Return [] for none-values for configtypes.List

qutebrowser/browser/adblock.py

@@ -67,11 +67,7 @@ def is_whitelisted_host(host):
     Args:
         host: The host of the request as string.
     """
-    whitelist = config.val.content.host_blocking.whitelist
-    if whitelist is None:
-        return False
-
-    for pattern in whitelist:
+    for pattern in config.val.content.host_blocking.whitelist:
         if fnmatch.fnmatch(host, pattern.lower()):
             return True
     return False
@@ -164,7 +160,7 @@ class HostBlocker:
 
         if not found:
             args = objreg.get('args')
-            if (config.val.content.host_blocking.lists is not None and
+            if (config.val.content.host_blocking.lists and
                     args.basedir is None and
                     config.val.content.host_blocking.enabled):
                 message.info("Run :adblock-update to get adblock lists.")
@@ -180,12 +176,9 @@ class HostBlocker:
                               self._config_blocked_hosts)
         self._blocked_hosts = set()
         self._done_count = 0
-        urls = config.val.content.host_blocking.lists
         download_manager = objreg.get('qtnetwork-download-manager',
                                       scope='window', window='last-focused')
-        if urls is None:
-            return
-        for url in urls:
+        for url in config.val.content.host_blocking.lists:
             if url.scheme() == 'file':
                 try:
                     fileobj = open(url.path(), 'rb')
@@ -295,7 +288,7 @@ class HostBlocker:
     @config.change_filter('content.host_blocking.lists')
     def _update_files(self):
         """Update files when the config changed."""
-        if config.val.content.host_blocking.lists is None:
+        if not config.val.content.host_blocking.lists:
             try:
                 os.remove(self._local_hosts_file)
             except FileNotFoundError:

qutebrowser/config/configdata.yml

@@ -915,7 +915,7 @@ keyhint.blacklist:
     none_ok: true
     valtype:
       name: String
-  default: null
+  default: []
   desc: >-
     Keychains that shouldn\'t be shown in the keyhint dialog.
 

qutebrowser/config/configtypes.py

@@ -388,6 +388,18 @@ class List(BaseType):
         self.valtype = valtype
         self.length = length
 
+    def _none_value(self, value=None):
+        """Return the value to be used when the setting is None.
+
+        Args:
+            value: An existing value to be returned.
+        """
+        if value is None:
+            return []
+        else:
+            assert value == [], value
+            return value
+
     def get_name(self):
         name = super().get_name()
         if self._show_valtype:
@@ -400,7 +412,7 @@ class List(BaseType):
     def from_str(self, value):
         self._basic_str_validation(value)
         if not value:
-            return None
+            return self._none_value()
 
         try:
             yaml_val = utils.yaml_load(value)
@@ -415,7 +427,7 @@ class List(BaseType):
     def to_py(self, value):
         self._basic_py_validation(value, list)
         if not value:
-            return None
+            return self._none_value(value)
 
         if self.length is not None and len(value) != self.length:
             raise configexc.ValidationError(value, "Exactly {} values need to "
@@ -452,8 +464,7 @@ class FlagList(List):
 
     def to_py(self, value):
         vals = super().to_py(value)
-        if vals is not None:
-            self._check_duplicates(vals)
+        self._check_duplicates(vals)
         return vals
 
     def complete(self):
@@ -1038,7 +1049,7 @@ class Dict(BaseType):
         """Return the value to be used when the setting is None.
 
         Args:
-            value: An existing value to be mutated when given.
+            value: An existing value to be returned.
         """
         if self.fixed_keys is None:
             if value is None:
@@ -1179,7 +1190,8 @@ class ShellCommand(List):
     def from_str(self, value):
         self._basic_str_validation(value)
         if not value:
-            return None
+            return self._none_value()
+
         try:
             split_val = shlex.split(value)
         except ValueError as e:
@@ -1191,7 +1203,7 @@ class ShellCommand(List):
     def to_py(self, value):
         value = super().to_py(value)
         if not value:
-            return None
+            return value
 
         if self.placeholder and '{}' not in ' '.join(value):
             raise configexc.ValidationError(value, "needs to contain a "
@@ -1439,7 +1451,7 @@ class ConfirmQuit(FlagList):
     def to_py(self, value):
         values = super().to_py(value)
         if not values:
-            return None
+            return values
 
         # Never can't be set with other options
         if 'never' in values and len(values) > 1:

qutebrowser/misc/keyhintwidget.py

@@ -90,11 +90,9 @@ class KeyHintView(QLabel):
             self.hide()
             return
 
-        blacklist = config.val.keyhint.blacklist or []
-
         def blacklisted(keychain):
             return any(fnmatch.fnmatchcase(keychain, glob)
-                       for glob in blacklist)
+                       for glob in config.val.keyhint.blacklist)
 
         bindings_dict = config.key_instance.get_bindings_for(modename)
         if not bindings_dict:

tests/unit/config/test_configtypes.py

@@ -252,7 +252,7 @@ class TestAll:
     def test_none_ok_true(self, klass):
         """Test None and empty string values with none_ok=True."""
         typ = klass(none_ok=True)
-        if isinstance(typ, configtypes.Dict):
+        if isinstance(typ, (configtypes.Dict, configtypes.List)):
             expected = typ._none_value()
         else:
             expected = None