[PATCH] Redo rename/copy detection logic.

[PATCH] Redo rename/copy detection logic.

Earlier implementation had a major screw-up in the memory
management area.  Rename/copy logic sometimes borrowed a pointer
to a structure without any provision for downstream to determine
which pointer is shared and which is not.  This resulted in the
later clean-up code to sometimes double free such structure,
resulting in a segfault.  This made -M and -C useless.

Another problem the earlier implementation had was that it
reordered the patches, and forced the logic to differentiate
renames and copies to depend on that particular order.  This
problem was fixed by teaching rename/copy detection logic not to
do any reordering, and rename-copy differentiator not to depend
on the order of the patches.  The diffs will leave rename/copy
detector in the same destination path order as the patch that
was fed into it.  Some test vectors have been reordered to
accommodate this change.

It also adds a sanity check logic to the human-readable diff-raw
output to detect paths with embedded TAB and LF characters,
which cannot be expressed with that format.  This idea came up
during a discussion with Chris Wedgwood.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>