It looks like we have a solution to the problem of the user not being able to restore a corrupt document from Versions Browser because the document is corrupt, and so she can’t open it, and so she can’t File > Revert to > Browse All Versions.
The solution is: • Override -[NSDocument openDocumentWithContentsOfURL:display:error:]. • After invoking super, look in returned error for SQLite error code:11, 'database disk image is malformed’. • If that error is found, clear all data from the document on the disk. • In its place, copy in data from a good, empty document. • Invoke super again. The document will open this time. • Display a sheet informing user that document was corrupt and suggest File > Revert to > Browse All Versions. I’ve not written the code yet, just done the above manually with a Core Data SQLite document that has legacy Delete/Rollback journaling. Corruption was simulated by punching out the middle of the file with a hex editor. I also used a hex editor to nuke and pave the document. Result: Versions Browser showed previous versions of the corrupted document, as desired. After restoring one, I was able to edit, save, close, and re-open it and nothing complained. Happily, no reverse engineering of /.DocumentRevisions-V100 was necessary, but I’m still open to any better ideas. Did I miss an easier solution to this problem that is built into Cocoa? I’m aware that the magic in NS(Persistent)Document often comes back to bite with a vengeance days or weeks later. I shall post again if I have any trouble. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
