Re: [PATCH v2 1/2] xdiff: implement a zealous diff3, or "zdiff3"

Hi Elijah

On 18/09/2021 23:04, Elijah Newren wrote:

Hi Phillip,
[...]

quoted

I do wonder (though a brief try failed to trigger it) if there are cases
where the diff algorithm does something "clever" which means it does not
treat a common prefix or suffix as unchanged (see d2f82950a9
("Re(-re)*fix trim_common_tail()", 2007-12-20) for a related issue). We
could just trim the common prefix and suffix from the two sides
ourselves using xdl_recmatch().

You seem to understand the xdl stuff much better than I.  I'm not sure
how xdl_recmatch() would be called or where.  Would you like to take
over the patches?

I could do if you really want but I wont have time to do anything for at 
least a couple of weeks (I really need to get on top of my current 
series before starting anything new). I outlined the rough idea in [1]. 
tldr; instead of diffing the two sides of the conflict just walk the 
start and the end of the two sides until we find a line that does not match.

Best Wishes

Phillip

[1] 
https://lore.kernel.org/git/f76c79d6-f280-3011-d88d-6de146977626@gmail.com/ (local)