Update list of empty HTML tags

Use Python standard library's HTML_EMPTY which already contains the new tags. Fixes #1353.

Author: nicbou

docs/changelog.md

@@ -25,6 +25,7 @@ links to the header, placing them after all other header content.
 * Add support for cPython version 3.12 (and PyPy 3.10) and drop support for
   Python version 3.7 (#1357).
 * Refactor changelog to use the format defined at <https://keepachangelog.com/>.
+* Updated the list of empty HTML tags (#1353).
 
 ## [3.4.4] -- 2023-07-25
 

markdown/serializers.py

@@ -34,22 +34,14 @@
 # OF THIS SOFTWARE.
 # --------------------------------------------------------------------
 
-
 from xml.etree.ElementTree import ProcessingInstruction
-from xml.etree.ElementTree import Comment, ElementTree, QName
+from xml.etree.ElementTree import Comment, ElementTree, QName, HTML_EMPTY
 import re
 
 __all__ = ['to_html_string', 'to_xhtml_string']
 
-HTML_EMPTY = ("area", "base", "basefont", "br", "col", "frame", "hr",
-              "img", "input", "isindex", "link", "meta", "param")
 RE_AMP = re.compile(r'&(?!(?:\#[0-9]+|\#x[0-9a-f]+|[0-9a-z]+);)', re.I)
 
-try:
-    HTML_EMPTY = set(HTML_EMPTY)
-except NameError:  # pragma: no cover
-    pass
-
 
 def _raise_serialization_error(text):  # pragma: no cover
     raise TypeError(