--- a/check_whitespace.py	Wed Jun 12 09:05:17 2019 +0200
+++ b/check_whitespace.py	Tue Apr 14 19:24:46 2020 +0200
@@ -39,27 +39,27 @@
     linenum = 0
     header = False
     filename = ''
-    fnre = re.compile(r'(?:---|\+\+\+) (?P<filename>[^\t\r\n]+)')
-    lnre = re.compile(r'@@ -\d+,\d+ \+(?P<lineno>\d+),')
-    wsre = re.compile(r'\+.*[ \t]$')
-    tbre = re.compile(r'\+.*\t')
-    resre = re.compile(r'\+(<<<<<<<|>>>>>>>|======= end)')
+    fnre = re.compile(br'(?:---|\+\+\+) (?P<filename>[^\t\r\n]+)')
+    lnre = re.compile(br'@@ -\d+,\d+ \+(?P<lineno>\d+),')
+    wsre = re.compile(br'\+.*[ \t]$')
+    tbre = re.compile(br'\+.*\t')
+    resre = re.compile(br'\+(<<<<<<<|>>>>>>>|======= end)')
     adding = False
     islink = False              # symlinks can have no newline at end
 
     for chunk in difflines:
-        for line in chunk.split('\n'):
+        for line in chunk.split(b'\n'):
             if header:
-                if line.startswith('new file mode'):
-                    islink = '120000' in line
+                if line.startswith(b'new file mode'):
+                    islink = b'120000' in line
                 # remember the name of the file that this diff affects
                 m = fnre.match(line)
-                if m is not None and m.group('filename') != '/dev/null':
-                    filename = m.group('filename').split('/', 1)[-1]
-                if line.startswith('+++ '):
+                if m is not None and m.group('filename') != b'/dev/null':
+                    filename = m.group('filename').split(b'/', 1)[-1]
+                if line.startswith(b'+++ '):
                     header = False
                 continue
-            if line.startswith('diff '):
+            if line.startswith(b'diff '):
                 header = True
                 adding = False
                 islink = False
@@ -71,44 +71,44 @@
                 continue
             if header or not filename:
                 continue
-            if line[:1] == '+':
+            if line[:1] == b'+':
                 adding = True
-            elif line[:1] in (' ', '-'):
+            elif line[:1] in (b' ', b'-'):
                 adding = False
             elif adding \
                  and not islink \
-                 and line.startswith(r'\ No newline at end of file') \
-                 and not filename.endswith('vertoo.data') \
+                 and line.startswith(br'\ No newline at end of file') \
+                 and not filename.endswith(b'vertoo.data') \
                  and not os.path.splitext(filename)[1] in binary_suffixes:
                 adding = False
-                yield filename, linenum, 'no newline at end of file'
+                yield filename, linenum, b'no newline at end of file'
             # hunk body - check for an added line with bad whitespace
-            if filename[-3:] == '.py' or filename[-5:] == '.py.in':
+            if filename[-3:] == b'.py' or filename[-5:] == b'.py.in':
                 m = tbre.match(line)
                 if m is not None:
-                    yield filename, linenum, 'TABs'
+                    yield filename, linenum, b'TABs'
             # trailing whitespace, for now only in Python source
             m = wsre.match(line)
             if m is not None:
-                if filename[-3:] == '.py' or filename[-5:] == '.py.in':
-                    yield filename, linenum, 'trailing whitespace'
+                if filename[-3:] == b'.py' or filename[-5:] == b'.py.in':
+                    yield filename, linenum, b'trailing whitespace'
             # conflict markers
             m = resre.match(line)
             if m is not None:
-                yield filename, linenum, 'conflict marker'
-            if line and line[0] in ' +':
+                yield filename, linenum, b'conflict marker'
+            if line and line[0] in b' +':
                 linenum += 1
 
 def hook(ui, repo, hooktype, node=None, source=None, **kwargs):
     import os, sys, subprocess
-    if hooktype not in ['pretxnchangegroup', 'pretxncommit']:
-        ui.write('Hook should be pretxncommit/pretxnchangegroup not "%s".' % hooktype)
+    if hooktype not in [b'pretxnchangegroup', b'pretxncommit']:
+        ui.write(b'Hook should be pretxncommit/pretxnchangegroup not "%s".' % hooktype)
         return 1
     added = False
     branches = {}
-    for rev in xrange(repo[node].rev(), len(repo)):
+    for rev in range(repo[node].rev(), len(repo)):
         branch = repo[rev].branch()
-        if not branches.has_key(branch):
+        if branch not in branches:
             # first time we see this branch, remember parents to diff against
             branches[branch] = repo[rev].parents()
         desc = 0