Damaged UTI Gets restored from iCloud Backup

Number:rdar://32446751 Date Originated:28 may 2017
Status:Duplicate/6178283 Resolved:
Product:iCloud Product Version:10.3
Classification:Serious Bug Reproducible:Always
I had a messed up UTI for com.adobe.pdf which caused UIDocumentMenuViewController to fail to show any document provider locations. Since there is no facility to reset the UTI database to what is defined by the system plus installed apps, I tried to reset and restore my iPhone. But the restore caused the problem to reappear.

Steps to Reproduce:
I suspect that you can corrupt the com.adobe.pdf UTI by having an app define another UTI that has no conformance to any parent types. Then this UTI declaration will be restored from an iCloud backup.

Expected Results:
Restoring an iCloud backup should restore the UTI database to what is defined by the OS plus only what is defined by installed apps.

Observed Results:
Restoring an iCloud backup restored a faulty UTI which overrode the com.adobe.pdf UTI defined by the system.


Please refer to my blog post https://www.cocoanetics.com/2017/05/document-menu-view-controller-not-showing-locations/ for details about the defunct UTI and the problem this caused.


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