I am using the demo browser provided by Qt source and configure to use proxy server which requiring basic username/password authentication to access the internet.
At first, an proxy authentication dialog has prompted as expected when tring to load webpage，however, I did not provide any information about username/password and I just click the "cancel" button. After that, the authentication dialog will never prompted again when I'm tring to load any other webpages ，so I will never get the chance to provide username/password again.
I have examined the source code of demo browser as well as QtNetwork module, and find out the reason is after I cancelled the authentication dialog "proxyAuthenticationRequired" signal will never be emitted by QNetworkAccessManager. The suspicious code is as follows：
In above code，emit "proxyAuthenticationRequired" signal will be bypassed when condition "proxy != backend->reply->lastProxyAuthentication" evaluates to true. My question is why this condition is true when authentication dialog has been cancelled?
Can anybody tell me whether it is a QT bug ? And is there better practice to support HTTP proxy authentication?
Thanks for your help!