Please don't add non-model arguments to setModel calls.

Sorry, but I don't think this is important enough to change the interface or introduce extra complexity at all.

I also wonder why this doesn't go right by default. Shouldn't it inherit the parent window icon? Or how does this work?

LOL, this can be done just like with the about-Qt dialog ... I don't even need to pass something new ;), so you are right.

Updated to an easy fix, but I don't know, why they don't use the testnet icon as default. At lest now every GUI element uses it, while we are on testnet :).

Edit: The Main-Window window icon is changed to testnet in BitcoinGUI::setClientModel(), perhaps the following dialogs still use what was default at compile-time?

Yeah, I wonder where it gets the 'non-testnet' icon from at all? If new dialogs can somehow still find it, that means it is still stored somewhere, which is not right. We need to figure this out, so all the explicit setWindowIcons can go.

maybe qApp->setWindowIcon ?

Can qApp be freely used in bitcoingui.cpp? I'll try this.

Alright this fixes it! Will update this pull.

Updated!

You still need to set the window icon of the current window as well... It will only change the default for new dialogs/windows.

That is strange, as this works like it should. If I use normal net, the icon is correct on every dialog, the same for testnet.

As we call setClientModel() on Init, the icon set should be a global one, what am I understanding wrong here?

Ok, maybe this just works then.

On Ubuntu, this causes no dock icon to be shown at all anymore (either in testnet or normal net).
You do need to set the setWindowIcon on the BitcoinGUI instance as well, in both places where you set it in qApp. The qApp icon is only applied automatically to windows constructed after it is set. The BitcoinGUI instance already exists at that time.

So just re-add setWindowIcon(QIcon(":icons/bitcoin")); below the qApp-> lines?

Yes

Done and this work on Ubuntu now, too so that you have testnet-symbol on every dialog while on testnet?

Yep it works great with this. However, ubuntu doesn't show a symbol for every window, just for the application, so I can't check the second part. I assume it is OK though everywhere now.