Bug 188438 – Storing blobs in IDB on iOS: "Error preparing blob/file"

• Component: New Bugs
• Status: RESOLVED FIXED

[Jake Archibald]

I'm seeing reports of this error on iOS 11.4.1:

https://github.com/jakearchibald/idb/issues/58
https://github.com/localForage/localForage/issues/834

It doesn't seem to happen on all devices, but I've seen it on a colleague's device.

Test: https://static-misc.glitch.me/idb-blob-test - you should see a picture of a cat.

[Jake Archibald]

I haven't been able to recreate it on an iOS simulator.

[Radar WebKit Bug Importer]

<rdar://problem/43097279>

[Sihui Liu]

Created attachment 354759 [details]
Patch

[Alex Christensen]

Comment on attachment 354759 [details]
Patch

This should have a test so we don't regress it again.

[Sihui Liu]

Created attachment 354939 [details]
Patch

[Chris Dumez]

Comment on attachment 354939 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=354939&action=review

> Source/WebCore/ChangeLog:9
> +        Since network process always has access to temp folder now, we don't need to grant access to each temp file.

"Since network process always has access to temp folder now".
-> You mean that you are introducing this behavior in this patch right? This is not pre-existing behavior right? If so, the change log should be clearer about that. It seems we are granting wider sandbox access to the network process with your patch and it is important to point out.

> Source/WebCore/ChangeLog:11
> +        No behavior change. Make three existing tests pass on iOS device. 

Sounds like a behavior change to me no? Presumably there was some use-case that was broken / did not work before and now works?

[Sihui Liu]

(In reply to Chris Dumez from comment #6)
> Comment on attachment 354939 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=354939&action=review
> 
> > Source/WebCore/ChangeLog:9
> > +        Since network process always has access to temp folder now, we don't need to grant access to each temp file.
> 
> "Since network process always has access to temp folder now".
> -> You mean that you are introducing this behavior in this patch right? This
> is not pre-existing behavior right? If so, the change log should be clearer
> about that. It seems we are granting wider sandbox access to the network
> process with your patch and it is important to point out.
> 

This is specified in Source/WebKit/ChangeLog. Will add to this one also.

> > Source/WebCore/ChangeLog:11
> > +        No behavior change. Make three existing tests pass on iOS device. 
> 
> Sounds like a behavior change to me no? Presumably there was some use-case
> that was broken / did not work before and now works?

We expected network process had access to temp folder in our code, so I though this is an "old" behavior which doesn't work... Will remove the "No behavior change".

[Sihui Liu]

Created attachment 354959 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 354959 [details]
Patch

Clearing flags on attachment: 354959

Committed r238283: <https://trac.webkit.org/changeset/238283>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Daniel Westendorf]

I'm seeing this issue again on iOS 14.5 (18E5140k). The error is not present in 14.5 (18E5140i) or iOS 14.4.

UnknownError: Error preparing Blob/File data to be stored in object store

[Daniel Westendorf]

Regression no longer present in 14.5 (18E5154f), sorry for the noise.

[Neil Kinnish]

I'm still seeing this issue and can easily re-create by opening Safari in private browsing on 14.7.1