hgweb: always compute all entries and latestentry in changelog

Get the whole list of entries before rendering instead of using lazy evaluation.
This doesn't affect the performance for usual case when the entries are shown
anyway. When both entries and latestentry are used, this performs unnoticeably
faster, and for pages which use only latestentry (quite uncommon case) it
would be a bit slower.
This change will make it possible to get the first entry of the next page easily
without computing the list twice.

mercurial/hgweb/webcommands.py

@@ -259,12 +259,10 b' def changelog(web, req, tmpl, shortlog=F'
     else:
         ctx = web.repo['tip']
 
-    def changelist(latestonly):
+    def changelist():
         revs = []
         if pos != -1:
             revs = web.repo.changelog.revs(pos, 0)
-        if latestonly:
-            revs = (revs.next(),)
         curcount = 0
         for i in revs:
             ctx = web.repo[i]
@@ -309,10 +307,13 b' def changelog(web, req, tmpl, shortlog=F'
 
     changenav = webutil.revnav(web.repo).gen(pos, revcount, count)
 
+    entries = list(changelist())
+    latestentry = entries[:1]
+
     return tmpl(shortlog and 'shortlog' or 'changelog', changenav=changenav,
                 node=ctx.hex(), rev=pos, changesets=count,
-                entries=lambda **x: changelist(latestonly=False),
-                latestentry=lambda **x: changelist(latestonly=True),
+                entries=entries,
+                latestentry=latestentry,
                 archives=web.archivelist("tip"), revcount=revcount,
                 morevars=morevars, lessvars=lessvars, query=query)