- 
    Bug 
- 
    Resolution: Done
- 
    P3: Somewhat important 
- 
    5.13.0
- 
    None
- 
    - Firefox 67.0.4
 - Chromium 75.0.3770.100
 - Emscripten 1.38.32
 - Qt 5.13.0 for WebAssembly (self-compiled with default configure switches)
- 
        
- 
        0f92f2f35d55f2de545e8472c6b240c8fd0bb53f (qt/qtbase/5.13)
When trying to send a custom network request via QNetworkAccessManager::sendCustomRequest, it fails with the following error message (stack-trace attached).
SyntaxError: An invalid or illegal string was specified
After digging around in the Qt sources, I found the problem. In QNetworkReplyWasmImplPrivate::doSendRequest, the method QNetworkReplyWasmImpl::methodName is called to get the HTTP-verb. However, that method completly ignores custom verbs (See https://code.qt.io/cgit/qt/qtbase.git/tree/src/network/access/qnetworkreplywasmimpl.cpp#n208)!