--- a/mercurial/wireprototypes.py	Sun Oct 06 09:45:02 2019 -0400
+++ b/mercurial/wireprototypes.py	Sun Oct 06 09:48:39 2019 -0400
@@ -19,27 +19,27 @@
 from .utils import compression
 
 # Names of the SSH protocol implementations.
-SSHV1 = 'ssh-v1'
+SSHV1 = b'ssh-v1'
 # These are advertised over the wire. Increment the counters at the end
 # to reflect BC breakages.
-SSHV2 = 'exp-ssh-v2-0003'
-HTTP_WIREPROTO_V2 = 'exp-http-v2-0003'
+SSHV2 = b'exp-ssh-v2-0003'
+HTTP_WIREPROTO_V2 = b'exp-http-v2-0003'
 
-NARROWCAP = 'exp-narrow-1'
-ELLIPSESCAP1 = 'exp-ellipses-1'
-ELLIPSESCAP = 'exp-ellipses-2'
+NARROWCAP = b'exp-narrow-1'
+ELLIPSESCAP1 = b'exp-ellipses-1'
+ELLIPSESCAP = b'exp-ellipses-2'
 SUPPORTED_ELLIPSESCAP = (ELLIPSESCAP1, ELLIPSESCAP)
 
 # All available wire protocol transports.
 TRANSPORTS = {
-    SSHV1: {'transport': 'ssh', 'version': 1,},
+    SSHV1: {b'transport': b'ssh', b'version': 1,},
     SSHV2: {
-        'transport': 'ssh',
+        b'transport': b'ssh',
         # TODO mark as version 2 once all commands are implemented.
-        'version': 1,
+        b'version': 1,
     },
-    'http-v1': {'transport': 'http', 'version': 1,},
-    HTTP_WIREPROTO_V2: {'transport': 'http', 'version': 2,},
+    b'http-v1': {b'transport': b'http', b'version': 1,},
+    HTTP_WIREPROTO_V2: {b'transport': b'http', b'version': 2,},
 }
 
 
@@ -116,13 +116,13 @@
 
 
 # list of nodes encoding / decoding
-def decodelist(l, sep=' '):
+def decodelist(l, sep=b' '):
     if l:
         return [bin(v) for v in l.split(sep)]
     return []
 
 
-def encodelist(l, sep=' '):
+def encodelist(l, sep=b' '):
     try:
         return sep.join(map(hex, l))
     except TypeError:
@@ -134,19 +134,19 @@
 
 def escapebatcharg(plain):
     return (
-        plain.replace(':', ':c')
-        .replace(',', ':o')
-        .replace(';', ':s')
-        .replace('=', ':e')
+        plain.replace(b':', b':c')
+        .replace(b',', b':o')
+        .replace(b';', b':s')
+        .replace(b'=', b':e')
     )
 
 
 def unescapebatcharg(escaped):
     return (
-        escaped.replace(':e', '=')
-        .replace(':s', ';')
-        .replace(':o', ',')
-        .replace(':c', ':')
+        escaped.replace(b':e', b'=')
+        .replace(b':s', b';')
+        .replace(b':o', b',')
+        .replace(b':c', b':')
     )
 
 
@@ -162,18 +162,18 @@
 # :scsv:  set of values, transmitted as comma-separated values
 # :plain: string with no transformation needed.
 GETBUNDLE_ARGUMENTS = {
-    'heads': 'nodes',
-    'bookmarks': 'boolean',
-    'common': 'nodes',
-    'obsmarkers': 'boolean',
-    'phases': 'boolean',
-    'bundlecaps': 'scsv',
-    'listkeys': 'csv',
-    'cg': 'boolean',
-    'cbattempted': 'boolean',
-    'stream': 'boolean',
-    'includepats': 'csv',
-    'excludepats': 'csv',
+    b'heads': b'nodes',
+    b'bookmarks': b'boolean',
+    b'common': b'nodes',
+    b'obsmarkers': b'boolean',
+    b'phases': b'boolean',
+    b'bundlecaps': b'scsv',
+    b'listkeys': b'csv',
+    b'cg': b'boolean',
+    b'cbattempted': b'boolean',
+    b'stream': b'boolean',
+    b'includepats': b'csv',
+    b'excludepats': b'csv',
 }
 
 
@@ -253,9 +253,9 @@
     def __init__(
         self,
         func,
-        args='',
+        args=b'',
         transports=None,
-        permission='push',
+        permission=b'push',
         cachekeyfn=None,
         extracapabilitiesfn=None,
     ):
@@ -292,7 +292,7 @@
         elif i == 1:
             return self.args
         else:
-            raise IndexError('can only access elements 0 and 1')
+            raise IndexError(b'can only access elements 0 and 1')
 
 
 class commanddict(dict):
@@ -308,7 +308,7 @@
         # Cast 2-tuples to commandentry instances.
         elif isinstance(v, tuple):
             if len(v) != 2:
-                raise ValueError('command tuples must have exactly 2 elements')
+                raise ValueError(b'command tuples must have exactly 2 elements')
 
             # It is common for extensions to wrap wire protocol commands via
             # e.g. ``wireproto.commands[x] = (newfn, args)``. Because callers
@@ -322,11 +322,12 @@
                     v[0],
                     args=v[1],
                     transports=set(TRANSPORTS),
-                    permission='push',
+                    permission=b'push',
                 )
         else:
             raise ValueError(
-                'command entries must be commandentry instances ' 'or 2-tuples'
+                b'command entries must be commandentry instances '
+                b'or 2-tuples'
             )
 
         return super(commanddict, self).__setitem__(k, v)
@@ -354,8 +355,8 @@
 
     # Allow config to override default list and ordering.
     if role == compression.SERVERROLE:
-        configengines = ui.configlist('server', 'compressionengines')
-        config = 'server.compressionengines'
+        configengines = ui.configlist(b'server', b'compressionengines')
+        config = b'server.compressionengines'
     else:
         # This is currently implemented mainly to facilitate testing. In most
         # cases, the server should be in charge of choosing a compression engine
@@ -363,14 +364,16 @@
         # CPU DoS due to an expensive engine or a network DoS due to poor
         # compression ratio).
         configengines = ui.configlist(
-            'experimental', 'clientcompressionengines'
+            b'experimental', b'clientcompressionengines'
         )
-        config = 'experimental.clientcompressionengines'
+        config = b'experimental.clientcompressionengines'
 
     # No explicit config. Filter out the ones that aren't supposed to be
     # advertised and return default ordering.
     if not configengines:
-        attr = 'serverpriority' if role == util.SERVERROLE else 'clientpriority'
+        attr = (
+            b'serverpriority' if role == util.SERVERROLE else b'clientpriority'
+        )
         return [
             e for e in compengines if getattr(e.wireprotosupport(), attr) > 0
         ]
@@ -383,8 +386,8 @@
     invalidnames = set(e for e in configengines if e not in validnames)
     if invalidnames:
         raise error.Abort(
-            _('invalid compression engine defined in %s: %s')
-            % (config, ', '.join(sorted(invalidnames)))
+            _(b'invalid compression engine defined in %s: %s')
+            % (config, b', '.join(sorted(invalidnames)))
         )
 
     compengines = [e for e in compengines if e.name() in configengines]
@@ -395,11 +398,12 @@
     if not compengines:
         raise error.Abort(
             _(
-                '%s config option does not specify any known '
-                'compression engines'
+                b'%s config option does not specify any known '
+                b'compression engines'
             )
             % config,
-            hint=_('usable compression engines: %s') % ', '.sorted(validnames),
+            hint=_(b'usable compression engines: %s')
+            % b', '.sorted(validnames),
         )
 
     return compengines