Markdown writer: don't create autolinks when this loses information.

Previously we sometimes lost attributes when rendering links as autolinks.

Closes #7692.

src/Text/Pandoc/Writers/Markdown/Inline.hs

@@ -531,7 +531,7 @@ inlineToMarkdown opts (Cite (c:cs) lst)
            return $ pdoc <+> r
         modekey SuppressAuthor = "-"
         modekey _              = ""
-inlineToMarkdown opts lnk@(Link attr txt (src, tit)) = do
+inlineToMarkdown opts lnk@(Link attr@(ident,classes,kvs) txt (src, tit)) = do
   variant <- asks envVariant
   linktext <- inlineListToMarkdown opts txt
   let linktitle = if T.null tit
@@ -539,6 +539,9 @@ inlineToMarkdown opts lnk@(Link attr txt (src, tit)) = do
                      else literal $ " \"" <> tit <> "\""
   let srcSuffix = fromMaybe src (T.stripPrefix "mailto:" src)
   let useAuto = isURI src &&
+                T.null ident &&
+                null kvs &&
+               (null classes || classes == ["uri"] || classes == ["email"]) &&
                 case txt of
                       [Str s] | escapeURI s == srcSuffix -> True
                       _       -> False

test/command/7692.md

@@ -0,0 +1,13 @@
+```
+% pandoc -t markdown
+[https://example.com](https://example.com){.clz}
+^D
+[https://example.com](https://example.com){.clz}
+```
+
+```
+% pandoc -f markdown -t html | pandoc -f html -t markdown
+<http://example.com>
+^D
+<http://example.com>
+```