[Shotwell] Strange behaviour when Adjusting Date in Event View

[Dougie Nisbet]

Not sure if this is a bug.

I noticed that a few photos in my Event View for Mon 8 Sep 2003 were 
misdated, and should be in 9 Aug 2003. So I selected them and adjusted 
the date. As soon as I did this, *all* the photos in 8 Sep 2003 were 
moved to 9 Aug 2003.

To test, I did an Undo, then selected a single image and Adjusted the 
date again. Once more, all the 103 photos in 8 Sep were recategorised 
into 9 Aug 2003.

There may be something else going on here, such as malformed exif data 
in the images concerned. Interested to know if it's just me, and will do 
a few more exhaustive tests as and when required.

Dougie