hgweb: skip body creation of HEAD for most requests The body is thrown away anyway, so this just wastes a lot of CPU time. In the case of /archive/, this skips manifest processing and the actual file archiving, resulting in a huge difference. The most tricky part here is skipping the Content-Length creation as it would indicate the output size for the corresponding GET request.

--- a/mercurial/hgweb/webcommands.py	Wed Jan 04 16:02:22 2023 +0100
+++ b/mercurial/hgweb/webcommands.py	Fri Dec 16 17:46:20 2022 +0100
@@ -1299,6 +1299,9 @@
             b'sendresponse() should not emit data if writing later'
         )
 
+    if web.req.method == b'HEAD':
+        return []
+
     bodyfh = web.res.getbodyfile()
 
     archival.archive(