Re: CFT: merge-recursive in C (updated)

fork0@t-online.de (Alex Riesen) writes:

this broke t6022-merge-rename.sh (the second test). It produces an
index with this:

.../t/trash$ git-diff-index white
:100644 100644 2d603156dc5bdf6295c789cac08e3c9942a0b82a 0000000000000000000000000000000000000000 M      B
:100644 100644 ba41fb96393979b22691106b06bf5231eab57b85 0000000000000000000000000000000000000000 M      N

whereas git-merge-recursive (and the previous version, without pipe):

.../t/trash$ git-diff-index white
:100644 100644 2d603156dc5bdf6295c789cac08e3c9942a0b82a 0000000000000000000000000000000000000000 M      B

I can see that "git update-index --add" is somehow different from a
pipe to "git update-index --index-info", but not very clear. Does this
"zero-sha1" mean that the file "N" is not in the index?

When diff-index and diff-files compare a tree entry or an index
entry with a file in the working tree, they do not compute the
blob hash value for the file in the working tree.  0{40} is used
on the RHS in such a case.  When the working tree file matches
the corresponding index entry, then we know RHS matches what is
in the index, so both sides have the blob hash value.