I want to set up the window icon for a DocumentWindow, at the moment it's always showing some default icon. The window is using a native title bar. Calling window->setIcon(img) doesn't have any effect in this case (it just repaint the title bar drawn by JUCE if present), so I would call window->getPeer()->setIcon(img).
But this call doesn't have any effect either. I can call setIcon before or after the window is visible. It just doesn't work. The only way I can make it work is by inserting a call to setIcon() with some hard coded image just before the call to XMapWindow in LinuxComponentPeer::setVisible(). So maybe X11 requires the icon to be set before mapping the window?