Security Error on WebWorker IE11 Win8.1

[michelson]

Hello , we have found some security issues on windows explorer 11.
the specific error is on the blob url initialization for web worker. The bug is documented here. , it seems to be a bug on previous versions of IE11. The problem is that the mapboxgl.supported() still returns true. So, I see two options , mapboxgl.supported() should return false or patch WebWorker initialization with an strategy similar to https://github.com/parallel-js/parallel.js/pull/16/files

I think this is actually related with #2504

[michelson]

some references: we are using latest version of mapbox ( 0.32.1 )

[andrewharvey]

I don't think it's related to #2504, in that I was getting multiple "Unimplemented type: 3" errors because my version of IE11/specific set of windows patches had a broken gzip which meant that the pbf vector tiles weren't being uncompressed by the browser.

[michelson]

hi @andrewharvey, I know, it's not strictly related, but is related in the sense that mapboxgl.support() is returning true, but the map throws an error.
we indeed thought that the error we had was the #2504, but then with some debugging we realise that it was a Web Worker blob issue.

[fabiomcosta]

I just noticed the same issue.
Maps won't show up on IE11.
Debugging I could see that the error happens on the following line:

mapbox-gl-js/src/util/browser/web_worker.js

Line 8 in b9e10b9

return new window.Worker(workerURL);

@andrewharvey does this helps? Let me know if you need more information.

[anandthakker]

Since this issue is fixed in current versions, I think fixing supported() to correctly return false should be sufficient.

[droachrkn]

This issue has not been fixed. Using the latest map box GL, IE 11 still throws the same error. This is not related to anything within this chain or otherwise. "Security Error", debugger pauses on the WebWorker.

@anandthakker