qt_message_fatal crashes if context.file is empty

Not sure if this is a WebEngine issue or just a QtCore issue, but it crashes on my anytime it logs a fatal error.

One way to duplicate this is to remove Qt's bin directory from your Windows PATH variable, and make sure QtWebEngineProcess.exe is NOT in the same folder as your executable. When you try to run and load a QtWebEngineView, you'll get a console.log message echo'd about how it can't find QtWebEngineProcess.exe. But it will ALSO crash, with this stack trace:

Qt5Cored.dll!convert_to_wchar_t_elided(wchar_t * d, unsigned int space, const char * s) Line 256 C++
Qt5Cored.dll!qt_message_fatal(QtMsgType __formal, const QMessageLogContext & context, const QString & message) Line 1593 C++
Qt5Cored.dll!QMessageLogger::fatal(const char * msg, ...) Line 784 C++
Qt5WebEngineCored.dll!`anonymous namespace'::subProcessPath(void) C++
Qt5WebEngineCored.dll!WebEngineLibraryInfo::getPath(int) C++
Qt5WebEngineCored.dll!WebEngineContext::WebEngineContext(void) C++
Qt5WebEngineCored.dll!WebEngineContext::current(void) C++
Qt5WebEngineCored.dll!QtWebEngineCore::BrowserContextAdapter::defaultContext(void) C++
> Qt5WebEngineWidgetsd.dll!QWebEngineProfile::defaultProfile() Line 516 C++

The crash dialog gives this:

Problem signature:
Problem Event Name: BEX
Application Name: qxs.exe
Application Version: 2017.0.0.23696
Application Timestamp: 56c25435
Fault Module Name: StackHash_0a9e
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 00000000
Exception Offset: 00000000
Exception Code: c0000005
Exception Data: 00000008
OS Version: 6.1.7601.2.1.0.256.27
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

For some reason the debugger won't let me step in past the QWebEngineProfile::defaultProfile() call, so I can't see why it's crashing in qt_message_fatal. Fortunately, enough information was echo'd to the console prior to the crash that I could figure out what the problem was.

I've had other crashes (reported elsewhere) in QtWebEngine that also crash when it's logging an error message.