On Mon, Jul 28, 2014 at 5:58 AM, Gilles Dubuc <gilles@wikimedia.org> wrote:

We can definitely add older Operas to the blacklist if they are problematic. First we need to investigate if the issue is at the OOJS level, in which case if might be fixable, since OOJS now supports older ES3 browsers thanks to a shim.

OOJS uses the es5-shim project, which contains two files, es5-shim (polyfills for functions which can be recreated in ES3) and es5-sham (approximate polyfills for functions which provide functionality not available in ES3).

As far as I can see, OOJS pulls in es5-shim as a dependency, but not es5-sham; in other words, it is not actually ES3-compatible. Opera 10 dies because it does not have Object.create which is in es5-sham (there is no way to recreate the "write-protected" behavior it offers in ES3). This seems like an easy fix, but then, if it really was, I assume it would be fixed already...

The other thing is broken is that MediaViewer does not recover from loading errors. This used to work, I'll investigate what happened. (Recovering here means that the first thumbnail click does not work, you get an error popup, but the next one works (MediaViewer uninstalls its click handler on error). Still a bad user experience given that this repeats on all page loads, but better than the current one.)