Preliminarly works under py3

mercurial_keyring.py

@@ -184,12 +184,23 b' class PasswordStore(object):'
 
     def clear_http_password(self, url, username):
         """Drops saved password"""
-        self.set_http_password(url, username, "")
+        self.set_http_password(url, username, b"")
 
     @staticmethod
     def _format_http_key(url, username):
         """Construct actual key for password identification"""
-        return "%s@@%s" % (username, url)
+        # keyring expects str, mercurial feeds as here mostly with bytes
+        key = "%s@@%s" % (meu.pycompat.sysstr(username),
+                          meu.pycompat.sysstr(url))
+        return key
+
+    @staticmethod
+    def _format_smtp_key(machine, port, username):
+        """Construct key for SMTP password identification"""
+        key = "%s@@%s:%s" % (meu.pycompat.sysstr(username),
+                             meu.pycompat.sysstr(machine),
+                             str(port))
+        return key
 
     def get_smtp_password(self, machine, port, username):
         """Checks for SMTP password in keyring, returns
@@ -208,11 +219,6 b' class PasswordStore(object):'
         self.set_smtp_password(machine, port, username, "")
 
     @staticmethod
-    def _format_smtp_key(machine, port, username):
-        """Construct key for SMTP password identification"""
-        return "%s@@%s:%s" % (username, machine, str(port))
-
-    @staticmethod
     def _read_password_from_keyring(pwdkey):
         """Physically read from keyring"""
         keyring = import_keyring()
@@ -220,9 +226,10 b' class PasswordStore(object):'
             password = keyring.get_password(KEYRING_SERVICE, pwdkey)
         except Exception as err:
             ui = uimod.ui()
-            ui.warn(meu.ui_string("keyring: keyring backend doesn't seem to work, password can not be restored. Falling back to prompts. Error details: %s\n",
-                                  err))
-            return ''
+            ui.warn(meu.ui_string(
+                "keyring: keyring backend doesn't seem to work, password can not be restored. Falling back to prompts. Error details: %s\n",
+                err))
+            return b''
         # Reverse recoding from next routine
         if isinstance(password, meu.pycompat.unicode):
             return encoding.tolocal(password.encode('utf-8'))
@@ -841,7 +848,7 b' def cmd_keyring_clear(ui, repo, path, **'
     of path alias (``bitbucket``).
     """
     path_url = path
-    for name, url in ui.configitems('paths'):
+    for name, url in ui.configitems(b'paths'):
         if name == path:
             path_url = url
             break