Framework: Firefox 67.0 breaks Vaadin 8

[jontto]

With the new Firefox release 67.0 Vaadin 8 is broken, both on Linux and Windows 10 machines.

https://demo.vaadin.com/sampler/
Can be opened on Chrome/Chromium and with Firefox 66.0.5 (Windows), but not with FF 67.0 on neither Windows nor Linux.

[samo4b]

I just checked the https://demo.vaadin.com/sampler/ on my Firefox 67.0 as i just updated it and i can confirm this.
In the console i see this error occuring multiple times.
This does not show up in Chrome.

Wed May 22 12:39:09 GMT+200 2019 com.vaadin.client.ApplicationConfiguration SEVERE: (InvalidCharacterError) : String contains an invalid character com.google.gwt.core.client.JavaScriptException: (InvalidCharacterError) : String contains an invalid character at Unknown.kLb(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.VKb(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.vte(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Qse(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.lse(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.wse(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.KOd(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Pic(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Hic(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Wic(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.d3b(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.kec(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.kGc(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Qad(com.vaadin.demo.sampler.AppWidgetSet-3.js) at Unknown.$h(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.di(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Ai(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Di(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Ci/<(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.anonymous(com.vaadin.demo.sampler.AppWidgetSet-3.js) at Unknown.__installRunAsyncCode(https://demo.vaadin.com/sampler/VAADIN/widgetsets/com.vaadin.demo.sampler.AppWidgetSet/com.vaadin.demo.sampler.AppWidgetSet.nocache.js?1558521547992) at Unknown.__gwtInstallCode(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Qi(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.mj(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.anonymous(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Ai(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Di(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.Ci/<(https://demo.vaadin.com/sampler/ line 9 > scriptElement) at Unknown.anonymous(https://demo.vaadin.com/sampler/VAADIN/widgetsets/com.vaadin.demo.sampler.AppWidgetSet/deferredjs/AB8E0A7908A2A696EE46E149915F3EB6/3.cache.js) at Unknown.anonymous(Unknown) line 9 > scriptElement:1:3063

[mstahv]

Basic hello world app created with archetype seems to work. @samo4b was this in your own app or in Sampler?

[Artur-]

The reason is apparently that Firefox has added a feature called U2F, which overrides any variable named u2f. See this https://jsfiddle.net/6cewp2Lj/

[Artur-]

https://bugzilla.mozilla.org/show_bug.cgi?id=1553436

[Artur-]

Seems this was fixed for GWT in https://github.com/gwtproject/gwt/commit/9a9708107b1c460469ec57ba00c2a203703163e5

[TatuLund]

But the seems to be projected to possibly upcoming 2.9 version: https://github.com/gwtproject/gwt/issues/9619

[jontto]

I can confirm that the 8.8-SNAPSHOT version and the released 8.8.2 works also with our internal application with FF 67.0 in Linux and Windows 10 environments.

Good and quick work, team!

[knoobie]

Just wondering if you guys have a deterministic example where the problem occurs. I tested most of our application with 7 and 8 and non had the problem. Is there some kind of special feature we have to use to get this "u2f" generated or just bad luck?

[TatuLund]

You can go to WEB-INF/VAADIN folder and find the actual widgetset file, and decompress it. Then use e.g. grep to check if it contains "u2f".

[Artur-]

Presumably the minifier uses a, b, c,...aa, ab, .... aaa, ... for method names and variables. When you have a large enough widget set then it will get to using u2f at some point

[knoobie]

Thanks Artur and Tatu!

[mstahv]

Additional note: sometimes the app may break at load because of the issue, sometimes during the usage.