Open Radar

 
Summary:

When recovering data from Time Machine, some directories fail due to permission restrictions.

Steps to Reproduce:

(Using the calendar as an example, however, I have seen this behaviour in other directories)

Create some calendar entries in iCal.
Backup ~/Library/Calendars via Time Machine.
Create some new calendar entries, delete others.
Quit iCal.
Recover the older version of ~/Library/Calendars from Time Machine.

Expected Results:

At first a pop-up should appear and ask if the existing ~/Library/Calendars directory should be replaced, copied or if the recovery should be cancelled.
In both recovery cases, (keep both and replace), the recovery should proceed and finish successfully.

Actual Results:

The expected pop-up appears.

Selecting "keep both" renames the existing directory, creates a new ~/Library/Calendars directory and the first calendar directory below that, before complaining about permission restrictions and aborting - result: an empty iCal.

Selecting "Replace" causes the contents of ~/Library/Calendars to be completely deleted before a new ~/Library/Calendars directory and the first calendar directory below it are created. Again, recovery is aborted due to permissions problems. Again, iCal is left empty - any data which may still have existed is gone. (This is also the reason I categorised this problem as "Crash/Hang/Data Loss")

Regression:

Notes:

I was able to work around this problem by using the shell to copy the files manually from Time Machine to ~/Library as follows:

% rm -rf ~/Library/Calendars
% cd /Volumes/Archive/Backups.backupdb/<machine>/<timestamp>/<volumename>/Users/<user>/Library
% cp -rp Calendars ~/Library/

This worked flawlessly, iCal shows all calendar events as expected!
So why did it fail using Time Machine?