From 81d67f8a2c618a3cf84ec70703c5379f20a91217 Mon Sep 17 00:00:00 2001
From: Florian Bruhin <git@the-compiler.org>
Date: Mon, 14 Nov 2016 08:31:06 +0100
Subject: [PATCH] Remove support for an empty data/config/cachedir

See #2115
---
 doc/qutebrowser.1.asciidoc                   |  6 +-
 qutebrowser/browser/adblock.py               | 21 ++-----
 qutebrowser/browser/history.py               |  8 ---
 qutebrowser/browser/urlmarks.py              | 13 +---
 qutebrowser/browser/webkit/cache.py          | 16 +----
 qutebrowser/browser/webkit/webkitsettings.py | 17 +++---
 qutebrowser/commands/userscripts.py          | 14 ++---
 qutebrowser/config/config.py                 | 59 ++++++++----------
 qutebrowser/config/configtypes.py            | 20 +-----
 qutebrowser/config/parsers/ini.py            |  7 +--
 qutebrowser/config/parsers/keyconf.py        | 10 +--
 qutebrowser/misc/crashsignal.py              | 10 +--
 qutebrowser/misc/lineparser.py               |  9 +--
 qutebrowser/misc/sessions.py                 | 23 ++-----
 qutebrowser/qutebrowser.py                   | 16 +++--
 qutebrowser/utils/standarddir.py             | 32 +++++-----
 tests/end2end/test_invocations.py            | 18 ------
 tests/unit/browser/test_adblock.py           | 27 ---------
 tests/unit/browser/webkit/test_cache.py      | 10 ---
 tests/unit/browser/webkit/test_history.py    |  7 ---
 tests/unit/config/test_config.py             | 64 +++-----------------
 tests/unit/config/test_configtypes.py        | 16 +----
 tests/unit/misc/test_lineparser.py           | 26 --------
 tests/unit/misc/test_sessions.py             | 31 +---------
 tests/unit/utils/test_standarddir.py         | 22 ++-----
 25 files changed, 110 insertions(+), 392 deletions(-)

diff --git a/doc/qutebrowser.1.asciidoc b/doc/qutebrowser.1.asciidoc
index c0d2b577a..8b856ccb3 100644
--- a/doc/qutebrowser.1.asciidoc
+++ b/doc/qutebrowser.1.asciidoc
@@ -39,13 +39,13 @@ show it.
     show this help message and exit
 
 *-c* 'CONFDIR', *--confdir* 'CONFDIR'::
-    Set config directory (empty for no config storage).
+    Set config directory
 
 *--datadir* 'DATADIR'::
-    Set data directory (empty for no data storage).
+    Set data directory
 
 *--cachedir* 'CACHEDIR'::
-    Set cache directory (empty for no cache storage).
+    Set cache directory
 
 *--basedir* 'BASEDIR'::
     Base directory for all storage. Other --*dir arguments are ignored if this is given.
diff --git a/qutebrowser/browser/adblock.py b/qutebrowser/browser/adblock.py
index 84d630ab6..06d0cabe8 100644
--- a/qutebrowser/browser/adblock.py
+++ b/qutebrowser/browser/adblock.py
@@ -29,7 +29,7 @@ import fnmatch
 from qutebrowser.browser import downloads
 from qutebrowser.config import config
 from qutebrowser.utils import objreg, standarddir, log, message
-from qutebrowser.commands import cmdutils, cmdexc
+from qutebrowser.commands import cmdutils
 
 
 def guess_zip_filename(zf):
@@ -113,17 +113,11 @@ class HostBlocker:
         self._done_count = 0
 
         data_dir = standarddir.data()
-        if data_dir is None:
-            self._local_hosts_file = None
-        else:
-            self._local_hosts_file = os.path.join(data_dir, 'blocked-hosts')
+        self._local_hosts_file = os.path.join(data_dir, 'blocked-hosts')
         self.on_config_changed()
 
         config_dir = standarddir.config()
-        if config_dir is None:
-            self._config_hosts_file = None
-        else:
-            self._config_hosts_file = os.path.join(config_dir, 'blocked-hosts')
+        self._config_hosts_file = os.path.join(config_dir, 'blocked-hosts')
 
         objreg.get('config').changed.connect(self.on_config_changed)
 
@@ -146,7 +140,7 @@ class HostBlocker:
         Return:
             True if a read was attempted, False otherwise
         """
-        if filename is None or not os.path.exists(filename):
+        if not os.path.exists(filename):
             return False
 
         try:
@@ -162,9 +156,6 @@ class HostBlocker:
         """Read hosts from the existing blocked-hosts file."""
         self._blocked_hosts = set()
 
-        if self._local_hosts_file is None:
-            return
-
         self._read_hosts_file(self._config_hosts_file,
                               self._config_blocked_hosts)
 
@@ -186,8 +177,6 @@ class HostBlocker:
         """
         self._read_hosts_file(self._config_hosts_file,
                               self._config_blocked_hosts)
-        if self._local_hosts_file is None:
-            raise cmdexc.CommandError("No data storage is configured!")
         self._blocked_hosts = set()
         self._done_count = 0
         urls = config.get('content', 'host-block-lists')
@@ -275,7 +264,7 @@ class HostBlocker:
     def on_config_changed(self):
         """Update files when the config changed."""
         urls = config.get('content', 'host-block-lists')
-        if urls is None and self._local_hosts_file is not None:
+        if urls is None:
             try:
                 os.remove(self._local_hosts_file)
             except FileNotFoundError:
diff --git a/qutebrowser/browser/history.py b/qutebrowser/browser/history.py
index 4e2e126f6..c9008548a 100644
--- a/qutebrowser/browser/history.py
+++ b/qutebrowser/browser/history.py
@@ -129,7 +129,6 @@ class WebHistory(QObject):
 
     Attributes:
         history_dict: An OrderedDict of URLs read from the on-disk history.
-        _hist_dir: The directory to store the history in
         _lineparser: The AppendLineParser used to save the history.
         _new_history: A list of Entry items of the current session.
         _saved_count: How many HistoryEntries have been written to disk.
@@ -157,7 +156,6 @@ class WebHistory(QObject):
         super().__init__(parent)
         self._initial_read_started = False
         self._initial_read_done = False
-        self._hist_dir = hist_dir
         self._lineparser = lineparser.AppendLineParser(hist_dir, hist_name,
                                                        parent=self)
         self.history_dict = collections.OrderedDict()
@@ -183,12 +181,6 @@ class WebHistory(QObject):
             return
         self._initial_read_started = True
 
-        if self._hist_dir is None:
-            self._initial_read_done = True
-            self.async_read_done.emit()
-            assert not self._temp_history
-            return
-
         with self._lineparser.open():
             for line in self._lineparser:
                 yield
diff --git a/qutebrowser/browser/urlmarks.py b/qutebrowser/browser/urlmarks.py
index fc727a284..991ba7fc5 100644
--- a/qutebrowser/browser/urlmarks.py
+++ b/qutebrowser/browser/urlmarks.py
@@ -73,8 +73,7 @@ class UrlMarkManager(QObject):
 
     Attributes:
         marks: An OrderedDict of all quickmarks/bookmarks.
-        _lineparser: The LineParser used for the marks, or None
-                     (when qutebrowser is started with -c '').
+        _lineparser: The LineParser used for the marks
 
     Signals:
         changed: Emitted when anything changed.
@@ -91,10 +90,6 @@ class UrlMarkManager(QObject):
         super().__init__(parent)
 
         self.marks = collections.OrderedDict()
-        self._lineparser = None
-
-        if standarddir.config() is None:
-            return
 
         self._init_lineparser()
         for line in self._lineparser:
@@ -115,10 +110,8 @@ class UrlMarkManager(QObject):
 
     def save(self):
         """Save the marks to disk."""
-        if self._lineparser is not None:
-            self._lineparser.data = [' '.join(tpl)
-                                     for tpl in self.marks.items()]
-            self._lineparser.save()
+        self._lineparser.data = [' '.join(tpl) for tpl in self.marks.items()]
+        self._lineparser.save()
 
     def delete(self, key):
         """Delete a quickmark/bookmark.
diff --git a/qutebrowser/browser/webkit/cache.py b/qutebrowser/browser/webkit/cache.py
index 1270498e4..bc774c250 100644
--- a/qutebrowser/browser/webkit/cache.py
+++ b/qutebrowser/browser/webkit/cache.py
@@ -32,23 +32,14 @@ class DiskCache(QNetworkDiskCache):
 
     """Disk cache which sets correct cache dir and size.
 
-    If the cache is deactivated via the command line argument --cachedir="",
-    both attributes _cache_dir and _http_cache_dir are set to None.
-
     Attributes:
         _activated: Whether the cache should be used.
-        _cache_dir: The base directory for cache files (standarddir.cache()) or
-                    None.
-        _http_cache_dir: the HTTP subfolder in _cache_dir or None.
+        _cache_dir: The base directory for cache files (standarddir.cache())
     """
 
     def __init__(self, cache_dir, parent=None):
         super().__init__(parent)
         self._cache_dir = cache_dir
-        if cache_dir is None:
-            self._http_cache_dir = None
-        else:
-            self._http_cache_dir = os.path.join(cache_dir, 'http')
         self._maybe_activate()
         objreg.get('config').changed.connect(self.on_config_changed)
 
@@ -59,12 +50,11 @@ class DiskCache(QNetworkDiskCache):
 
     def _maybe_activate(self):
         """Activate/deactivate the cache based on the config."""
-        if (config.get('general', 'private-browsing') or
-                self._cache_dir is None):
+        if config.get('general', 'private-browsing'):
             self._activated = False
         else:
             self._activated = True
-            self.setCacheDirectory(self._http_cache_dir)
+            self.setCacheDirectory(os.path.join(self._cache_dir, 'http'))
             self.setMaximumCacheSize(config.get('storage', 'cache-size'))
 
     @pyqtSlot(str, str)
diff --git a/qutebrowser/browser/webkit/webkitsettings.py b/qutebrowser/browser/webkit/webkitsettings.py
index ffb394872..86505162f 100644
--- a/qutebrowser/browser/webkit/webkitsettings.py
+++ b/qutebrowser/browser/webkit/webkitsettings.py
@@ -95,18 +95,17 @@ def init():
     """Initialize the global QWebSettings."""
     cache_path = standarddir.cache()
     data_path = standarddir.data()
-    if config.get('general', 'private-browsing') or cache_path is None:
+    if config.get('general', 'private-browsing'):
         QWebSettings.setIconDatabasePath('')
     else:
         QWebSettings.setIconDatabasePath(cache_path)
-    if cache_path is not None:
-        QWebSettings.setOfflineWebApplicationCachePath(
-            os.path.join(cache_path, 'application-cache'))
-    if data_path is not None:
-        QWebSettings.globalSettings().setLocalStoragePath(
-            os.path.join(data_path, 'local-storage'))
-        QWebSettings.setOfflineStoragePath(
-            os.path.join(data_path, 'offline-storage'))
+
+    QWebSettings.setOfflineWebApplicationCachePath(
+        os.path.join(cache_path, 'application-cache'))
+    QWebSettings.globalSettings().setLocalStoragePath(
+        os.path.join(data_path, 'local-storage'))
+    QWebSettings.setOfflineStoragePath(
+        os.path.join(data_path, 'offline-storage'))
 
     websettings.init_mappings(MAPPINGS)
     objreg.get('config').changed.connect(update_settings)
diff --git a/qutebrowser/commands/userscripts.py b/qutebrowser/commands/userscripts.py
index d939d6928..3c1d4d89e 100644
--- a/qutebrowser/commands/userscripts.py
+++ b/qutebrowser/commands/userscripts.py
@@ -408,15 +408,11 @@ def run_async(tab, cmd, *args, win_id, env, verbose=False):
     user_agent = config.get('network', 'user-agent')
     if user_agent is not None:
         env['QUTE_USER_AGENT'] = user_agent
-    config_dir = standarddir.config()
-    if config_dir is not None:
-        env['QUTE_CONFIG_DIR'] = config_dir
-    data_dir = standarddir.data()
-    if data_dir is not None:
-        env['QUTE_DATA_DIR'] = data_dir
-    download_dir = downloads.download_dir()
-    if download_dir is not None:
-        env['QUTE_DOWNLOAD_DIR'] = download_dir
+
+    env['QUTE_CONFIG_DIR'] = standarddir.config()
+    env['QUTE_DATA_DIR'] = standarddir.data()
+    env['QUTE_DOWNLOAD_DIR'] = downloads.download_dir()
+
     cmd_path = os.path.expanduser(cmd)
 
     # if cmd is not given as an absolute path, look it up
diff --git a/qutebrowser/config/config.py b/qutebrowser/config/config.py
index 2cfea1510..38d8aa6eb 100644
--- a/qutebrowser/config/config.py
+++ b/qutebrowser/config/config.py
@@ -160,19 +160,18 @@ def _init_main_config(parent=None):
         sys.exit(usertypes.Exit.err_config)
     else:
         objreg.register('config', config_obj)
-        if standarddir.config() is not None:
-            filename = os.path.join(standarddir.config(), 'qutebrowser.conf')
-            save_manager = objreg.get('save-manager')
-            save_manager.add_saveable(
-                'config', config_obj.save, config_obj.changed,
-                config_opt=('general', 'auto-save-config'), filename=filename)
-            for sect in config_obj.sections.values():
-                for opt in sect.values.values():
-                    if opt.values['conf'] is None:
-                        # Option added to built-in defaults but not in user's
-                        # config yet
-                        save_manager.save('config', explicit=True, force=True)
-                        return
+        filename = os.path.join(standarddir.config(), 'qutebrowser.conf')
+        save_manager = objreg.get('save-manager')
+        save_manager.add_saveable(
+            'config', config_obj.save, config_obj.changed,
+            config_opt=('general', 'auto-save-config'), filename=filename)
+        for sect in config_obj.sections.values():
+            for opt in sect.values.values():
+                if opt.values['conf'] is None:
+                    # Option added to built-in defaults but not in user's
+                    # config yet
+                    save_manager.save('config', explicit=True, force=True)
+                    return
 
 
 def _init_key_config(parent):
@@ -197,13 +196,12 @@ def _init_key_config(parent):
         sys.exit(usertypes.Exit.err_key_config)
     else:
         objreg.register('key-config', key_config)
-        if standarddir.config() is not None:
-            save_manager = objreg.get('save-manager')
-            filename = os.path.join(standarddir.config(), 'keys.conf')
-            save_manager.add_saveable(
-                'key-config', key_config.save, key_config.config_dirty,
-                config_opt=('general', 'auto-save-config'), filename=filename,
-                dirty=key_config.is_dirty)
+        save_manager = objreg.get('save-manager')
+        filename = os.path.join(standarddir.config(), 'keys.conf')
+        save_manager.add_saveable(
+            'key-config', key_config.save, key_config.config_dirty,
+            config_opt=('general', 'auto-save-config'), filename=filename,
+            dirty=key_config.is_dirty)
 
 
 def _init_misc():
@@ -237,10 +235,7 @@ def _init_misc():
     # This fixes one of the corruption issues here:
     # https://github.com/The-Compiler/qutebrowser/issues/515
 
-    if standarddir.config() is None:
-        path = os.devnull
-    else:
-        path = os.path.join(standarddir.config(), 'qsettings')
+    path = os.path.join(standarddir.config(), 'qsettings')
     for fmt in [QSettings.NativeFormat, QSettings.IniFormat]:
         QSettings.setPath(fmt, QSettings.UserScope, path)
 
@@ -659,15 +654,11 @@ class ConfigManager(QObject):
     def read(self, configdir, fname, relaxed=False):
         """Read the config from the given directory/file."""
         self._fname = fname
-        if configdir is None:
-            self._configdir = None
-            self._initialized = True
-        else:
-            self._configdir = configdir
-            parser = ini.ReadConfigParser(configdir, fname)
-            self._from_cp(parser, relaxed)
-            self._initialized = True
-            self._validate_all()
+        self._configdir = configdir
+        parser = ini.ReadConfigParser(configdir, fname)
+        self._from_cp(parser, relaxed)
+        self._initialized = True
+        self._validate_all()
 
     def items(self, sectname, raw=True):
         """Get a list of (optname, value) tuples for a section.
@@ -884,8 +875,6 @@ class ConfigManager(QObject):
 
     def save(self):
         """Save the config file."""
-        if self._configdir is None:
-            return
         configfile = os.path.join(self._configdir, self._fname)
         log.destroy.debug("Saving config to {}".format(configfile))
         with qtutils.savefile_open(configfile) as f:
diff --git a/qutebrowser/config/configtypes.py b/qutebrowser/config/configtypes.py
index 346b5a8d7..0642b79e8 100644
--- a/qutebrowser/config/configtypes.py
+++ b/qutebrowser/config/configtypes.py
@@ -859,9 +859,7 @@ class File(BaseType):
         value = os.path.expanduser(value)
         value = os.path.expandvars(value)
         if not os.path.isabs(value):
-            cfgdir = standarddir.config()
-            assert cfgdir is not None
-            value = os.path.join(cfgdir, value)
+            value = os.path.join(standarddir.config(), value)
         return value
 
     def validate(self, value):
@@ -872,12 +870,7 @@ class File(BaseType):
         value = os.path.expandvars(value)
         try:
             if not os.path.isabs(value):
-                cfgdir = standarddir.config()
-                if cfgdir is None:
-                    raise configexc.ValidationError(
-                        value, "must be an absolute path when not using a "
-                        "config directory!")
-                value = os.path.join(cfgdir, value)
+                value = os.path.join(standarddir.config(), value)
                 not_isfile_message = ("must be a valid path relative to the "
                                       "config directory!")
             else:
@@ -1180,14 +1173,7 @@ class UserStyleSheet(File):
         if not value:
             return None
 
-        if standarddir.config() is None:
-            # We can't call super().transform() here as this counts on the
-            # validation previously ensuring that we don't have a relative path
-            # when starting with -c "".
-            path = None
-        else:
-            path = super().transform(value)
-
+        path = super().transform(value)
         if path is not None and os.path.exists(path):
             return QUrl.fromLocalFile(path)
         else:
diff --git a/qutebrowser/config/parsers/ini.py b/qutebrowser/config/parsers/ini.py
index 90ca27c50..56640e299 100644
--- a/qutebrowser/config/parsers/ini.py
+++ b/qutebrowser/config/parsers/ini.py
@@ -47,15 +47,12 @@ class ReadConfigParser(configparser.ConfigParser):
         self.optionxform = lambda opt: opt  # be case-insensitive
         self._configdir = configdir
         self._fname = fname
-        if self._configdir is None:
-            self._configfile = None
-            return
         self._configfile = os.path.join(self._configdir, fname)
+
         if not os.path.isfile(self._configfile):
             return
         log.init.debug("Reading config from {}".format(self._configfile))
-        if self._configfile is not None:
-            self.read(self._configfile, encoding='utf-8')
+        self.read(self._configfile, encoding='utf-8')
 
     def __repr__(self):
         return utils.get_repr(self, constructor=True,
diff --git a/qutebrowser/config/parsers/keyconf.py b/qutebrowser/config/parsers/keyconf.py
index aa1600ae1..e602c33d5 100644
--- a/qutebrowser/config/parsers/keyconf.py
+++ b/qutebrowser/config/parsers/keyconf.py
@@ -89,11 +89,9 @@ class KeyConfigParser(QObject):
         self._cur_command = None
         # Mapping of section name(s) to key binding -> command dicts.
         self.keybindings = collections.OrderedDict()
-        if configdir is None:
-            self._configfile = None
-        else:
-            self._configfile = os.path.join(configdir, fname)
-        if self._configfile is None or not os.path.exists(self._configfile):
+        self._configfile = os.path.join(configdir, fname)
+
+        if not os.path.exists(self._configfile):
             self._load_default()
         else:
             self._read(relaxed)
@@ -143,8 +141,6 @@ class KeyConfigParser(QObject):
 
     def save(self):
         """Save the key config file."""
-        if self._configfile is None:
-            return
         log.destroy.debug("Saving key config to {}".format(self._configfile))
         with qtutils.savefile_open(self._configfile, encoding='utf-8') as f:
             data = str(self)
diff --git a/qutebrowser/misc/crashsignal.py b/qutebrowser/misc/crashsignal.py
index b970e467b..35c39bf2e 100644
--- a/qutebrowser/misc/crashsignal.py
+++ b/qutebrowser/misc/crashsignal.py
@@ -72,10 +72,7 @@ class CrashHandler(QObject):
 
     def handle_segfault(self):
         """Handle a segfault from a previous run."""
-        data_dir = standarddir.data()
-        if data_dir is None:
-            return
-        logname = os.path.join(data_dir, 'crash.log')
+        logname = os.path.join(standarddir.data(), 'crash.log')
         try:
             # First check if an old logfile exists.
             if os.path.exists(logname):
@@ -131,10 +128,7 @@ class CrashHandler(QObject):
     def _init_crashlogfile(self):
         """Start a new logfile and redirect faulthandler to it."""
         assert not self._args.no_err_windows
-        data_dir = standarddir.data()
-        if data_dir is None:
-            return
-        logname = os.path.join(data_dir, 'crash.log')
+        logname = os.path.join(standarddir.data(), 'crash.log')
         try:
             self._crash_log_file = open(logname, 'w', encoding='ascii')
         except OSError:
diff --git a/qutebrowser/misc/lineparser.py b/qutebrowser/misc/lineparser.py
index 4999c2e22..55bae7142 100644
--- a/qutebrowser/misc/lineparser.py
+++ b/qutebrowser/misc/lineparser.py
@@ -57,10 +57,7 @@ class BaseLineParser(QObject):
         """
         super().__init__(parent)
         self._configdir = configdir
-        if self._configdir is None:
-            self._configfile = None
-        else:
-            self._configfile = os.path.join(self._configdir, fname)
+        self._configfile = os.path.join(self._configdir, fname)
         self._fname = fname
         self._binary = binary
         self._opened = False
@@ -76,8 +73,6 @@ class BaseLineParser(QObject):
         Return:
             True if the file should be saved, False otherwise.
         """
-        if self._configdir is None:
-            return False
         if not os.path.exists(self._configdir):
             os.makedirs(self._configdir, 0o755)
         return True
@@ -222,7 +217,7 @@ class LineParser(BaseLineParser):
             binary: Whether to open the file in binary mode.
         """
         super().__init__(configdir, fname, binary=binary, parent=parent)
-        if configdir is None or not os.path.isfile(self._configfile):
+        if not os.path.isfile(self._configfile):
             self.data = []
         else:
             log.init.debug("Reading {}".format(self._configfile))
diff --git a/qutebrowser/misc/sessions.py b/qutebrowser/misc/sessions.py
index c3a3a8e34..9a544c738 100644
--- a/qutebrowser/misc/sessions.py
+++ b/qutebrowser/misc/sessions.py
@@ -47,15 +47,11 @@ def init(parent=None):
     Args:
         parent: The parent to use for the SessionManager.
     """
-    data_dir = standarddir.data()
-    if data_dir is None:
-        base_path = None
-    else:
-        base_path = os.path.join(standarddir.data(), 'sessions')
-        try:
-            os.mkdir(base_path)
-        except FileExistsError:
-            pass
+    base_path = os.path.join(standarddir.data(), 'sessions')
+    try:
+        os.mkdir(base_path)
+    except FileExistsError:
+        pass
 
     session_manager = SessionManager(base_path, parent)
     objreg.register('session-manager', session_manager)
@@ -137,11 +133,6 @@ class SessionManager(QObject):
         if os.path.isabs(path) and ((not check_exists) or
                                     os.path.exists(path)):
             return path
-        elif self._base_path is None:
-            if check_exists:
-                raise SessionNotFoundError(name)
-            else:
-                return None
         else:
             path = os.path.join(self._base_path, name + '.yml')
             if check_exists and not os.path.exists(path):
@@ -279,8 +270,6 @@ class SessionManager(QObject):
         """
         name = self._get_session_name(name)
         path = self._get_session_path(name)
-        if path is None:
-            raise SessionError("No data storage configured.")
 
         log.sessions.debug("Saving session {} to {}...".format(name, path))
         if last_window:
@@ -392,8 +381,6 @@ class SessionManager(QObject):
     def list_sessions(self):
         """Get a list of all session names."""
         sessions = []
-        if self._base_path is None:
-            return sessions
         for filename in os.listdir(self._base_path):
             base, ext = os.path.splitext(filename)
             if ext == '.yml':
diff --git a/qutebrowser/qutebrowser.py b/qutebrowser/qutebrowser.py
index 5a6d7e259..de80b972b 100644
--- a/qutebrowser/qutebrowser.py
+++ b/qutebrowser/qutebrowser.py
@@ -47,12 +47,11 @@ def get_argparser():
     """Get the argparse parser."""
     parser = argparse.ArgumentParser(prog='qutebrowser',
                                      description=qutebrowser.__description__)
-    parser.add_argument('-c', '--confdir', help="Set config directory (empty "
-                        "for no config storage).")
-    parser.add_argument('--datadir', help="Set data directory (empty for "
-                        "no data storage).")
-    parser.add_argument('--cachedir', help="Set cache directory (empty for "
-                        "no cache storage).")
+    parser.add_argument('-c', '--confdir', help="Set config directory",
+                        type=directory)
+    parser.add_argument('--datadir', help="Set data directory", type=directory)
+    parser.add_argument('--cachedir', help="Set cache directory",
+                        type=directory)
     parser.add_argument('--basedir', help="Base directory for all storage. "
                         "Other --*dir arguments are ignored if this is given.")
     parser.add_argument('-V', '--version', help="Show version and quit.",
@@ -124,6 +123,11 @@ def get_argparser():
     return parser
 
 
+def directory(arg):
+    if not arg:
+        raise argparse.ArgumentTypeError("Invalid empty value")
+
+
 def logfilter_error(logfilter: str):
     """Validate logger names passed to --logfilter.
 
diff --git a/qutebrowser/utils/standarddir.py b/qutebrowser/utils/standarddir.py
index 10929f251..cbfa2555c 100644
--- a/qutebrowser/utils/standarddir.py
+++ b/qutebrowser/utils/standarddir.py
@@ -43,7 +43,7 @@ def config():
             # WORKAROUND - see
             # https://bugreports.qt.io/browse/QTBUG-38872
             path = os.path.join(path, appname)
-    _maybe_create(path)
+    _create(path)
     return path
 
 
@@ -61,7 +61,7 @@ def data():
                 QStandardPaths.ConfigLocation)
             if data_path == config_path:
                 path = os.path.join(path, 'data')
-    _maybe_create(path)
+    _create(path)
     return path
 
 
@@ -82,7 +82,7 @@ def cache():
     overridden, path = _from_args(typ, _args)
     if not overridden:
         path = _writable_location(typ)
-    _maybe_create(path)
+    _create(path)
     return path
 
 
@@ -92,7 +92,7 @@ def download():
     overridden, path = _from_args(typ, _args)
     if not overridden:
         path = _writable_location(typ)
-    _maybe_create(path)
+    _create(path)
     return path
 
 
@@ -116,7 +116,7 @@ def runtime():
         # maximum length of 104 chars), so we don't add the username here...
         appname = QCoreApplication.instance().applicationName()
         path = os.path.join(path, appname)
-    _maybe_create(path)
+    _create(path)
     return path
 
 
@@ -175,16 +175,16 @@ def _from_args(typ, args):
     except KeyError:
         return (False, None)
     arg_value = getattr(args, argname)
+
+    assert arg_value != '', argname
     if arg_value is None:
         return (False, None)
-    elif arg_value == '':
-        return (True, None)
     else:
         return (True, arg_value)
 
 
-def _maybe_create(path):
-    """Create the `path` directory if path is not None.
+def _create(path):
+    """Create the `path` directory.
 
     From the XDG basedir spec:
         If, when attempting to write a file, the destination directory is
@@ -192,11 +192,10 @@ def _maybe_create(path):
         0700. If the destination directory exists already the permissions
         should not be changed.
     """
-    if path is not None:
-        try:
-            os.makedirs(path, 0o700)
-        except FileExistsError:
-            pass
+    try:
+        os.makedirs(path, 0o700)
+    except FileExistsError:
+        pass
 
 
 def init(args):
@@ -214,10 +213,7 @@ def _init_cachedir_tag():
 
     See http://www.brynosaurus.com/cachedir/spec.html
     """
-    cache_dir = cache()
-    if cache_dir is None:
-        return
-    cachedir_tag = os.path.join(cache_dir, 'CACHEDIR.TAG')
+    cachedir_tag = os.path.join(cache(), 'CACHEDIR.TAG')
     if not os.path.exists(cachedir_tag):
         try:
             with open(cachedir_tag, 'w', encoding='utf-8') as f:
diff --git a/tests/end2end/test_invocations.py b/tests/end2end/test_invocations.py
index fd414db12..d85e2a467 100644
--- a/tests/end2end/test_invocations.py
+++ b/tests/end2end/test_invocations.py
@@ -68,24 +68,6 @@ def temp_basedir_env(tmpdir, short_tmpdir):
     return env
 
 
-@pytest.mark.linux
-def test_no_config(request, temp_basedir_env, quteproc_new):
-    """Test starting with -c ""."""
-    args = ['-c', ''] + _base_args(request.config)
-    quteproc_new.start(args, env=temp_basedir_env)
-    quteproc_new.send_cmd(':quit')
-    quteproc_new.wait_for_quit()
-
-
-@pytest.mark.linux
-def test_no_cache(request, temp_basedir_env, quteproc_new):
-    """Test starting with --cachedir=""."""
-    args = ['--cachedir='] + _base_args(request.config)
-    quteproc_new.start(args, env=temp_basedir_env)
-    quteproc_new.send_cmd(':quit')
-    quteproc_new.wait_for_quit()
-
-
 @pytest.mark.linux
 def test_ascii_locale(request, httpbin, tmpdir, quteproc_new):
     """Test downloads with LC_ALL=C set.
diff --git a/tests/unit/browser/test_adblock.py b/tests/unit/browser/test_adblock.py
index b0285a8f5..3caf6e526 100644
--- a/tests/unit/browser/test_adblock.py
+++ b/tests/unit/browser/test_adblock.py
@@ -29,7 +29,6 @@ from PyQt5.QtCore import pyqtSignal, QUrl, QObject
 
 from qutebrowser.browser import adblock
 from qutebrowser.utils import objreg
-from qutebrowser.commands import cmdexc
 
 pytestmark = pytest.mark.usefixtures('qapp', 'config_tmpdir')
 
@@ -225,32 +224,6 @@ def generic_blocklists(directory):
     return [blocklist1, blocklist2, blocklist3, blocklist4, blocklist5]
 
 
-def test_without_datadir(config_stub, tmpdir, monkeypatch, win_registry):
-    """No directory for data configured so no hosts file exists.
-
-    Ensure CommandError is raised and no URL is blocked.
-    """
-    config_stub.data = {
-        'content': {
-            'host-block-lists': generic_blocklists(tmpdir),
-            'host-blocking-enabled': True,
-        }
-    }
-    monkeypatch.setattr('qutebrowser.utils.standarddir.data', lambda: None)
-    host_blocker = adblock.HostBlocker()
-
-    with pytest.raises(cmdexc.CommandError) as excinfo:
-        host_blocker.adblock_update()
-    assert str(excinfo.value) == "No data storage is configured!"
-
-    host_blocker.read_hosts()
-    for str_url in URLS_TO_CHECK:
-        assert not host_blocker.is_blocked(QUrl(str_url))
-
-    # To test on_config_changed
-    config_stub.set('content', 'host-block-lists', None)
-
-
 def test_disabled_blocking_update(basedir, config_stub, download_stub,
                                   data_tmpdir, tmpdir, win_registry, caplog):
     """Ensure no URL is blocked when host blocking is disabled."""
diff --git a/tests/unit/browser/webkit/test_cache.py b/tests/unit/browser/webkit/test_cache.py
index 1d9b8a684..c716b9b82 100644
--- a/tests/unit/browser/webkit/test_cache.py
+++ b/tests/unit/browser/webkit/test_cache.py
@@ -111,16 +111,6 @@ def test_cache_size_deactivated(config_stub, tmpdir):
     assert disk_cache.cacheSize() == 0
 
 
-def test_cache_no_cache_dir(config_stub):
-    """Confirm that the cache is deactivated when cache_dir is None."""
-    config_stub.data = {
-        'storage': {'cache-size': 1024},
-        'general': {'private-browsing': False},
-    }
-    disk_cache = cache.DiskCache(None)
-    assert disk_cache.cacheSize() == 0
-
-
 def test_cache_existing_metadata_file(config_stub, tmpdir):
     """Test querying existing meta data file from activated cache."""
     config_stub.data = {
diff --git a/tests/unit/browser/webkit/test_history.py b/tests/unit/browser/webkit/test_history.py
index c99adbb5a..7b2b6f53a 100644
--- a/tests/unit/browser/webkit/test_history.py
+++ b/tests/unit/browser/webkit/test_history.py
@@ -65,13 +65,6 @@ def test_async_read_twice(monkeypatch, qtbot, tmpdir, caplog):
     assert caplog.records[0].msg == expected
 
 
-def test_async_read_no_datadir(qtbot, config_stub, fake_save_manager):
-    config_stub.data = {'general': {'private-browsing': False}}
-    hist = history.WebHistory(hist_dir=None, hist_name='history')
-    with qtbot.waitSignal(hist.async_read_done):
-        list(hist.async_read())
-
-
 @pytest.mark.parametrize('redirect', [True, False])
 def test_adding_item_during_async_read(qtbot, hist, redirect):
     """Check what happens when adding URL while reading the history."""
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index 1253b6a0a..3b6f21f7d 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -23,9 +23,7 @@ import os.path
 import configparser
 import collections
 import shutil
-from unittest import mock
 
-from PyQt5.QtCore import QObject
 from PyQt5.QtGui import QColor
 import pytest
 
@@ -33,7 +31,6 @@ import qutebrowser
 from qutebrowser.config import config, configexc, configdata
 from qutebrowser.config.parsers import keyconf
 from qutebrowser.commands import runners
-from qutebrowser.utils import objreg, standarddir
 
 
 class TestConfigParser:
@@ -43,12 +40,12 @@ class TestConfigParser:
     Objects = collections.namedtuple('Objects', ['cp', 'cfg'])
 
     @pytest.fixture
-    def objects(self):
+    def objects(self, tmpdir):
         cp = configparser.ConfigParser(interpolation=None,
                                        comment_prefixes='#')
         cp.optionxform = lambda opt: opt  # be case-insensitive
         cfg = config.ConfigManager()
-        cfg.read(None, None)
+        cfg.read(str(tmpdir), 'qutebrowser.conf')
         return self.Objects(cp=cp, cfg=cfg)
 
     @pytest.mark.parametrize('config, section, option, value', [
@@ -247,7 +244,7 @@ class TestKeyConfigParser:
 
     """Test config.parsers.keyconf.KeyConfigParser."""
 
-    def test_cmd_binding(self, cmdline_test, config_stub):
+    def test_cmd_binding(self, cmdline_test, config_stub, tmpdir):
         """Test various command bindings.
 
         See https://github.com/The-Compiler/qutebrowser/issues/615
@@ -256,7 +253,7 @@ class TestKeyConfigParser:
             cmdline_test: A pytest fixture which provides testcases.
         """
         config_stub.data = {'aliases': []}
-        kcp = keyconf.KeyConfigParser(None, None)
+        kcp = keyconf.KeyConfigParser(str(tmpdir), 'keys.conf')
         kcp._cur_section = 'normal'
         if cmdline_test.valid:
             kcp._read_command(cmdline_test.cmd)
@@ -379,17 +376,17 @@ class TestDefaultConfig:
     """Test validating of the default config."""
 
     @pytest.mark.usefixtures('qapp')
-    def test_default_config(self):
+    def test_default_config(self, tmpdir):
         """Test validating of the default config."""
         conf = config.ConfigManager()
-        conf.read(None, None)
+        conf.read(str(tmpdir), 'qutebrowser.conf')
         conf._validate_all()
 
-    def test_default_key_config(self):
+    def test_default_key_config(self, tmpdir):
         """Test validating of the default key config."""
         # We import qutebrowser.app so the cmdutils.register decorators run.
         import qutebrowser.app  # pylint: disable=unused-variable
-        conf = keyconf.KeyConfigParser(None, None)
+        conf = keyconf.KeyConfigParser(str(tmpdir), 'keys.conf')
         runner = runners.CommandRunner(win_id=0)
         for sectname in configdata.KEY_DATA:
             for cmd in conf.get_bindings_for(sectname).values():
@@ -418,48 +415,3 @@ class TestDefaultConfig:
         shutil.copy(full_path, str(tmpdir / 'qutebrowser.conf'))
         conf = config.ConfigManager()
         conf.read(str(tmpdir), 'qutebrowser.conf')
-
-
-@pytest.mark.integration
-class TestConfigInit:
-
-    """Test initializing of the config."""
-
-    @pytest.fixture(autouse=True)
-    def patch(self, fake_args):
-        objreg.register('app', QObject())
-        objreg.register('save-manager', mock.MagicMock())
-        fake_args.relaxed_config = False
-        old_standarddir_args = standarddir._args
-        yield
-        objreg.delete('app')
-        objreg.delete('save-manager')
-        # registered by config.init()
-        objreg.delete('config')
-        objreg.delete('key-config')
-        objreg.delete('state-config')
-        standarddir._args = old_standarddir_args
-
-    @pytest.fixture
-    def env(self, tmpdir):
-        conf_path = (tmpdir / 'config').ensure(dir=1)
-        data_path = (tmpdir / 'data').ensure(dir=1)
-        cache_path = (tmpdir / 'cache').ensure(dir=1)
-        env = {
-            'XDG_CONFIG_HOME': str(conf_path),
-            'XDG_DATA_HOME': str(data_path),
-            'XDG_CACHE_HOME': str(cache_path),
-        }
-        return env
-
-    def test_config_none(self, monkeypatch, env, fake_args):
-        """Test initializing with config path set to None."""
-        fake_args.confdir = ''
-        fake_args.datadir = ''
-        fake_args.cachedir = ''
-        fake_args.basedir = None
-        for k, v in env.items():
-            monkeypatch.setenv(k, v)
-        standarddir.init(fake_args)
-        config.init()
-        assert not os.listdir(env['XDG_CONFIG_HOME'])
diff --git a/tests/unit/config/test_configtypes.py b/tests/unit/config/test_configtypes.py
index 3a87ac999..2133cedd0 100644
--- a/tests/unit/config/test_configtypes.py
+++ b/tests/unit/config/test_configtypes.py
@@ -1284,14 +1284,6 @@ class TestFileAndUserStyleSheet:
         os_mock.path.join.assert_called_once_with(
             '/home/foo/.config/', 'foobar')
 
-    def test_validate_rel_config_none_file(self, os_mock, monkeypatch):
-        """Test with a relative path and standarddir.config returning None."""
-        monkeypatch.setattr(
-            'qutebrowser.config.configtypes.standarddir.config', lambda: None)
-        os_mock.path.isabs.return_value = False
-        with pytest.raises(configexc.ValidationError):
-            configtypes.File().validate('foobar')
-
     @pytest.mark.parametrize('configtype, value, raises', [
         (configtypes.File(), 'foobar', True),
         (configtypes.UserStyleSheet(), 'foobar', False),
@@ -1355,14 +1347,8 @@ class TestFileAndUserStyleSheet:
         expected = self._expected(klass, '/configdir/foo')
         assert klass().transform('foo') == expected
 
-    @pytest.mark.parametrize('no_config', [False, True])
-    def test_transform_userstylesheet_base64(self, monkeypatch, no_config):
+    def test_transform_userstylesheet_base64(self, monkeypatch):
         """Test transform with a data string."""
-        if no_config:
-            monkeypatch.setattr(
-                'qutebrowser.config.configtypes.standarddir.config',
-                lambda: None)
-
         b64 = base64.b64encode(b"test").decode('ascii')
         url = QUrl("data:text/css;charset=utf-8;base64,{}".format(b64))
         assert configtypes.UserStyleSheet().transform("test") == url
diff --git a/tests/unit/misc/test_lineparser.py b/tests/unit/misc/test_lineparser.py
index f5fbb2f4d..546d53cf9 100644
--- a/tests/unit/misc/test_lineparser.py
+++ b/tests/unit/misc/test_lineparser.py
@@ -52,15 +52,6 @@ class TestBaseLineParser:
         lineparser._prepare_save()
         os_mock.makedirs.assert_called_with(self.CONFDIR, 0o755)
 
-    def test_prepare_save_no_config(self, mocker):
-        """Test if _prepare_save doesn't create a None config dir."""
-        os_mock = mocker.patch('qutebrowser.misc.lineparser.os')
-        os_mock.path.exists.return_value = True
-
-        lineparser = lineparsermod.BaseLineParser(None, self.FILENAME)
-        assert not lineparser._prepare_save()
-        assert not os_mock.makedirs.called
-
     def test_double_open(self, mocker, lineparser):
         """Test if _open refuses reentry."""
         mocker.patch('builtins.open', mock.mock_open())
@@ -158,15 +149,6 @@ class TestAppendLineParser:
         lineparser.save()
         assert (tmpdir / 'file').read() == self._get_expected(new_data)
 
-    def test_save_without_configdir(self, tmpdir, lineparser):
-        """Test save() failing because no configdir was set."""
-        new_data = ['new data 1', 'new data 2']
-        lineparser.new_data = new_data
-        lineparser._configdir = None
-        assert not lineparser.save()
-        # make sure new data is still there
-        assert lineparser.new_data == new_data
-
     def test_clear(self, tmpdir, lineparser):
         """Check if calling clear() empties both pending and persisted data."""
         lineparser.new_data = ['one', 'two']
@@ -179,14 +161,6 @@ class TestAppendLineParser:
         assert not lineparser.new_data
         assert (tmpdir / 'file').read() == ""
 
-    def test_clear_without_configdir(self, tmpdir, lineparser):
-        """Test clear() failing because no configdir was set."""
-        new_data = ['new data 1', 'new data 2']
-        lineparser.new_data = new_data
-        lineparser._configdir = None
-        assert not lineparser.clear()
-        assert lineparser.new_data == new_data
-
     def test_iter_without_open(self, lineparser):
         """Test __iter__ without having called open()."""
         with pytest.raises(ValueError):
diff --git a/tests/unit/misc/test_sessions.py b/tests/unit/misc/test_sessions.py
index 557ed7b2f..f1810c203 100644
--- a/tests/unit/misc/test_sessions.py
+++ b/tests/unit/misc/test_sessions.py
@@ -40,9 +40,9 @@ webengine_refactoring_xfail = pytest.mark.xfail(
 
 
 @pytest.fixture
-def sess_man():
-    """Fixture providing a SessionManager with no session dir."""
-    return sessions.SessionManager(base_path=None)
+def sess_man(tmpdir):
+    """Fixture providing a SessionManager."""
+    return sessions.SessionManager(base_path=str(tmpdir))
 
 
 class TestInit:
@@ -52,13 +52,6 @@ class TestInit:
         yield
         objreg.delete('session-manager')
 
-    def test_no_standarddir(self, monkeypatch):
-        monkeypatch.setattr('qutebrowser.misc.sessions.standarddir.data',
-                            lambda: None)
-        sessions.init()
-        manager = objreg.get('session-manager')
-        assert manager._base_path is None
-
     @pytest.mark.parametrize('create_dir', [True, False])
     def test_with_standarddir(self, tmpdir, monkeypatch, create_dir):
         monkeypatch.setattr('qutebrowser.misc.sessions.standarddir.data',
@@ -110,16 +103,6 @@ class TestExists:
 
         assert not man.exists(name)
 
-    @pytest.mark.parametrize('absolute', [True, False])
-    def test_no_datadir(self, sess_man, tmpdir, absolute):
-        abs_session = tmpdir / 'foo.yml'
-        abs_session.ensure()
-
-        if absolute:
-            assert sess_man.exists(str(abs_session))
-        else:
-            assert not sess_man.exists('foo')
-
 
 @webengine_refactoring_xfail
 class TestSaveTab:
@@ -247,11 +230,6 @@ class TestSave:
         objreg.delete('main-window', scope='window', window=0)
         objreg.delete('tabbed-browser', scope='window', window=0)
 
-    def test_no_config_storage(self, sess_man):
-        with pytest.raises(sessions.SessionError) as excinfo:
-            sess_man.save('foo')
-        assert str(excinfo.value) == "No data storage configured."
-
     def test_update_completion_signal(self, sess_man, tmpdir, qtbot):
         session_path = tmpdir / 'foo.yml'
         with qtbot.waitSignal(sess_man.update_completion):
@@ -415,9 +393,6 @@ def test_delete_update_completion_signal(sess_man, qtbot, tmpdir):
 
 class TestListSessions:
 
-    def test_no_base_path(self, sess_man):
-        assert not sess_man.list_sessions()
-
     def test_no_sessions(self, tmpdir):
         sess_man = sessions.SessionManager(str(tmpdir))
         assert not sess_man.list_sessions()
diff --git a/tests/unit/utils/test_standarddir.py b/tests/unit/utils/test_standarddir.py
index a40adb748..96a121b3f 100644
--- a/tests/unit/utils/test_standarddir.py
+++ b/tests/unit/utils/test_standarddir.py
@@ -165,15 +165,12 @@ class TestArguments:
 
     """Tests with confdir/cachedir/datadir arguments."""
 
-    @pytest.fixture(params=[DirArgTest('', None), DirArgTest('foo', 'foo')])
+    @pytest.fixture(params=[DirArgTest('foo', 'foo')])
     def testcase(self, request, tmpdir):
         """Fixture providing testcases."""
-        if request.param.expected is None:
-            return request.param
-        else:
-            # prepend tmpdir to both
-            arg = str(tmpdir / request.param.arg)
-            return DirArgTest(arg, arg)
+        # prepend tmpdir to both
+        arg = str(tmpdir / request.param.arg)
+        return DirArgTest(arg, arg)
 
     def test_confdir(self, testcase):
         """Test --confdir."""
@@ -210,8 +207,8 @@ class TestArguments:
         monkeypatch.setattr(
             'qutebrowser.utils.standarddir.QStandardPaths.writableLocation',
             lambda _typ: str(tmpdir))
-        args = types.SimpleNamespace(confdir=None, cachedir=None, datadir=None,
-                                     basedir=None)
+        args = types.SimpleNamespace(confdir=None, cachedir=None,
+                                     datadir=None, basedir=None)
         standarddir.init(args)
         assert standarddir.runtime() == str(tmpdir / 'qute_test')
 
@@ -239,13 +236,6 @@ class TestInitCacheDirTag:
 
     """Tests for _init_cachedir_tag."""
 
-    def test_no_cache_dir(self, mocker, monkeypatch):
-        """Smoke test with cache() returning None."""
-        monkeypatch.setattr('qutebrowser.utils.standarddir.cache',
-                            lambda: None)
-        mocker.patch('builtins.open', side_effect=AssertionError)
-        standarddir._init_cachedir_tag()
-
     def test_existent_cache_dir_tag(self, tmpdir, mocker, monkeypatch):
         """Test with an existent CACHEDIR.TAG."""
         monkeypatch.setattr('qutebrowser.utils.standarddir.cache',