add sync mode that is like -batch if no conflicts, but prompts like -auto if there are

[Dromantor]

What I'm most missing is a way to automatically sync without any interaction when there is no conflict like -batch does, but prompt the user what to do when one arises like -auto does.

I have a batch file calling unison for each project directory I'm mirroring from a NAS. Currently I'm syncing with -auto because I want to be able to handle conflicts when they arise (multi user environment, so this could happen), but then I have to confirm Proceed with propagating updates? [] each time. With -batch on the other hand any collisions would get ignored and I'd had to pause at the end of the batch file and manually review the output each time, or first run everything with -batch, and then everything again with -auto to fix collisions, which isn't great ...

A -prompt-on-conflict flag or -batch-prompt mode would be great. Or a way to set the default action of Proceed with propagating updates? [] to "y" so -auto just works as I want.

If this is already possible please point me in the right direction, I couldn't find it in the manual.

[gdt]

This is a reasonable request; pull requests welcome.