[PATCH] Add -B flag to diff-* brothers.
authorJunio C Hamano <junkio@cox.net>
Mon, 30 May 2005 07:08:37 +0000 (00:08 -0700)
committerLinus Torvalds <torvalds@ppc970.osdl.org>
Mon, 30 May 2005 17:35:49 +0000 (10:35 -0700)
commitf345b0a066572206aac4a4f9a57d746e213b6bff
tree60d5548ce7ca6e62b8b934cc016c01ddb373c3fb
parent2cd68882ee8629f9782be017007fff4c78e45e45
[PATCH] Add -B flag to diff-* brothers.

A new diffcore transformation, diffcore-break.c, is introduced.

When the -B flag is given, a patch that represents a complete
rewrite is broken into a deletion followed by a creation.  This
makes it easier to review such a complete rewrite patch.

The -B flag takes the same syntax as the -M and -C flags to
specify the minimum amount of non-source material the resulting
file needs to have to be considered a complete rewrite, and
defaults to 99% if not specified.

As the new test t4008-diff-break-rewrite.sh demonstrates, if a
file is a complete rewrite, it is broken into a delete/create
pair, which can further be subjected to the usual rename
detection if -M or -C is used.  For example, if file0 gets
completely rewritten to make it as if it were rather based on
file1 which itself disappeared, the following happens:

    The original change looks like this:

file0     --> file0' (quite different from file0)
file1     --> /dev/null

    After diffcore-break runs, it would become this:

file0     --> /dev/null
/dev/null --> file0'
file1     --> /dev/null

    Then diffcore-rename matches them up:

file1     --> file0'

The internal score values are finer grained now.  Earlier
maximum of 10000 has been raised to 60000; there is no user
visible changes but there is no reason to waste available bits.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
13 files changed:
Documentation/git-diff-cache.txt
Documentation/git-diff-files.txt
Documentation/git-diff-tree.txt
Makefile
diff-cache.c
diff-files.c
diff-tree.c
diff.c
diff.h
diffcore-break.c [new file with mode: 0644]
diffcore-rename.c
diffcore.h
t/t4008-diff-break-rewrite.sh [new file with mode: 0644]