Re: [RFC 1/8] UTF helpers

Esko Luontola [off-list ref] writes:

Junio C Hamano wrote on 13.5.2009 21:48:

quoted

If you allow people to record otherwise exactly the same tree object in
different encoding, like you seem to have in mind, subtree comparision
based on the object name will not work and you will end up always
traversing down to the tip, because you won't know if your subtrees need
filename iconv until you recurse into them and actually take a look.

Could you please educate me, that which operations depend on "doing
subtree comparisons based on the object name",

"diff-tree A B" looks at corresponding subtrees of A and B and does not
recurse into the identical subdirectories; "git log -- dir" uses this fact
to speed up the checking of differences.  When a typical commit touches
only a handful of paths in a project with 20k paths, this really matters.

files/functions those comparisons are done? Also, do you mean by
"object name" the SHA1 of the object, the filename of a
file/directory, or something else?

What is colloquially known as SHA-1 has an official terminology; see
Documentation/glossary.txt.