[browser] hyperlinks with target="_blank" do not open

Rachel, can you please detail the steps you’re taking to reproduce this bug? It’s unclear to me from where I should be clicking on an external link.

Olivier, please do the following:

Click on Twitter app
Login
On the 'home' tab and look for an article with a URL
Try clicking on the URL, you can select it but it doesn't load the page (either on the web app or open it from the browser)

Got it, I can reproduce. After some investigation, it turns out the link in tweets have the "target" attribute set to "_blank", which is a special, deprecated way of requesting to open a new window/tab. It appears the webview doesn’t handle this well by default. I need to look into how we can support them (for now we’d just open them in the same view, ignoring the target attribute).

This seems to be a bug in webkit itself. When clicking a link that has "target=_blank", the navigationRequested() signal (http://doc-snapshot.qt-project.org/5.0/qtwebkit/qml-qtwebkit3-webview.html#onNavigationRequested-signal) is not emitted.

Related upstream bug reports:
  https://bugs.webkit.org/show_bug.cgi?id=76416
  https://bugs.webkit.org/show_bug.cgi?id=91779

What’s missing on the webkit side is apparently for QtWebPagePolicyClient to implement the decidePolicyForNewWindowAction(…) callback. This doesn’t seem to be implemented, even in the latest trunk.

Until a real fix is implemented in webkit, we might be able to work around the problem by using javascript event delegation to install a handler for the page when it’s loaded and intercept all hyperlink activations.

I have linked a branch that implements the suggested idea (use javascript event delegation to install a handler for the page when it’s loaded and intercept all hyperlink activations). This works very well for normal hyperlinks with target = "_blank".

However, it looks like twitter does additional processing of those links. According to the webkit web inspector, an event listener is installed on the document (from https://platform.twitter.com/widgets.js) which does the following:

    function p(a) {
        a = a || window.event;
        var b = a.target || a.srcElement, c, d, e;
        while (b && b.nodeName.toLowerCase() !== "a") b = b.parentNode;
        b && b.nodeName.toLowerCase() === "a" && b.href && (c = b.href.match(f), c && (e = o(b.href), e = e.replace(/^http[:]/, "https:"), e = e.replace(/^\/\//, "https://"), q(e, b), a.returnValue = !1, a.preventDefault && a.preventDefault()));
    }

So, for some reason that I don’t fully understand yet, this listener cancels the event without stopping further propagation of it (see https://developer.mozilla.org/en-US/docs/DOM/event.preventDefault). I suspect this listener is what prevents my custom handler from getting the click event. Needs more investigation.

When testing on Facebook app, and finding a bitly link as an example it does nothing when you click on the link. Need to investigate if this is a similar issue to Twitter.

The fix that was just committed doesn’t address the issue originally reported, because of the additional processing that twitter does of those links. I filed bug #1159857 to track this issue separately.

Fixed in webbrowser-app 0.17.