There were duplicate script pieces to help comparing diff
output, which this patch consolidates into the t/diff-lib.sh
library.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The score number that follow R/C status were parsed but the
parse pointer was not updated, causing the entire line to become
unrecognized. This patch fixes this problem.
There was a test missing to catch this breakage, which this
commit adds as t4009-diff-rename-4.sh. The diff-raw tests used
in related t4005-diff-rename-2.sh (the same test without -z) and
t4007-rename-3.sh were stricter than necessarily, despite that
the comment for the tests said otherwise. This patch also
corrects them.
The documentation is updated to say that the status can
optionally be followed by a number called "score"; it does not
have to stay similarity index forever and there is no reason to
limit it only to C and R.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
For later stages to reorder patches, pruning logic and rename detection
logic should not decide which delete to discard (because another entry
said it will take over the file as a rename) until the very end.
Also fix some tests that were assuming the earlier "last one is rename
or keep everything else is copy" semantics of diff-raw format, which no
longer is true.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This changes the diff-raw format again, following the mailing
list discussion. The new format explicitly expresses which one
is a rename and which one is a copy.
The documentation and tests are updated to match this change.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The rename/copy detection logic in earlier round was only good
enough to show patch output and discussion on the mailing list
about the diff-raw format updates revealed many problems with
it. This patch fixes all the ones known to me, without making
things I want to do later impossible, mostly related to patch
reordering.
(1) Earlier rename/copy detector determined which one is rename
and which one is copy too early, which made it impossible
to later introduce diffcore transformers to reorder
patches. This patch fixes it by moving that logic to the
very end of the processing.
(2) Earlier output routine diff_flush() was pruning all the
"no-change" entries indiscriminatingly. This was done due
to my false assumption that one of the requirements in the
diff-raw output was not to show such an entry (which
resulted in my incorrect comment about "diff-helper never
being able to be equivalent to built-in diff driver"). My
special thanks go to Linus for correcting me about this.
When we produce diff-raw output, for the downstream to be
able to tell renames from copies, sometimes it _is_
necessary to output "no-change" entries, and this patch
adds diffcore_prune() function for doing it.
(3) Earlier diff_filepair structure was trying to be not too
specific about rename/copy operations, but the purpose of
the structure was to record one or two paths, which _was_
indeed about rename/copy. This patch discards xfrm_msg
field which was trying to be generic for this wrong reason,
and introduces a couple of fields (rename_score and
rename_rank) that are explicitly specific to rename/copy
logic. One thing to note is that the information in a
single diff_filepair structure _still_ does not distinguish
renames from copies, and it is deliberately so. This is to
allow patches to be reordered in later stages.
(4) This patch also adds some tests about diff-raw format
output and makes sure that necessary "no-change" entries
appear on the output.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
