This cleans up the way calls are made into the diff core from diff-tree
family and diff-helper. Earlier, these programs had "if
(generating_patch)" sprinkled all over the place, but those ugliness are
gone and handled uniformly from the diff core, even when not generating
patch format.
This also allowed diff-cache and diff-files to acquire -R
(reverse) option to generate diff in reverse. Users of
diff-tree can swap two trees easily so I did not add -R there.
[ Linus' note: I'll add -R to "diff-tree" too, since a "commit
diff" doesn't have another tree to switch around: the other
tree is always the parent(s) of the commit ]
Also -M<digits-as-mantissa> suggestion made by Linus has been
implemented.
Documentation updates are also included.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>