inList $ mapM (definitionListItemToMarkdown opts) items
@@ -843,15 +838,18 @@ orderedListItemToMarkdown opts marker bs = do
   let exts = writerExtensions opts
   contents <- blockListToMarkdown opts $ taskListItemToAscii exts bs
   variant <- asks envVariant
+  let beginsWithCodeBlock = case bs of
+                             CodeBlock{} : _ -> True
+                             _ -> False
   let sps = case writerTabStop opts - T.length marker of
-                   n | n > 0 -> literal $ T.replicate n " "
-                   _ -> literal " "
+                   _ | beginsWithCodeBlock -> 1 -- see #11762
+                   _ | variant == Markua -> 1
+                   n | n > 0 -> n
+                   _ -> 1
   let ind = if isEnabled Ext_four_space_rule opts
                then writerTabStop opts
-               else max (writerTabStop opts) (T.length marker + 1)
-  let start = case variant of
-              Markua -> literal marker <> " "
-              _      -> literal marker <> sps
+               else T.length marker + sps
+  let start = literal marker <> literal (T.replicate sps " ")
   -- remove trailing blank line if item ends with a tight list
   let contents' = if itemEndsWithTightList bs
                      then chomp contents <> cr

test/command/11762.md

@@ -0,0 +1,12 @@
+```
+% pandoc -f native -t commonmark | pandoc -f commonmark -t native
+[ OrderedList
+    ( 1 , Decimal , Period )
+    [ [ CodeBlock ( "" , [] , [] ) "hi" ] ]
+]
+^D
+[ OrderedList
+    ( 1 , Decimal , Period )
+    [ [ CodeBlock ( "" , [] , [] ) "hi" ] ]
+]
+```

test/writer.markua

@@ -192,7 +192,7 @@ Multiple paragraphs:
 
 1. Item 1, graf one.
 
-    Item 1. graf two. The quick brown fox jumped over the lazy dog’s back.
+   Item 1. graf two. The quick brown fox jumped over the lazy dog’s back.
 
 2. Item 2.
 
@@ -209,9 +209,9 @@ Here’s another:
 
 1. First
 2. Second:
-    * Fee
-    * Fie
-    * Foe
+   * Fee
+   * Fie
+   * Foe
 3. Third
 
 Same thing but with paragraphs:
@@ -220,9 +220,9 @@ Same thing but with paragraphs:
 
 2. Second:
 
-    * Fee
-    * Fie
-    * Foe
+   * Fee
+   * Fie
+   * Foe
 
 3. Third
 
@@ -244,25 +244,25 @@ Same thing but with paragraphs:
 
 3) and now 3
 
-    with a continuation
+   with a continuation
 
-    i. sublist with roman numerals starting with i.
-    ii. more items
-        A) a subsublist
-        B) a subsublist
+   i. sublist with roman numerals starting with i.
+   ii. more items
+       A) a subsublist
+       B) a subsublist
 
 Nesting:
 
 D. Upper Alpha
-    I. Upper Roman.
-        1) Decimal start with 1
-            a) Lower alpha with paren
+   I. Upper Roman.
+      1) Decimal start with 1
+         a) Lower alpha with paren
 
 Autonumbering:
 
 1. Autonumber.
 2. More.
-    1. Nested.
+   1. Nested.
 
 Should not be a list item: