[whatwg] IE10 inconsistency with Blob / createObjectURL

Jonas Sicking jonas at sicking.cc
Sun Feb 2 14:37:39 PST 2014

Yup, this seems like a bug in IE. Microsoft doesn't read this list
though, so I suggest contacting them directly.

You might also want to file a bug against the File spec to get the
spec to be even more explicit about the requirements here.


/ Jonas

On Fri, Jan 31, 2014 at 6:48 PM, K. Gadd <kg at luminance.org> wrote:
> Apologies if this has come up on the list before:
> IE10 appears to have shipped implementations of the Blob constructor along
> with createObjectURL. While they work, there appears to be a significant
> deviation from the spec behavior (at the very least, Firefox and Chrome
> implement these APIs as I'd expect).
> When a Blob gets GCed in IE10, it appears to intentionally destroy the
> object URL associated with it, instead of waiting for you to revoke the
> object URL. When this happens it spits out a vague console message:
> HTML7007: One or more blob URLs were revoked by closing the blob for which
> they were created. These URLs will no longer resolve as the data backing
> the URL has been freed.
> This is confusing because the API doesn't even have a way to 'close' blobs;
> all that is necessary to trigger this is to let a Blob get collected by
> going out of scope.
> From reading the spec I don't see any language that suggests this behavior
> is allowed or expected. I can try to work around it by retaining all the
> blobs but it seems unnecessary...
> -kg

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