# Buggy code
def _init_js(self):
    js_code = "\n".join(
        [
            '"use strict";',
            "window._qutebrowser = window._qutebrowser || {};",
            utils.read_file("javascript/scroll.js"),
            utils.read_file("javascript/webelem.js"),
            utils.read_file("javascript/caret.js"),
        ]
    )
    script = QWebEngineScript()
    # We can't use DocumentCreation here as WORKAROUND for
    # https://bugreports.qt.io/browse/QTBUG-66011
    script.setInjectionPoint(QWebEngineScript.DocumentReady)
    script.setSourceCode(js_code)

    page = self._widget.page()
    script.setWorldId(QWebEngineScript.ApplicationWorld)

    # FIXME:qtwebengine  what about runsOnSubFrames?
    page.scripts().insert(script)


# Traceback (ValueError)
16:39:44 DEBUG    init       app:_init_modules:468 Initializing websettings...
16:39:45 ERROR    misc       crashsignal:exception_hook:216 Uncaught exception
Traceback (most recent call last):
File "/bin/qutebrowser", line 11, in <module>
load_entry_point('qutebrowser==1.1.1', 'gui_scripts', 'qutebrowser')()
File "/usr/lib/python3.6/site-packages/qutebrowser/qutebrowser.py", line 188, in main
return app.run(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 137, in run
init(args, crash_handler)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 163, in init
_init_modules(args, crash_handler)
File "/usr/lib/python3.6/site-packages/qutebrowser/app.py", line 469, in _init_modules
websettings.init(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 215, in init
webenginesettings.init(args)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 297, in init
websettings.init_mappings(MAPPINGS)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 198, in init_mappings
mapping.set(value)
File "/usr/lib/python3.6/site-packages/qutebrowser/config/websettings.py", line 72, in set
self._set(value, settings=settings)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 154, in _set
filenames = [self._find_installed(code) for code in value]
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 154, in <listcomp>
filenames = [self._find_installed(code) for code in value]
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/webenginesettings.py", line 143, in _find_installed
local_filename = spell.local_filename(code)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 64, in local_filename
all_installed = local_files(code)
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 51, in local_files
for matching_dict in sorted(matching_dicts, key=version, reverse=True):
File "/usr/lib/python3.6/site-packages/qutebrowser/browser/webengine/spell.py", line 36, in version
.format(filename))
ValueError: the given dictionary file name is malformed: /usr/share/qt/qtwebengine_dictionaries/en-US.bdic

# Fixed code
def _init_js(self):
    """Initialize global qutebrowser JavaScript."""
    js_code = javascript.wrap_global(
        "scripts",
        utils.read_file("javascript/scroll.js"),
        utils.read_file("javascript/webelem.js"),
        utils.read_file("javascript/caret.js"),
    )
    # FIXME:qtwebengine what about subframes=True?
    self._inject_early_js("js", js_code, subframes=True)
    self._init_stylesheet()

    greasemonkey = objreg.get("greasemonkey")
    greasemonkey.scripts_reloaded.connect(self._inject_userscripts)
    self._inject_userscripts()