--- a/check_whitespace.py	Tue Apr 14 19:24:46 2020 +0200
+++ b/check_whitespace.py	Thu Sep 03 18:17:08 2020 +0200
@@ -19,21 +19,21 @@
 import re
 import os
 
-binary_suffixes = (
-    '.bam',
-    '.bmp',
-    '.bz2',
-    '.chm',
-    '.cpl',
-    '.dia',
-    '.dll',
-    '.gz',
-    '.ico',
-    '.pdf',
-    '.png',
-    '.rtf',
-    '.zip',
-)
+binary_suffixes = {
+    b'.bam',
+    b'.bmp',
+    b'.bz2',
+    b'.chm',
+    b'.cpl',
+    b'.dia',
+    b'.dll',
+    b'.gz',
+    b'.ico',
+    b'.pdf',
+    b'.png',
+    b'.rtf',
+    b'.zip',
+}
 
 def trailing_whitespace(difflines):
     linenum = 0
@@ -71,9 +71,9 @@
                 continue
             if header or not filename:
                 continue
-            if line[:1] == b'+':
+            if line.startswith(b'+'):
                 adding = True
-            elif line[:1] in (b' ', b'-'):
+            elif line.startswith(b' ') or line.startswith(b'-'):
                 adding = False
             elif adding \
                  and not islink \
@@ -118,15 +118,15 @@
             # no descendants for this revision, check diff with saved parents
             for p in branches[branch]:
                 for filename, linenum, msg in trailing_whitespace(repo[rev].diff(p)):
-                    ui.write('%s, line %d, branch %s: %s added\n' % (filename, linenum, branch, msg))
+                    ui.write(b'%s, line %d, branch %s: %s added\n' % (filename, linenum, branch, msg))
                     added = True
     if added:
         # save the commit message so we don't need to retype it
         if source != 'serve':
-            cmtsv = os.path.join('.hg','commit.save')
+            cmtsv = os.path.join(b'.hg',b'commit.save')
             subprocess.call(['hg', 'tip', '--template', '{desc}'],
                             stdout=open(cmtsv, 'w'))
-            ui.write('commit message saved to %s\n' % cmtsv)
+            ui.write(b'commit message saved to %s\n' % cmtsv)
         return 1
 
 if __name__ == '__main__':