diff -r 12450fbea288 -r 7431f5ab0d2a hgext/git/gitlog.py
--- a/hgext/git/gitlog.py	Fri Apr 30 02:11:58 2021 +0200
+++ b/hgext/git/gitlog.py	Mon May 03 18:55:19 2021 +0200
@@ -65,7 +65,8 @@
 
     def hasnode(self, n):
         t = self._db.execute(
-            'SELECT node FROM changelog WHERE node = ?', (n,)
+            'SELECT node FROM changelog WHERE node = ?',
+            (pycompat.sysstr(n),),
         ).fetchone()
         return t is not None
 
@@ -144,7 +145,7 @@
 
     def revs(self, start=0, stop=None):
         if stop is None:
-            stop = self.tip()
+            stop = self.tiprev()
         t = self._db.execute(
             'SELECT rev FROM changelog '
             'WHERE rev >= ? AND rev <= ? '
@@ -156,8 +157,11 @@
     def tiprev(self):
         t = self._db.execute(
             'SELECT rev FROM changelog ' 'ORDER BY REV DESC ' 'LIMIT 1'
-        )
-        return next(t)
+        ).fetchone()
+
+        if t is not None:
+            return t[0]
+        return -1
 
     def _partialmatch(self, id):
         if sha1nodeconstants.wdirhex.startswith(id):
@@ -165,7 +169,8 @@
         candidates = [
             bin(x[0])
             for x in self._db.execute(
-                'SELECT node FROM changelog WHERE node LIKE ?', (id + b'%',)
+                'SELECT node FROM changelog WHERE node LIKE ?',
+                (pycompat.sysstr(id + b'%'),),
             )
         ]
         if sha1nodeconstants.nullhex.startswith(id):
@@ -213,10 +218,11 @@
             n = self.node(nodeorrev)
         else:
             n = nodeorrev
+        extra = {b'branch': b'default'}
         # handle looking up nullid
         if n == sha1nodeconstants.nullid:
             return hgchangelog._changelogrevision(
-                extra={}, manifest=sha1nodeconstants.nullid
+                extra=extra, manifest=sha1nodeconstants.nullid
             )
         hn = gitutil.togitnode(n)
         # We've got a real commit!
@@ -233,7 +239,7 @@
             for r in self._db.execute(
                 'SELECT filename FROM changedfiles '
                 'WHERE node = ? and filenode = ?',
-                (hn, sha1nodeconstants.nullhex),
+                (hn, gitutil.nullgit),
             )
         ]
         c = self.gitrepo[hn]
@@ -247,7 +253,7 @@
             filesremoved=filesremoved,
             description=c.message.encode('utf8'),
             # TODO do we want to handle extra? how?
-            extra={b'branch': b'default'},
+            extra=extra,
         )
 
     def ancestors(self, revs, stoprev=0, inclusive=False):