fix markdown quote

Author: xxchan

lib/syntax/block0.ml

@@ -28,15 +28,16 @@ struct
   let md_blockquote =
     char '>'
     *> lines_while
-         ( spaces *> optional (char '>') *> spaces *> line >>= fun line ->
-           if
-             not
-               (starts_with line "- " || starts_with line "# "
-              || starts_with line "id:: " || line = "-" || line = "#")
-           then
-             return line
-           else
-             fail "new block" )
+         (spaces *> char '>' *> spaces *> eol *> return ""
+         <|> ( spaces *> optional (char '>') *> spaces *> line >>= fun line ->
+               if
+                 not
+                   (starts_with line "- " || starts_with line "# "
+                  || starts_with line "id:: " || line = "-" || line = "#")
+               then
+                 return line
+               else
+                 fail "new block" ))
     <?> "markdown blockquote"
 
   let displayed_math =

test/test_markdown.ml

@@ -775,6 +775,29 @@ let block =
                      ; I.Break_Line
                      ]
                  ]) )
+        ; ( "multi lines (2)"
+          , `Quick
+          , check_aux ">foo\nbar"
+              (Quote
+                 [ paragraph
+                     [ I.Plain "foo"
+                     ; I.Break_Line
+                     ; I.Plain "bar"
+                     ; I.Break_Line
+                     ]
+                 ]) )
+        ; ( "multi lines (3)"
+          , `Quick
+          , check_aux ">foo\n>\n>bar"
+              (Quote
+                 [ paragraph
+                     [ I.Plain "foo"
+                     ; I.Break_Line
+                     ; I.Break_Line
+                     ; I.Plain "bar"
+                     ; I.Break_Line
+                     ]
+                 ]) )
         ] )
   ; ( "latex_env"
     , testcases