run pakjoy for real at application boot

It all just works!

Changes from the `__main__` implementation down below:

* copy the whole resources directory instead of just the one file:
  looking at the implementation around QTWEBENGINE_RESOURCES_PATH it
  uses the main resources file to find the one directory and then loads
  the other resources from that dir. So I'm assuming it was crashing
  because it couldn't find the other resources. Stack trace was:

    #1  0x00007fffe95f1dca in content::ContentMainRunnerImpl::Initialize(content::ContentMainParams) ()
       from /usr/local/Qt-6.6.0/lib/libQt6WebEngineCore.so.6
    #2  0x00007fffe628cf09 in QtWebEngineCore::WebEngineContext::WebEngineContext() ()
       from /usr/local/Qt-6.6.0/lib/libQt6WebEngineCore.so.6
    #3  0x00007fffe628dfa4 in QtWebEngineCore::WebEngineContext::current() ()
       from /usr/local/Qt-6.6.0/lib/libQt6WebEngineCore.so.6
    #4  0x00000210b845c780 in ?? ()
    #5  0x00000210b845c780 in ?? ()
    #6  0x00007fffffffd480 in ?? ()
    #7  0x00007fffe62391bb in QtWebEngineCore::ProfileAdapter::ProfileAdapter(QString const&) ()
       from /usr/local/Qt-6.6.0/lib/libQt6WebEngineCore.so.6

* write stuff to our cache dir, not tmp ;)

I haven't actually checked this fixes an affected version of Qt (need to
rebuild or get from riverbank pypi). But I unpacked the pak file and it
has the right fake URL in it.

2 files changed, 30 insertions, 1 deletions

diff --git a/qutebrowser/app.py b/qutebrowser/app.py
index 778c248c2..4a6284eb1 100644
--- a/qutebrowser/app.py
+++ b/qutebrowser/app.py
@@ -50,7 +50,7 @@ from qutebrowser.keyinput import macros, eventfilter
 from qutebrowser.mainwindow import mainwindow, prompt, windowundo
 from qutebrowser.misc import (ipc, savemanager, sessions, crashsignal,
                               earlyinit, sql, cmdhistory, backendproblem,
-                              objects, quitter, nativeeventfilter)
+                              objects, quitter, nativeeventfilter, pakjoy)
 from qutebrowser.utils import (log, version, message, utils, urlutils, objreg,
                                resources, usertypes, standarddir,
                                error, qtutils, debug)
@@ -76,6 +76,10 @@ def run(args):
     log.init.debug("Initializing config...")
     configinit.early_init(args)
 
+    # Run after we've imported Qt but before webengine is initialized.
+    # TODO: check: backend, Qt version, frozen
+    pakjoy.patch()
+
     log.init.debug("Initializing application...")
     app = Application(args)
     objects.qapp = app
diff --git a/qutebrowser/misc/pakjoy.py b/qutebrowser/misc/pakjoy.py
index cdf2b4744..7e0d139c4 100644
--- a/qutebrowser/misc/pakjoy.py
+++ b/qutebrowser/misc/pakjoy.py
@@ -26,10 +26,14 @@ This is a "best effort" parser. If it errors out, we don't apply the workaround
 instead of crashing.
 """
 
+import os
+import shutil
+import pathlib
 import dataclasses
 from typing import ClassVar, IO, Optional, Dict, Tuple
 
 from qutebrowser.misc import binparsing
+from qutebrowser.utils import qtutils, standarddir
 
 HANGOUTS_MARKER = b"// Extension ID: nkeimhogjdpnpccoofpliimaahmaaome"
 HANGOUTS_ID = 36197  # as found by toofar
@@ -139,6 +143,27 @@ class PakParser:
         raise binparsing.ParseError("Couldn't find hangouts manifest")
 
 
+def patch():
+    resources_path = qtutils.library_path(qtutils.LibraryPath.data) / "resources"
+    work_dir = pathlib.Path(standarddir.cache()) / "webengine_resources_pak_quirk"
+    patched_file = work_dir / "qtwebengine_resources.pak"
+
+    print(f"{work_dir=} {work_dir.exists()=}")
+    print(f"{resources_path=}")
+    if work_dir.exists():
+        shutil.rmtree(work_dir)
+
+    shutil.copytree(resources_path, work_dir)
+
+    with open(patched_file, "r+b") as f:
+        parser = PakParser(f)
+        offset = parser.find_patch_offset()
+        f.seek(offset)
+        f.write(REPLACEMENT_URL)
+
+    os.environ["QTWEBENGINE_RESOURCES_PATH"] = str(work_dir)
+
+
 if __name__ == "__main__":
     import shutil
     shutil.copy("/usr/share/qt6/resources/qtwebengine_resources.pak", "/tmp/test.pak")