Don't overwrite files.

[jtagcat]

Input:

o1_foo.png
o1_bar.png
o1_baz.png
o2_baz.png

ls | wc -l # 4
vimv transform:

foo.png
bar.png
baz.png
bar.png

result:

foo.png
bar.png
baz.png

---

Either fail, or present the conflicted files (with possibly the original name as well, bonus points for checksum) only the second time.

[uunnxx]

Yes, we need something to prevent accidentally deleting conflicted (same name) files.

[opello]

This also manifests when renaming a list of files that happen to share a running number. For example, from an empty test directory:

echo 01 > 01.txt
echo 02 > 02.txt
echo 03 > 03.txt

Run vimv and use Ctrl-a on each line to change 01 to 02, 02 to 03, and 03 to 04. The result will be a single file remaining in the directory called 04.txt that contains 01 because the operations were performed in order.