On Thu, 29 Nov 2007, Jeff King wrote:
>
> I think it will get worse, because you are simultaneously calculating
> all of the similarity scores bit by bit rather than doing a loop. Though
> perhaps you mean at the end you will end up with a list of src/dst pairs
> sorted by score, and you can loop over that.

Well, after thinking about this a bit, I think there's a solution that may
work well with the current thing too: instead of looping just *once* over
the list of rename pairs, loop twice - and simply refuse to do copies on
the first loop.

This trivial patch does that, and turns Kumar's test-case into a perfect
rename list.

It's not pretty, it's not smart, but it seems to work. There's something
to be said for keeping it simple and stupid.

And it should not be nearly as expensive as it may _look_. Yes, the loop
is "(i = 0; i < num_create * num_src; i++)", but the important part is
that the whole array is sorted by rename score, and we have a

	if (mx[i].score < minimum_score)
		break;

in it, so uthe loop actually would tend to terminate rather quickly.

Anyway, Kumar, the thing to take away from this is:

 - git really doesn't even *care* about the whole "rename detection"
   internally, and any commits you have done with renames are totally
   independent of the heuristics we then use to *show* the renames.

 - the rename detection really is for just two reasons: (a) keep humans
   happy, and keep the diffs small and (b) help automatic merging across
   renames. So getting renames right is certainly good, but it's more of a
   "politeness" issue than a "correctness" issue, although the merge
   portion of it does matter a lot sometimes.

 - the important thing here is that you can commit your changes and not
   worry about them being somehow "corrupted" by lack of rename detection,
   even if you commit them with a version of git that doesn't do rename
   detection the way you expected it. The rename detection is an
   "after-the-fact" thing, not something that actually gets saved in the
   repository, which is why we can change the heuristics _after_ seeing
   examples, and the examples magically correct themselves!

 - try out the two patches I've posted, and see if they work for you. They
   pass the test-suite, and the output for your example commit looks sane,
   but hey, if you have other test-cases, try them out.

Here's Kumar's pretty diffstat with both my patches:

	 Makefile                                         |    6 +++---
	 board/{cds => freescale}/common/cadmus.c         |    0
	 board/{cds => freescale}/common/cadmus.h         |    0
	 board/{cds => freescale}/common/eeprom.c         |    0
	 board/{cds => freescale}/common/eeprom.h         |    0
	 board/{cds => freescale}/common/ft_board.c       |    0
	 board/{cds => freescale}/common/via.c            |    0
	 board/{cds => freescale}/common/via.h            |    0
	 board/{cds => freescale}/mpc8541cds/Makefile     |    0
	 board/{cds => freescale}/mpc8541cds/config.mk    |    0
	 board/{cds => freescale}/mpc8541cds/init.S       |    0
	 board/{cds => freescale}/mpc8541cds/mpc8541cds.c |    0
	 board/{cds => freescale}/mpc8541cds/u-boot.lds   |    4 ++--
	 board/{cds => freescale}/mpc8548cds/Makefile     |    0
	 board/{cds => freescale}/mpc8548cds/config.mk    |    0
	 board/{cds => freescale}/mpc8548cds/init.S       |    0
	 board/{cds => freescale}/mpc8548cds/mpc8548cds.c |    0
	 board/{cds => freescale}/mpc8548cds/u-boot.lds   |    4 ++--
	 board/{cds => freescale}/mpc8555cds/Makefile     |    0
	 board/{cds => freescale}/mpc8555cds/config.mk    |    0
	 board/{cds => freescale}/mpc8555cds/init.S       |    0
	 board/{cds => freescale}/mpc8555cds/mpc8555cds.c |    0
	 board/{cds => freescale}/mpc8555cds/u-boot.lds   |    4 ++--
	 23 files changed, 9 insertions(+), 9 deletions(-)

and here it is before:

	 Makefile                                           |    6 +-
	 board/cds/mpc8548cds/Makefile                      |   60 -----
	 board/cds/mpc8555cds/Makefile                      |   60 -----
	 board/cds/mpc8555cds/init.S                        |  255 --------------------
	 board/cds/mpc8555cds/u-boot.lds                    |  150 ------------
	 board/{cds => freescale}/common/cadmus.c           |    0
	 board/{cds => freescale}/common/cadmus.h           |    0
	 board/{cds => freescale}/common/eeprom.c           |    0
	 board/{cds => freescale}/common/eeprom.h           |    0
	 board/{cds => freescale}/common/ft_board.c         |    0
	 board/{cds => freescale}/common/via.c              |    0
	 board/{cds => freescale}/common/via.h              |    0
	 board/{cds => freescale}/mpc8541cds/Makefile       |    0
	 board/{cds => freescale}/mpc8541cds/config.mk      |    0
	 board/{cds => freescale}/mpc8541cds/init.S         |    0
	 board/{cds => freescale}/mpc8541cds/mpc8541cds.c   |    0
	 board/{cds => freescale}/mpc8541cds/u-boot.lds     |    4 +-
	 .../mpc8541cds => freescale/mpc8548cds}/Makefile   |    0
	 board/{cds => freescale}/mpc8548cds/config.mk      |    0
	 board/{cds => freescale}/mpc8548cds/init.S         |    0
	 board/{cds => freescale}/mpc8548cds/mpc8548cds.c   |    0
	 board/{cds => freescale}/mpc8548cds/u-boot.lds     |    4 +-
	 .../mpc8541cds => freescale/mpc8555cds}/Makefile   |    0
	 board/{cds => freescale}/mpc8555cds/config.mk      |    0
	 .../mpc8541cds => freescale/mpc8555cds}/init.S     |    0
	 board/{cds => freescale}/mpc8555cds/mpc8555cds.c   |    0
	 .../mpc8541cds => freescale/mpc8555cds}/u-boot.lds |    4 +-
	 27 files changed, 9 insertions(+), 534 deletions(-)

so it certainly makes the diffs prettier.

		Linus
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Kumar Gala had a case in the u-boot archive with multiple renames of files
with identical contents, and git would turn those into multiple "copy"
operations of one of the sources, and just deleting the other sources.

This patch makes the git exact rename detection prefer to spread out the
renames over the multiple sources, rather than do multiple copies of one
source.

NOTE! The changes are a bit larger than required, because I also renamed
the variables named "one" and "two" to "target" and "source" respectively.
That makes the logic easier to follow, especially as the "one" was
illogically the target and not the soruce, for purely historical reasons
(this piece of code used to traverse over sources and targets in the wrong
order, and when we fixed that, we didn't fix the names back then. So I
fixed them now).

The important part of this change is just the trivial score calculations
for when files have identical contents:

	/* Give higher scores to sources that haven't been used already */
	score = !source->rename_used;
	score += basename_same(source, target);

and when we have multiple choices we'll now pick the choice that gets the
best rename score, rather than only looking at whether the basename
matched.

It's worth noting a few gotchas:

 - this scoring is currently only done for the "exact match" case.

   In particular, in Kumar's example, even after this patch, the inexact
   match case is still done as a copy+delete rather than as two renames:

	 delete mode 100644 board/cds/mpc8555cds/u-boot.lds
	 copy board/{cds => freescale}/mpc8541cds/u-boot.lds (97%)
	 rename board/{cds/mpc8541cds => freescale/mpc8555cds}/u-boot.lds (97%)

   because apparently the "cds/mpc8541cds/u-boot.lds" copy looked
   a bit more similar to both end results. That said, I *suspect* we just
   have the exact same issue there - the similarity analysis just gave
   identical (or at least very _close_ to identical) similarity points,
   and we do not have any logic to prefer multiple renames over a
   copy/delete there.

   That is a separate patch.

 - When you have identical contents and identical basenames, the actual
   entry that is chosen is still picked fairly "at random" for the first
   one (but the subsequent ones will prefer entries that haven't already
   been used).

   It's not actually really random, in that it actually depends on the
   relative alphabetical order of the files (which in turn will have
   impacted the order that the entries got hashed!), so it gives
   consistent results that can be explained. But I wanted to point it out
   as an issue for when anybody actually does cross-renames.

   In Kumar's case the choice is the right one (and for a single normal
   directory rename it should always be, since the relative alphabetical
   sorting of the files will be identical), and we now get:

	 rename board/{cds => freescale}/mpc8541cds/init.S (100%)
	 rename board/{cds => freescale}/mpc8548cds/init.S (100%)

   which is the "expected" answer. However, it might still be better to
   change the pedantic "exact same basename" on/off choice into a more
   graduated "how similar are the pathnames" scoring situation, in order
   to be more likely to get the exact rename choice that people *expect*
   to see, rather than other alternatives that may *technically* be
   equally good, but are surprising to a human.

It's also unclear whether we should consider "basenames are equal" or
"have already used this as a source" to be more important. This gives them
equal weight, but I suspect we might want to just multiple the "basenames
are equal" weight by two, or something, to prefer equal basenames even if
that causes a copy/delete pair. I dunno.

Anyway, what I'm just saying in a really long-winded manner is that I
think this is right as-is, but it's not the complete solution, and it may
want some further tweaking in the future.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Occasionally, in some setups (*cough* forks on repo.or.cz *cough*) some
refs go stale, e.g. when the forkee rebased and lost some objects needed
by the fork.  The quick & dirty way to deal with those refs is to delete
them and push them again.

However, git-push first would first fetch the current commit name for the
ref, would receive a null sha1 since the ref does not point to a valid
object, then tell receive-pack that it should delete the ref with this
commit name.  delete_ref() would be subsequently be called, and check that
resolve_ref() (which does _not_ check for validity of the object) returns
the same commit name.  Which would fail.

The proper fix is to avoid corrupting repositories, but in the meantime
this is a good fix in any case.

Incidentally, some instances of "cd .." in the test cases were fixed, so
that subsequent test cases run in t/trash/ irrespective of the outcome of
the previous test cases.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Integer variables can have optional 'k', 'm' or 'g' suffix.
config_int() method will return simple decimal number, taking
care of those suffixes.
Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NAndré Goddard Rosa <andre.goddard@gmail.com>

Operations that walk directories or trees, which potentially need to
consult the .gitignore files, used to always try to open the .gitignore
file every time they entered a new directory, even when they ended up
not needing to call excluded() function to see if a path in the
directory is ignored.  This was done by push/pop exclude_per_directory()
functions that managed the data in a stack.

This changes the directory walking API to remove the need to call these
two functions.  Instead, the directory walk data structure caches the
data used by excluded() function the last time, and lazily reuses it as
much as possible.  Among the data the last check used, the ones from
deeper directories that the path we are checking is outside are
discarded, data from the common leading directories are reused, and then
the directories between the common directory and the directory the path
being checked is in are checked for .gitignore file.  This is very
similar to the way gitattributes are handled.

This API change also fixes "ls-files -c -i", which called excluded()
without setting up the gitignore data via the old push/pop functions.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Replace handcrafted reallocation with ALLOC_GROW().
Reindent "file_exists()" helper function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* maint:
  scripts: do not get confused with HEAD in work tree
  Improve description of git-branch -d and -D in man page.

When you have a file called HEAD in your work tree, many commands that
our scripts feed "HEAD" to would complain about the rev vs path
ambiguity.  A solution is to form command line more carefully by
appending -- to them, which makes it clear that we mean HEAD rev not
HEAD file.

This patch would apply to maint.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

I use "git diff" (the porcelain) really often, and am almost as often
annoyed that the completions do not know how to complete something simple
as --cached.  Now they do.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When checking out another ref, the reflogs already record from which
branch you switched.  Do that also when switching to a detached HEAD.

While at it, record also when coming _from_ a detached HEAD.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The old way of fixing warnings did not succeed on MinGW.  MinGW
does not support C99 printf format strings for size_t [1].  But
gcc on MinGW issues warnings if C99 printf format is not used.
Hence, the old stragegy to avoid warnings fails.

[1] http://www.mingw.org/MinGWiki/index.php/C99

This commits passes arguments of type size_t through a tiny
helper functions that casts to the type expected by the format
string.
Signed-off-by: NSteffen Prohaska <prohaska@zib.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This reverts commit 09fba7a5.

These tests are superseded by the ones in t5404 (added in
6fa92bf3 and 8736a848), which are more extensive and better
organized.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Some users expect that deleting a remote-tracking branch would prevent
fetch from creating it again, so be explcit about that it's not the case.
Also be a little more explicit about what fully merged means.
Signed-off-by: NJan Hudec <bulb@ucw.cz>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The helper functions 'map' and 'skip_commit' were provided to commit
filters by sourcing filter-branch itself.  This was done with a certain
environment variable set to indicate that only the functions should be
defined, and the script should return then.

This was really hacky, and it did not work all that well, since the
full path to git-filter-branch was not known at all times.

Avoid that by putting the functions into a variable, and eval'ing
that variable.  The commit filter gets these functions by prepending
the variable to the specified commands.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When colors are set to "true" on the repository, the git log output
will contain control characters to set/reset the colors, even when
the output is to a pipe. This makes list_stash() fail as the
downstream sed does not see what it is expecting.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Using the helper function to test for absolute paths makes porting easier.
Signed-off-by: NSteffen Prohaska <prohaska@zib.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NWincent Colaiuta <win@wincent.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* maint:
  user-manual: recovering from corruption
  user-manual: clarify language about "modifying" old commits
  user-manual: failed push to public repository
  user-manual: define "branch" and "working tree" at start
  git-checkout: describe detached head correctly

* 'maint' of git://linux-nfs.org/~bfields/git:
  user-manual: recovering from corruption
  user-manual: clarify language about "modifying" old commits
  user-manual: failed push to public repository
  user-manual: define "branch" and "working tree" at start

Some instructions on dealing with corruption of the object database.

Most of this text is from an example by Linus, identified by Nicolas
Pitre <nico@cam.org> with a little further editing by me.
Signed-off-by: N"J. Bruce Fields" <bfields@citi.umich.edu>

When we fail to open a temporary file to be renamed to something else,
we reported the final filename, not the temporary file we failed to
open.
Signed-off-by: NAndré Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's important to remember that git doesn't really allowing "editing" or
"modifying" commits, only replacing them by new commits.  Redo some of
the language to make this clearer.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

When you cherry-pick or revert a commit, naming it with an annotated
tag, we added a comment, attempting to repeat what we got from the end
user, to the message.

But this was inconsistent.  When we got "cherry-pick branch", we
recorded the object name (40-letter SHA-1) without saying anything like
"original was 'branch'".  There was no need to.  Also recent rewrite to
use parse-options made it impossible to parrot the original command line
without "unparsing".

This removes the code that implements the misguided "we dereferenced the
tag so record that in the commit message" behaviour.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

More details on the case of a failed push to a public (non-shared)
repository.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

Some explanation here might help.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

When you have a file called HEAD in the work tree, the code to report
where the HEAD is at when "git checkout $commit^0" is done triggered
unnecessary ambiguity checking.

Explicitly mark the command line with "--" and make it clear that we are
talking about a revision.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* maint:
  Fix rev-list when showing objects involving submodules
  test format-patch -s: make sure MIME content type is shown as needed
  format-patch -s: add MIME encoding header if signer's name requires so

* rv/maint-index-commit:
  Make GIT_INDEX_FILE apply to git-commit

* lt/maint-rev-list-gitlink:
  Fix rev-list when showing objects involving submodules

* jc/maint-add-sync-stat:
  t2200: test more cases of "add -u"
  git-add: make the entry stat-clean after re-adding the same contents
  ce_match_stat, run_diff_files: use symbolic constants for readability

* jc/maint-format-patch-encoding:
  test format-patch -s: make sure MIME content type is shown as needed
  format-patch -s: add MIME encoding header if signer's name requires so

* bs/maint-t7005:
  t7005-editor.sh: Don't invoke real vi when it is in GIT_EXEC_PATH

* bs/maint-commit-options:
  git-commit: Add tests for invalid usage of -a/--interactive with paths
  git-commit.sh: Fix usage checks regarding paths given when they do not make sense

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Earlier a6080a0a (War on whitespace)
dropped a necessary trailing whitespace from the test vector.

* jk/send-pack: (24 commits)
  send-pack: cluster ref status reporting
  send-pack: fix "everything up-to-date" message
  send-pack: tighten remote error reporting
  make "find_ref_by_name" a public function
  Fix warning about bitfield in struct ref
  send-pack: assign remote errors to each ref
  send-pack: check ref->status before updating tracking refs
  send-pack: track errors for each ref
  git-push: add documentation for the newly added --mirror mode
  Add tests for git push'es mirror mode
  Update the tracking references only if they were succesfully updated on remote
  Add a test checking if send-pack updated local tracking branches correctly
  git-push: plumb in --mirror mode
  Teach send-pack a mirror mode
  send-pack: segfault fix on forced push
  Reteach builtin-ls-remote to understand remotes
  send-pack: require --verbose to show update of tracking refs
  receive-pack: don't mention successful updates
  more terse push output
  Build in ls-remote
  ...

* sb/clean:
  Teach git clean to use setup_standard_excludes()
  git-clean: Fix error message if clean.requireForce is not set.
  Make git-clean a builtin

* js/mingw-fallouts:
  fetch-pack: Prepare for a side-band demultiplexer in a thread.
  rehabilitate some t5302 tests on 32-bit off_t machines
  Allow ETC_GITCONFIG to be a relative path.
  Introduce git_etc_gitconfig() that encapsulates access of ETC_GITCONFIG.
  Allow a relative builtin template directory.
  Close files opened by lock_file() before unlinking.
  builtin run_command: do not exit with -1.
  Move #include <sys/select.h> and <sys/ioctl.h> to git-compat-util.h.
  Use is_absolute_path() in sha1_file.c.
  Skip t3902-quoted.sh if the file system does not support funny names.
  t5302-pack-index: Skip tests of 64-bit offsets if necessary.
  t7501-commit.sh: Not all seds understand option -i
  t5300-pack-object.sh: Split the big verify-pack test into smaller parts.