From 92e0e424c059e568522b27ef438e651fe5b0a59b Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Sun, 19 Sep 2021 09:12:55 -0700
Subject: [PATCH] Markdown writer: use `underline` class rather than `ul` for
 underline.

This only affects output with bracketed_spans enabled.
The markdown reader parses spans with either `.ul` or `.underline` as
Underline elements, but we're moving towards preferring the latter.
---
 src/Text/Pandoc/Writers/Markdown/Inline.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Text/Pandoc/Writers/Markdown/Inline.hs b/src/Text/Pandoc/Writers/Markdown/Inline.hs
index f7a320db3..31c816e36 100644
--- a/src/Text/Pandoc/Writers/Markdown/Inline.hs
+++ b/src/Text/Pandoc/Writers/Markdown/Inline.hs
@@ -307,7 +307,7 @@ inlineToMarkdown opts (Underline lst) = do
   case variant of
     PlainText -> return contents
     _     | isEnabled Ext_bracketed_spans opts ->
-            return $ "[" <> contents <> "]" <> "{.ul}"
+            return $ "[" <> contents <> "]" <> "{.underline}"
           | isEnabled Ext_native_spans opts ->
             return $ tagWithAttrs "span" ("", ["underline"], [])
               <> contents