Make duplicate file assignment deterministic. #222
Description
I've been using phockup to organize a set of camera photos and videos, which I then copy into a flat file structure. I then synchronize both the flat and non-flat organized directories back into the source files using rsync. Lastly, I synchronize both of these files to my phone's camera role with Foldersync for Android.
I've noticed that some files are synchronized every single transfer. Rsync shows a sync for every single file due to checksum and size difference, and when I compare two example files, they show a single byte different:
$ cmp /var/{tmp,share}/camera/20230613-174230-2.mp4 /var/tmp/camera/20230613-174230-2.mp4 /var/share/camera/20230613-174230-2.mp4 differ: byte 807014, line 3188
Tracking this down a bit more, I've noticed this only seems to happen to files that phockup detects as having the same timestamps, ones that generate filenames with the -# appended to the end of them. Some of my files do appear to be different but have the same timestamps. As far as I can tell, the order that phockup decides to assign the duplicate files a discriminating number does not appear stable, so, i.e., one iteration one file might be assigned *-2, and another iteration a different file might be assigned *-2.
Is it possible that the sorting method of identified duplicates could be made stable, so that in these cases, the file contents will not change each iteration? I can fix this on my end by removing duplicates, but it seems suboptimal that phockup might cause files to swap places with every iteration.