Re: Prepare "git-merge-tree" for future work

Linus Torvalds [off-list ref] writes:

In contrast, the ones to diff_filespec I've never really used, and I did 
not want to compare blob objects, I very much wanted to compare in-memory 
buffers (_and_ potentially blobs).

So if you can show an easy example of how to populate a set of filespec 
pairs (not with blobs - with in-memory generated data) and insert them 
onto the lists, that would be good.

Ah, I see.  Your origin() function always returns a in-core
buffer from an existing blob (or NULL if it is a new file) but
result() returns either an existing blob resulting from the
tree-level merge, or a 3-way content merge result that does not
have an existing blob, and it is not obvious how to express the
latter as a filespec (all other cases you can stuff the blob
object name in the sha1[] member and if you choose to do the
read_sha1_file() yourself store the result in data member or you
can let diff_populate_filespec() read the data when diff
machinery needs it).

I think a filespec that has 0{40} sha1, with data already
populated and should_free/should_munmap members both set to
false might work for the in-memory data but I haven't tried.

I'd take the hint, and I will (eventually) take a look at it
if nobody beats me to it, but most likely not now, sorry.