Merge pull request #7772 from pylbrecht/logfilter

Don't crash on --logfilter at startup 

12 files changed, 369 insertions, 278 deletions

diff --git a/qutebrowser/browser/network/pac.py b/qutebrowser/browser/network/pac.py
index 54c1195af..162e1c5d0 100644
--- a/qutebrowser/browser/network/pac.py
+++ b/qutebrowser/browser/network/pac.py
@@ -28,7 +28,7 @@ from qutebrowser.qt.network import (QNetworkProxy, QNetworkRequest, QHostInfo,
                              QHostAddress)
 from qutebrowser.qt.qml import QJSEngine, QJSValue
 
-from qutebrowser.utils import log, utils, qtutils, resources, urlutils
+from qutebrowser.utils import log, qtlog, utils, qtutils, resources, urlutils
 
 
 class ParseProxyError(Exception):
@@ -258,7 +258,7 @@ class PACFetcher(QObject):
         url.setScheme(url.scheme()[len(pac_prefix):])
 
         self._pac_url = url
-        with log.disable_qt_msghandler():
+        with qtlog.disable_qt_msghandler():
             # WORKAROUND for a hang when messages are printed, see our
             # NetworkAccessManager subclass for details.
             self._manager: Optional[QNetworkAccessManager] = QNetworkAccessManager()
diff --git a/qutebrowser/browser/qtnetworkdownloads.py b/qutebrowser/browser/qtnetworkdownloads.py
index cd4a75351..0b20b3785 100644
--- a/qutebrowser/browser/qtnetworkdownloads.py
+++ b/qutebrowser/browser/qtnetworkdownloads.py
@@ -29,7 +29,7 @@ from qutebrowser.qt.widgets import QApplication
 from qutebrowser.qt.network import QNetworkRequest, QNetworkReply, QNetworkAccessManager
 
 from qutebrowser.config import config, websettings
-from qutebrowser.utils import message, usertypes, log, urlutils, utils, debug, objreg
+from qutebrowser.utils import message, usertypes, log, urlutils, utils, debug, objreg, qtlog
 from qutebrowser.misc import quitter
 from qutebrowser.browser import downloads
 from qutebrowser.browser.webkit import http
@@ -121,7 +121,7 @@ class DownloadItem(downloads.AbstractDownloadItem):
         self._reply.errorOccurred.disconnect()
         self._reply.readyRead.disconnect()
 
-        with log.hide_qt_warning('QNetworkReplyImplPrivate::error: Internal '
+        with qtlog.hide_qt_warning('QNetworkReplyImplPrivate::error: Internal '
                                  'problem, this method must only be called '
                                  'once.'):
             # See https://codereview.qt-project.org/#/c/107863/
diff --git a/qutebrowser/browser/webkit/network/networkmanager.py b/qutebrowser/browser/webkit/network/networkmanager.py
index 91e609456..4c1c767ec 100644
--- a/qutebrowser/browser/webkit/network/networkmanager.py
+++ b/qutebrowser/browser/webkit/network/networkmanager.py
@@ -28,7 +28,7 @@ from qutebrowser.qt.network import (QNetworkAccessManager, QNetworkReply, QSslCo
 
 from qutebrowser.config import config
 from qutebrowser.utils import (message, log, usertypes, utils, objreg,
-                               urlutils, debug)
+                               urlutils, debug, qtlog)
 from qutebrowser.browser import shared
 from qutebrowser.browser.network import proxy as proxymod
 from qutebrowser.extensions import interceptors
@@ -156,7 +156,7 @@ class NetworkManager(QNetworkAccessManager):
 
     def __init__(self, *, win_id, tab_id, private, parent=None):
         log.init.debug("Initializing NetworkManager")
-        with log.disable_qt_msghandler():
+        with qtlog.disable_qt_msghandler():
             # WORKAROUND for a hang when a message is printed - See:
             # https://www.riverbankcomputing.com/pipermail/pyqt/2014-November/035045.html
             #
diff --git a/qutebrowser/misc/earlyinit.py b/qutebrowser/misc/earlyinit.py
index a0265d653..57e821784 100644
--- a/qutebrowser/misc/earlyinit.py
+++ b/qutebrowser/misc/earlyinit.py
@@ -298,7 +298,17 @@ def init_log(args):
     from qutebrowser.utils import log
     log.init_log(args)
     log.init.debug("Log initialized.")
-    log.init.debug(str(machinery.INFO))
+
+
+def init_qtlog(args):
+    """Initialize Qt logging.
+
+    Args:
+        args: The argparse namespace.
+    """
+    from qutebrowser.utils import log, qtlog
+    qtlog.init(args)
+    log.init.debug("Qt log initialized.")
 
 
 def check_optimize_flag():
@@ -333,16 +343,18 @@ def early_init(args):
     Args:
         args: The argparse namespace.
     """
+    # Init logging as early as possible
+    init_log(args)
     # First we initialize the faulthandler as early as possible, so we
     # theoretically could catch segfaults occurring later during earlyinit.
     init_faulthandler()
     # Then we configure the selected Qt wrapper
     info = machinery.init(args)
+    # Init Qt logging after machinery is initialized
+    init_qtlog(args)
     # Here we check if QtCore is available, and if not, print a message to the
     # console or via Tk.
     check_qt_available(info)
-    # Init logging as early as possible
-    init_log(args)
     # Now we can be sure QtCore is available, so we can print dialogs on
     # errors, so people only using the GUI notice them as well.
     check_libraries()
diff --git a/qutebrowser/misc/httpclient.py b/qutebrowser/misc/httpclient.py
index 2bb152b03..45d491996 100644
--- a/qutebrowser/misc/httpclient.py
+++ b/qutebrowser/misc/httpclient.py
@@ -25,7 +25,7 @@ from qutebrowser.qt.core import pyqtSignal, QObject, QTimer
 from qutebrowser.qt.network import (QNetworkAccessManager, QNetworkRequest,
                              QNetworkReply)
 
-from qutebrowser.utils import log
+from qutebrowser.utils import qtlog
 
 
 class HTTPRequest(QNetworkRequest):
@@ -59,7 +59,7 @@ class HTTPClient(QObject):
 
     def __init__(self, parent=None):
         super().__init__(parent)
-        with log.disable_qt_msghandler():
+        with qtlog.disable_qt_msghandler():
             # WORKAROUND for a hang when messages are printed, see our
             # NetworkAccessManager subclass for details.
             self._nam = QNetworkAccessManager(self)
diff --git a/qutebrowser/misc/quitter.py b/qutebrowser/misc/quitter.py
index d502efa65..59e2d552f 100644
--- a/qutebrowser/misc/quitter.py
+++ b/qutebrowser/misc/quitter.py
@@ -37,7 +37,7 @@ except ImportError:
 
 import qutebrowser
 from qutebrowser.api import cmdutils
-from qutebrowser.utils import log
+from qutebrowser.utils import log, qtlog
 from qutebrowser.misc import sessions, ipc, objects
 from qutebrowser.mainwindow import prompt
 from qutebrowser.completion.models import miscmodels
@@ -304,5 +304,5 @@ def init(args: argparse.Namespace) -> None:
     """Initialize the global Quitter instance."""
     global instance
     instance = Quitter(args=args, parent=objects.qapp)
-    instance.shutting_down.connect(log.shutdown_log)
+    instance.shutting_down.connect(qtlog.shutdown_log)
     objects.qapp.lastWindowClosed.connect(instance.on_last_window_closed)
diff --git a/qutebrowser/qt/machinery.py b/qutebrowser/qt/machinery.py
index 4e88a0634..e626edcb4 100644
--- a/qutebrowser/qt/machinery.py
+++ b/qutebrowser/qt/machinery.py
@@ -18,6 +18,8 @@ import importlib
 import dataclasses
 from typing import Optional, Dict
 
+from qutebrowser.utils import log
+
 # Packagers: Patch the line below to change the default wrapper for Qt 6 packages, e.g.:
 # sed -i 's/_DEFAULT_WRAPPER = "PyQt5"/_DEFAULT_WRAPPER = "PyQt6"/' qutebrowser/qt/machinery.py
 #
@@ -280,6 +282,7 @@ def init(args: argparse.Namespace) -> SelectionInfo:
     info = _select_wrapper(args)
     if info.wrapper is not None:
         _set_globals(info)
+        log.init.debug(str(info))
 
     # If info is None here (no Qt wrapper available), we'll show an error later
     # in earlyinit.py.
diff --git a/qutebrowser/utils/log.py b/qutebrowser/utils/log.py
index 5ac150702..f2a6c396d 100644
--- a/qutebrowser/utils/log.py
+++ b/qutebrowser/utils/log.py
@@ -24,17 +24,16 @@ import logging
 import contextlib
 import collections
 import copy
-import faulthandler
-import traceback
 import warnings
 import json
 import inspect
 import argparse
 from typing import (TYPE_CHECKING, Any, Iterator, Mapping, MutableSequence,
-                    Optional, Set, Tuple, Union, TextIO, Literal, cast, Callable)
+                    Optional, Set, Tuple, Union, TextIO, Literal, cast)
+
+# NOTE: This is a Qt-free zone! All imports related to Qt logging should be done in
+# qutebrowser.utils.qtlog (see https://github.com/qutebrowser/qutebrowser/issues/7769).
 
-from qutebrowser.qt import core as qtcore
-from qutebrowser.qt import machinery
 # Optional imports
 try:
     import colorama
@@ -209,15 +208,9 @@ def init_log(args: argparse.Namespace) -> None:
     root.setLevel(logging.NOTSET)
     logging.captureWarnings(True)
     _init_py_warnings()
-    qtcore.qInstallMessageHandler(qt_message_handler)
     _log_inited = True
 
 
-@qtcore.pyqtSlot()
-def shutdown_log() -> None:
-    qtcore.qInstallMessageHandler(None)
-
-
 def _init_py_warnings() -> None:
     """Initialize Python warning handling."""
     assert _args is not None
@@ -232,29 +225,6 @@ def _init_py_warnings() -> None:
 
 
 @contextlib.contextmanager
-def disable_qt_msghandler() -> Iterator[None]:
-    """Contextmanager which temporarily disables the Qt message handler."""
-    old_handler = qtcore.qInstallMessageHandler(None)
-    if machinery.IS_QT6:
-        # cast str to Optional[str] to be compatible with PyQt6 type hints for
-        # qInstallMessageHandler
-        old_handler = cast(
-            Optional[
-                Callable[
-                    [qtcore.QtMsgType, qtcore.QMessageLogContext, Optional[str]],
-                    None
-                ]
-            ],
-            old_handler,
-        )
-
-    try:
-        yield
-    finally:
-        qtcore.qInstallMessageHandler(old_handler)
-
-
-@contextlib.contextmanager
 def py_warning_filter(
     action:
         Literal['default', 'error', 'ignore', 'always', 'module', 'once'] = 'ignore',
@@ -391,163 +361,6 @@ def change_console_formatter(level: int) -> None:
         assert isinstance(old_formatter, JSONFormatter), old_formatter
 
 
-def qt_message_handler(msg_type: qtcore.QtMsgType,
-                       context: qtcore.QMessageLogContext,
-                       msg: Optional[str]) -> None:
-    """Qt message handler to redirect qWarning etc. to the logging system.
-
-    Args:
-        msg_type: The level of the message.
-        context: The source code location of the message.
-        msg: The message text.
-    """
-    # Mapping from Qt logging levels to the matching logging module levels.
-    # Note we map critical to ERROR as it's actually "just" an error, and fatal
-    # to critical.
-    qt_to_logging = {
-        qtcore.QtMsgType.QtDebugMsg: logging.DEBUG,
-        qtcore.QtMsgType.QtWarningMsg: logging.WARNING,
-        qtcore.QtMsgType.QtCriticalMsg: logging.ERROR,
-        qtcore.QtMsgType.QtFatalMsg: logging.CRITICAL,
-        qtcore.QtMsgType.QtInfoMsg: logging.INFO,
-    }
-
-    # Change levels of some well-known messages to debug so they don't get
-    # shown to the user.
-    #
-    # If a message starts with any text in suppressed_msgs, it's not logged as
-    # error.
-    suppressed_msgs = [
-        # PNGs in Qt with broken color profile
-        # https://bugreports.qt.io/browse/QTBUG-39788
-        ('libpng warning: iCCP: Not recognizing known sRGB profile that has '
-         'been edited'),
-        'libpng warning: iCCP: known incorrect sRGB profile',
-        # Hopefully harmless warning
-        'OpenType support missing for script ',
-        # Error if a QNetworkReply gets two different errors set. Harmless Qt
-        # bug on some pages.
-        # https://bugreports.qt.io/browse/QTBUG-30298
-        ('QNetworkReplyImplPrivate::error: Internal problem, this method must '
-         'only be called once.'),
-        # Sometimes indicates missing text, but most of the time harmless
-        'load glyph failed ',
-        # Harmless, see https://bugreports.qt.io/browse/QTBUG-42479
-        ('content-type missing in HTTP POST, defaulting to '
-         'application/x-www-form-urlencoded. '
-         'Use QNetworkRequest::setHeader() to fix this problem.'),
-        # https://bugreports.qt.io/browse/QTBUG-43118
-        'Using blocking call!',
-        # Hopefully harmless
-        ('"Method "GetAll" with signature "s" on interface '
-         '"org.freedesktop.DBus.Properties" doesn\'t exist'),
-        ('"Method \\"GetAll\\" with signature \\"s\\" on interface '
-         '\\"org.freedesktop.DBus.Properties\\" doesn\'t exist\\n"'),
-        'WOFF support requires QtWebKit to be built with zlib support.',
-        # Weird Enlightment/GTK X extensions
-        'QXcbWindow: Unhandled client message: "_E_',
-        'QXcbWindow: Unhandled client message: "_ECORE_',
-        'QXcbWindow: Unhandled client message: "_GTK_',
-        # Happens on AppVeyor CI
-        'SetProcessDpiAwareness failed:',
-        # https://bugreports.qt.io/browse/QTBUG-49174
-        ('QObject::connect: Cannot connect (null)::stateChanged('
-         'QNetworkSession::State) to '
-         'QNetworkReplyHttpImpl::_q_networkSessionStateChanged('
-         'QNetworkSession::State)'),
-        # https://bugreports.qt.io/browse/QTBUG-53989
-        ("Image of format '' blocked because it is not considered safe. If "
-         "you are sure it is safe to do so, you can white-list the format by "
-         "setting the environment variable QTWEBKIT_IMAGEFORMAT_WHITELIST="),
-        # Installing Qt from the installer may cause it looking for SSL3 or
-        # OpenSSL 1.0 which may not be available on the system
-        "QSslSocket: cannot resolve ",
-        "QSslSocket: cannot call unresolved function ",
-        # When enabling debugging with QtWebEngine
-        ("Remote debugging server started successfully. Try pointing a "
-         "Chromium-based browser to "),
-        # https://github.com/qutebrowser/qutebrowser/issues/1287
-        "QXcbClipboard: SelectionRequest too old",
-        # https://github.com/qutebrowser/qutebrowser/issues/2071
-        'QXcbWindow: Unhandled client message: ""',
-        # https://codereview.qt-project.org/176831
-        "QObject::disconnect: Unexpected null parameter",
-        # https://bugreports.qt.io/browse/QTBUG-76391
-        "Attribute Qt::AA_ShareOpenGLContexts must be set before "
-        "QCoreApplication is created.",
-        # Qt 6.4 beta 1: https://bugreports.qt.io/browse/QTBUG-104741
-        "GL format 0 is not supported",
-    ]
-    # not using utils.is_mac here, because we can't be sure we can successfully
-    # import the utils module here.
-    if sys.platform == 'darwin':
-        suppressed_msgs += [
-            # https://bugreports.qt.io/browse/QTBUG-47154
-            ('virtual void QSslSocketBackendPrivate::transmit() SSLRead '
-             'failed with: -9805'),
-        ]
-
-    if not msg:
-        msg = "Logged empty message!"
-
-    if any(msg.strip().startswith(pattern) for pattern in suppressed_msgs):
-        level = logging.DEBUG
-    elif context.category == "qt.webenginecontext" and (
-        msg.strip().startswith("GL Type: ") or  # Qt 6.3
-        msg.strip().startswith("GLImplementation:")  # Qt 6.2
-    ):
-        level = logging.DEBUG
-    else:
-        level = qt_to_logging[msg_type]
-
-    if context.line is None:
-        lineno = -1  # type: ignore[unreachable]
-    else:
-        lineno = context.line
-
-    if context.function is None:
-        func = 'none'  # type: ignore[unreachable]
-    elif ':' in context.function:
-        func = '"{}"'.format(context.function)
-    else:
-        func = context.function
-
-    if context.category is None or context.category == 'default':
-        name = 'qt'
-    else:
-        name = 'qt-' + context.category
-    if msg.splitlines()[0] == ('This application failed to start because it '
-                               'could not find or load the Qt platform plugin '
-                               '"xcb".'):
-        # Handle this message specially.
-        msg += ("\n\nOn Archlinux, this should fix the problem:\n"
-                "    pacman -S libxkbcommon-x11")
-        faulthandler.disable()
-
-    assert _args is not None
-    if _args.debug:
-        stack: Optional[str] = ''.join(traceback.format_stack())
-    else:
-        stack = None
-
-    record = qt.makeRecord(name=name, level=level, fn=context.file, lno=lineno,
-                           msg=msg, args=(), exc_info=None, func=func,
-                           sinfo=stack)
-    qt.handle(record)
-
-
-@contextlib.contextmanager
-def hide_qt_warning(pattern: str, logger: str = 'qt') -> Iterator[None]:
-    """Hide Qt warnings matching the given regex."""
-    log_filter = QtWarningFilter(pattern)
-    logger_obj = logging.getLogger(logger)
-    logger_obj.addFilter(log_filter)
-    try:
-        yield
-    finally:
-        logger_obj.removeFilter(log_filter)
-
-
 def init_from_config(conf: 'configmodule.ConfigContainer') -> None:
     """Initialize logging settings from the config.
 
@@ -578,24 +391,6 @@ def init_from_config(conf: 'configmodule.ConfigContainer') -> None:
             change_console_formatter(level)
 
 
-class QtWarningFilter(logging.Filter):
-
-    """Filter to filter Qt warnings.
-
-    Attributes:
-        _pattern: The start of the message.
-    """
-
-    def __init__(self, pattern: str) -> None:
-        super().__init__()
-        self._pattern = pattern
-
-    def filter(self, record: logging.LogRecord) -> bool:
-        """Determine if the specified record is to be logged."""
-        do_log = not record.msg.strip().startswith(self._pattern)
-        return do_log
-
-
 class InvalidLogFilterError(Exception):
 
     """Raised when an invalid filter string is passed to LogFilter.parse()."""
diff --git a/qutebrowser/utils/qtlog.py b/qutebrowser/utils/qtlog.py
new file mode 100644
index 000000000..15e124b79
--- /dev/null
+++ b/qutebrowser/utils/qtlog.py
@@ -0,0 +1,241 @@
+# Copyright 2014-2023 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
+
+"""Loggers and utilities related to Qt logging."""
+
+import argparse
+import contextlib
+import faulthandler
+import logging
+import sys
+import traceback
+from typing import Iterator, Optional, Callable, cast
+
+from qutebrowser.qt import core as qtcore, machinery
+from qutebrowser.utils import log
+
+_args = None
+
+
+def init(args: argparse.Namespace) -> None:
+    """Install Qt message handler based on the argparse namespace passed."""
+    global _args
+    _args = args
+    qtcore.qInstallMessageHandler(qt_message_handler)
+
+
+@qtcore.pyqtSlot()
+def shutdown_log() -> None:
+    qtcore.qInstallMessageHandler(None)
+
+
+@contextlib.contextmanager
+def disable_qt_msghandler() -> Iterator[None]:
+    """Contextmanager which temporarily disables the Qt message handler."""
+    old_handler = qtcore.qInstallMessageHandler(None)
+    if machinery.IS_QT6:
+        # cast str to Optional[str] to be compatible with PyQt6 type hints for
+        # qInstallMessageHandler
+        old_handler = cast(
+            Optional[
+                Callable[
+                    [qtcore.QtMsgType, qtcore.QMessageLogContext, Optional[str]],
+                    None
+                ]
+            ],
+            old_handler,
+        )
+
+    try:
+        yield
+    finally:
+        qtcore.qInstallMessageHandler(old_handler)
+
+
+def qt_message_handler(msg_type: qtcore.QtMsgType,
+                       context: qtcore.QMessageLogContext,
+                       msg: Optional[str]) -> None:
+    """Qt message handler to redirect qWarning etc. to the logging system.
+
+    Args:
+        msg_type: The level of the message.
+        context: The source code location of the message.
+        msg: The message text.
+    """
+    # Mapping from Qt logging levels to the matching logging module levels.
+    # Note we map critical to ERROR as it's actually "just" an error, and fatal
+    # to critical.
+    qt_to_logging = {
+        qtcore.QtMsgType.QtDebugMsg: logging.DEBUG,
+        qtcore.QtMsgType.QtWarningMsg: logging.WARNING,
+        qtcore.QtMsgType.QtCriticalMsg: logging.ERROR,
+        qtcore.QtMsgType.QtFatalMsg: logging.CRITICAL,
+        qtcore.QtMsgType.QtInfoMsg: logging.INFO,
+    }
+
+    # Change levels of some well-known messages to debug so they don't get
+    # shown to the user.
+    #
+    # If a message starts with any text in suppressed_msgs, it's not logged as
+    # error.
+    suppressed_msgs = [
+        # PNGs in Qt with broken color profile
+        # https://bugreports.qt.io/browse/QTBUG-39788
+        ('libpng warning: iCCP: Not recognizing known sRGB profile that has '
+         'been edited'),
+        'libpng warning: iCCP: known incorrect sRGB profile',
+        # Hopefully harmless warning
+        'OpenType support missing for script ',
+        # Error if a QNetworkReply gets two different errors set. Harmless Qt
+        # bug on some pages.
+        # https://bugreports.qt.io/browse/QTBUG-30298
+        ('QNetworkReplyImplPrivate::error: Internal problem, this method must '
+         'only be called once.'),
+        # Sometimes indicates missing text, but most of the time harmless
+        'load glyph failed ',
+        # Harmless, see https://bugreports.qt.io/browse/QTBUG-42479
+        ('content-type missing in HTTP POST, defaulting to '
+         'application/x-www-form-urlencoded. '
+         'Use QNetworkRequest::setHeader() to fix this problem.'),
+        # https://bugreports.qt.io/browse/QTBUG-43118
+        'Using blocking call!',
+        # Hopefully harmless
+        ('"Method "GetAll" with signature "s" on interface '
+         '"org.freedesktop.DBus.Properties" doesn\'t exist'),
+        ('"Method \\"GetAll\\" with signature \\"s\\" on interface '
+         '\\"org.freedesktop.DBus.Properties\\" doesn\'t exist\\n"'),
+        'WOFF support requires QtWebKit to be built with zlib support.',
+        # Weird Enlightment/GTK X extensions
+        'QXcbWindow: Unhandled client message: "_E_',
+        'QXcbWindow: Unhandled client message: "_ECORE_',
+        'QXcbWindow: Unhandled client message: "_GTK_',
+        # Happens on AppVeyor CI
+        'SetProcessDpiAwareness failed:',
+        # https://bugreports.qt.io/browse/QTBUG-49174
+        ('QObject::connect: Cannot connect (null)::stateChanged('
+         'QNetworkSession::State) to '
+         'QNetworkReplyHttpImpl::_q_networkSessionStateChanged('
+         'QNetworkSession::State)'),
+        # https://bugreports.qt.io/browse/QTBUG-53989
+        ("Image of format '' blocked because it is not considered safe. If "
+         "you are sure it is safe to do so, you can white-list the format by "
+         "setting the environment variable QTWEBKIT_IMAGEFORMAT_WHITELIST="),
+        # Installing Qt from the installer may cause it looking for SSL3 or
+        # OpenSSL 1.0 which may not be available on the system
+        "QSslSocket: cannot resolve ",
+        "QSslSocket: cannot call unresolved function ",
+        # When enabling debugging with QtWebEngine
+        ("Remote debugging server started successfully. Try pointing a "
+         "Chromium-based browser to "),
+        # https://github.com/qutebrowser/qutebrowser/issues/1287
+        "QXcbClipboard: SelectionRequest too old",
+        # https://github.com/qutebrowser/qutebrowser/issues/2071
+        'QXcbWindow: Unhandled client message: ""',
+        # https://codereview.qt-project.org/176831
+        "QObject::disconnect: Unexpected null parameter",
+        # https://bugreports.qt.io/browse/QTBUG-76391
+        "Attribute Qt::AA_ShareOpenGLContexts must be set before "
+        "QCoreApplication is created.",
+        # Qt 6.4 beta 1: https://bugreports.qt.io/browse/QTBUG-104741
+        "GL format 0 is not supported",
+    ]
+    # not using utils.is_mac here, because we can't be sure we can successfully
+    # import the utils module here.
+    if sys.platform == 'darwin':
+        suppressed_msgs += [
+            # https://bugreports.qt.io/browse/QTBUG-47154
+            ('virtual void QSslSocketBackendPrivate::transmit() SSLRead '
+             'failed with: -9805'),
+        ]
+
+    if not msg:
+        msg = "Logged empty message!"
+
+    if any(msg.strip().startswith(pattern) for pattern in suppressed_msgs):
+        level = logging.DEBUG
+    elif context.category == "qt.webenginecontext" and (
+        msg.strip().startswith("GL Type: ") or  # Qt 6.3
+        msg.strip().startswith("GLImplementation:")  # Qt 6.2
+    ):
+        level = logging.DEBUG
+    else:
+        level = qt_to_logging[msg_type]
+
+    if context.line is None:
+        lineno = -1  # type: ignore[unreachable]
+    else:
+        lineno = context.line
+
+    if context.function is None:
+        func = 'none'  # type: ignore[unreachable]
+    elif ':' in context.function:
+        func = '"{}"'.format(context.function)
+    else:
+        func = context.function
+
+    if context.category is None or context.category == 'default':
+        name = 'qt'
+    else:
+        name = 'qt-' + context.category
+    if msg.splitlines()[0] == ('This application failed to start because it '
+                               'could not find or load the Qt platform plugin '
+                               '"xcb".'):
+        # Handle this message specially.
+        msg += ("\n\nOn Archlinux, this should fix the problem:\n"
+                "    pacman -S libxkbcommon-x11")
+        faulthandler.disable()
+
+    assert _args is not None
+    if _args.debug:
+        stack: Optional[str] = ''.join(traceback.format_stack())
+    else:
+        stack = None
+
+    record = log.qt.makeRecord(name=name, level=level, fn=context.file, lno=lineno,
+                           msg=msg, args=(), exc_info=None, func=func,
+                           sinfo=stack)
+    log.qt.handle(record)
+
+
+class QtWarningFilter(logging.Filter):
+
+    """Filter to filter Qt warnings.
+
+    Attributes:
+        _pattern: The start of the message.
+    """
+
+    def __init__(self, pattern: str) -> None:
+        super().__init__()
+        self._pattern = pattern
+
+    def filter(self, record: logging.LogRecord) -> bool:
+        """Determine if the specified record is to be logged."""
+        do_log = not record.msg.strip().startswith(self._pattern)
+        return do_log
+
+
+@contextlib.contextmanager
+def hide_qt_warning(pattern: str, logger: str = 'qt') -> Iterator[None]:
+    """Hide Qt warnings matching the given regex."""
+    log_filter = QtWarningFilter(pattern)
+    logger_obj = logging.getLogger(logger)
+    logger_obj.addFilter(log_filter)
+    try:
+        yield
+    finally:
+        logger_obj.removeFilter(log_filter)
diff --git a/tests/end2end/test_invocations.py b/tests/end2end/test_invocations.py
index 56524a031..caa86dfbb 100644
--- a/tests/end2end/test_invocations.py
+++ b/tests/end2end/test_invocations.py
@@ -25,6 +25,7 @@ import importlib
 import re
 import json
 import platform
+from contextlib import nullcontext as does_not_raise
 
 import pytest
 from qutebrowser.qt.core import QProcess, QPoint
@@ -916,3 +917,15 @@ def test_sandboxing(
 
     status = dict(line.split("\t") for line in lines)
     assert status == expected_status
+
+
+@pytest.mark.not_frozen
+def test_logfilter_arg_does_not_crash(request, quteproc_new):
+    args = ['--temp-basedir', '--debug', '--logfilter', 'commands, init, ipc, webview']
+
+    with does_not_raise():
+        quteproc_new.start(args=args + _base_args(request.config))
+
+    # Waiting for quit to make sure no other warning is emitted
+    quteproc_new.send_cmd(':quit')
+    quteproc_new.wait_for_quit()
diff --git a/tests/unit/utils/test_log.py b/tests/unit/utils/test_log.py
index 51b014f81..6eb1c4e4f 100644
--- a/tests/unit/utils/test_log.py
+++ b/tests/unit/utils/test_log.py
@@ -22,11 +22,9 @@ import argparse
 import itertools
 import sys
 import warnings
-import dataclasses
 
 import pytest
 import _pytest.logging  # pylint: disable=import-private-name
-from qutebrowser.qt import core as qtcore
 
 from qutebrowser import qutebrowser
 from qutebrowser.utils import log
@@ -241,7 +239,7 @@ class TestInitLog:
 
     @pytest.fixture(autouse=True)
     def setup(self, mocker):
-        mocker.patch('qutebrowser.utils.log.qtcore.qInstallMessageHandler',
+        mocker.patch('qutebrowser.utils.qtlog.qtcore.qInstallMessageHandler',
                      autospec=True)
         yield
         # Make sure logging is in a sensible default state
@@ -342,35 +340,6 @@ class TestInitLog:
         assert log.console_filter.names == {'misc'}
 
 
-class TestHideQtWarning:
-
-    """Tests for hide_qt_warning/QtWarningFilter."""
-
-    @pytest.fixture
-    def qt_logger(self):
-        return logging.getLogger('qt-tests')
-
-    def test_unfiltered(self, qt_logger, caplog):
-        with log.hide_qt_warning("World", 'qt-tests'):
-            with caplog.at_level(logging.WARNING, 'qt-tests'):
-                qt_logger.warning("Hello World")
-        assert len(caplog.records) == 1
-        record = caplog.records[0]
-        assert record.levelname == 'WARNING'
-        assert record.message == "Hello World"
-
-    @pytest.mark.parametrize('line', [
-        "Hello",  # exact match
-        "Hello World",  # match at start of line
-        "  Hello World  ",  # match with spaces
-    ])
-    def test_filtered(self, qt_logger, caplog, line):
-        with log.hide_qt_warning("Hello", 'qt-tests'):
-            with caplog.at_level(logging.WARNING, 'qt-tests'):
-                qt_logger.warning(line)
-        assert not caplog.records
-
-
 @pytest.mark.parametrize('suffix, expected', [
     ('', 'STUB: test_stub'),
     ('foo', 'STUB: test_stub (foo)'),
@@ -405,27 +374,3 @@ def test_warning_still_errors():
     # Mainly a sanity check after the tests messing with warnings above.
     with pytest.raises(UserWarning):
         warnings.warn("error", UserWarning)
-
-
-class TestQtMessageHandler:
-
-    @dataclasses.dataclass
-    class Context:
-
-        """Fake QMessageLogContext."""
-
-        function: str = None
-        category: str = None
-        file: str = None
-        line: int = None
-
-    @pytest.fixture(autouse=True)
-    def init_args(self):
-        parser = qutebrowser.get_argparser()
-        args = parser.parse_args([])
-        log.init_log(args)
-
-    def test_empty_message(self, caplog):
-        """Make sure there's no crash with an empty message."""
-        log.qt_message_handler(qtcore.QtMsgType.QtDebugMsg, self.Context(), "")
-        assert caplog.messages == ["Logged empty message!"]
diff --git a/tests/unit/utils/test_qtlog.py b/tests/unit/utils/test_qtlog.py
new file mode 100644
index 000000000..3dd62b9a9
--- /dev/null
+++ b/tests/unit/utils/test_qtlog.py
@@ -0,0 +1,82 @@
+# Copyright 2014-2021 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <https://www.gnu.org/licenses/>.
+
+
+"""Tests for qutebrowser.utils.qtlog."""
+
+import dataclasses
+import logging
+
+import pytest
+
+from qutebrowser import qutebrowser
+from qutebrowser.utils import qtlog
+
+from qutebrowser.qt import core as qtcore
+
+
+class TestQtMessageHandler:
+
+    @dataclasses.dataclass
+    class Context:
+
+        """Fake QMessageLogContext."""
+
+        function: str = None
+        category: str = None
+        file: str = None
+        line: int = None
+
+    @pytest.fixture(autouse=True)
+    def init_args(self):
+        parser = qutebrowser.get_argparser()
+        args = parser.parse_args([])
+        qtlog.init(args)
+
+    def test_empty_message(self, caplog):
+        """Make sure there's no crash with an empty message."""
+        qtlog.qt_message_handler(qtcore.QtMsgType.QtDebugMsg, self.Context(), "")
+        assert caplog.messages == ["Logged empty message!"]
+
+
+class TestHideQtWarning:
+
+    """Tests for hide_qt_warning/QtWarningFilter."""
+
+    @pytest.fixture
+    def qt_logger(self):
+        return logging.getLogger('qt-tests')
+
+    def test_unfiltered(self, qt_logger, caplog):
+        with qtlog.hide_qt_warning("World", 'qt-tests'):
+            with caplog.at_level(logging.WARNING, 'qt-tests'):
+                qt_logger.warning("Hello World")
+        assert len(caplog.records) == 1
+        record = caplog.records[0]
+        assert record.levelname == 'WARNING'
+        assert record.message == "Hello World"
+
+    @pytest.mark.parametrize('line', [
+        "Hello",  # exact match
+        "Hello World",  # match at start of line
+        "  Hello World  ",  # match with spaces
+    ])
+    def test_filtered(self, qt_logger, caplog, line):
+        with qtlog.hide_qt_warning("Hello", 'qt-tests'):
+            with caplog.at_level(logging.WARNING, 'qt-tests'):
+                qt_logger.warning(line)
+        assert not caplog.records