WebView title is sometimes null when it shouldn't be - webkit

Question

I'm writing a simple browser in Vala and WebKitGTK+.
One of the things I need to do is set the window's title to that of the webpage title, so I monitor title changes with web_view.notify["title"].connect. However, sometimes the value of title is null, when it obviously shouldn't be.
Some examples I remember:
Search anything in Google. Going to the next results page sets the title to null.
Click on an anchor link (e.g. http://example.com/page.html#section)
In any case, using the Web Inspector shows that the pages do have a title set.
Is this a bug I should report? Or maybe I'm doing something wrong? Here's the code I'm using:
//valac --thread --pkg webkitgtk-3.0 --pkg gtk+-3.0 --vapidir=./ test.vala
//The vapidir folder should have webkitgtk-3.0.vapi and webkitgtk-3.0.deps
using WebKit;
using Gtk;
public class Test : Gtk.Window {
public WebView webview;
public Test () {
this.title = "Test";
this.window_position = Gtk.WindowPosition.CENTER;
this.set_default_size (800, 600);
this.hide_titlebar_when_maximized = false;
this.destroy.connect (() => {
Gtk.main_quit ();
});
var scroll = new ScrolledWindow (null, null);
this.webview = new WebView ();
this.add (scroll);
scroll.add (webview);
webview.settings.enable_developer_extras = true;
webview.notify["title"].connect ((sender, property) => {
if (webview.title != null) {
this.title = webview.title;
stdout.printf (webview.title + "\n");
} else {
stdout.printf ("(null)\n");
}
});
webview.web_inspector.inspect_web_view.connect ((p0) => {
var w = new Window ();
w.window_position = WindowPosition.CENTER;
w.title = "Inspector";
w.set_default_size (800,600);
WebView view = new WebView ();
unowned WebView view2 = view;
w.add (view2);
w.show_all ();
return view2;
});
}
public static int main (string[] args) {
Gtk.init (ref args);
Test app = new Test ();
app.webview.load_uri ("http://google.com");
app.show_all ();
Gtk.main ();
return 0;
}
}

Answer 1

There is a signal called title_changed for that purpose and you should always use the signals provided by webkitgtk instead of the GLib notify feature.
(GLib notify is emitted each time a value changes, even if the change is just for the purpose of clearing the old value, such as in your case.)