I could in the end test the 2.12 from PPA.
It does not improve the situation.
Reproducing is very easy: select many pictures at once, then press on "F2" and wait for minutes at 100% CPU for the dialog to appear. Then, the rename itself is pretty fast.
I would say that it is reading every pictures, fully, several times each.
I'm at the moment testing with a set of 420 JPEG pictures in the 4-6MB range.
I could in the end test the 2.12 from PPA.
It does not improve the situation.
Reproducing is very easy: select many pictures at once, then press on "F2" and wait for minutes at 100% CPU for the dialog to appear. Then, the rename itself is pretty fast.
I would say that it is reading every pictures, fully, several times each.
I'm at the moment testing with a set of 420 JPEG pictures in the 4-6MB range.
Honestly, this should be forwarded upstream.