pack-objects: shrink struct object_entry

Turn some boolean fields into bitfields and use uint32_t for name
hash.  This shrinks the size of the structure from 128 bytes to 120
bytes.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4030: demonstrate behavior of show with textconv

"git show <commit>" honors the --textconv option while "git show <blob>"
does not. Demonstrate this in the test.

Since the current behavior is supposed to stay as is, we expect the
default for "git show <blob>" to remain --no-textconv.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff_opt: track whether flags have been set explicitly

The diff_opt infrastructure sets flags based on defaults and command
line options.  It is impossible to tell whether a flag has been set
as a default or on explicit request.  Update the structure so that
this detection is possible:

 * Add an extra "opt->touched_flags" that keeps track of all the
   fields that have been touched by DIFF_OPT_SET and DIFF_OPT_CLR.

 * You may continue setting the default values to the flags, like
   commands in the "log" family do in cmd_log_init_defaults(), but
   after you finished setting the defaults, you clear the
   touched_flags field;

 * And then you let the usual callchain call diff_opt_parse(),
   allowing the opt->flags be set or unset, while keeping track of
   which bits the user touched;

 * There is an optional callback "opt->set_default" that is called
   at the very beginning to let you inspect touched_flags and update
   opt->flags appropriately, before the remainder of the diffcore
   machinery is set up, taking the opt->flags value into account.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
show: honor --textconv for blobs

Currently, "diff" and "cat-file" for blobs honor "--textconv" options
(with the former defaulting to "--textconv" and the latter to
"--no-textconv") whereas "show" does not honor this option, even though
it takes diff options.

Make "show" on blobs honor "--textconv" when it is asked.  The default
is not to apply textconv, which is in line with what "cat-file" does.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cat-file: do not die on --textconv without textconv filters

When a command is supposed to use textconv filters (by default or with
"--textconv") and none are configured then the blob is output without
conversion; the only exception to this rule is "cat-file --textconv".

Make it behave like the rest of textconv aware commands.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t7008: demonstrate behavior of grep with textconv

Currently, "git grep" does not honor any textconv filters, with nor
without --textconv. Demonstrate this in the tests.

The default is expected to remain unchanged.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep: allow to use textconv filters

Recently and not so recently, we made sure that log/grep type operations
use textconv filters when a userfacing diff would do the same:

ef90ab6 (pickaxe: use textconv for -S counting, 2012-10-28)
b1c2f57 (diff_grep: use textconv buffers for add/deleted files, 2012-10-28)
0508fe5 (combine-diff: respect textconv attributes, 2011-05-23)

"git grep" currently does not use textconv filters at all, that is
neither for displaying the match and context nor for the actual grepping,
even when requested by --textconv.

Introduce an option "--textconv" which makes git grep use any configured
textconv filters for grepping and output purposes. It is off by default.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
grep: honor --textconv for the case rev:path

Make "grep" honor the "--textconv" option also for the object case, i.e.
when used with an argument "rev:path".

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup_reflog_action: document the rules for using GIT_REFLOG_ACTION

The set_reflog_action helper (in git-sh-setup) is designed to be
used once at the very top of a program, like this in "git am", for
example:

	set_reflog_action am

The helper function sets the given string to GIT_REFLOG_ACTION only
when GIT_REFLOG_ACTION is not yet set.  Thanks to this, "git am",
when run as the top-level program, will use "am" in GIT_REFLOG_ACTION
and the reflog entries made by whatever it does will record the
updates of refs done by "am".

Because of the conditional assignment, when "git am" is run as a
subprogram (i.e. an implementation detail) of "git rebase" that
already sets GIT_REFLOG_ACTION to its own name, the call in "git am"
to the helper function at the beginning will *not* have any effect.

So "git rebase" can do this:

	set_reflog_action rebase
	... do its own preparation, like checking out "onto" commit
        ... decide to do "format-patch" to "am" pipeline
        	git format-patch --stdout >mbox
		git am mbox

and the reflog entries made inside "git am" invocation will say
"rebase", not "am".

Calls to "git" commands that update refs would use GIT_REFLOG_ACTION
to record who did that update.  Most such calls in scripted Porcelains
do not define custom reflog message and rely on GIT_REFLOG_ACTION to
contain its (or its caller's, when it is called as a subprogram) name.

If a scripted Porcelain wants to record a custom reflog message for
a single invocation of "git" command (e.g. when "git rebase" uses
"git checkout" to detach HEAD at the commit a series is to be
replayed on), it needs to set GIT_REFLOG_ACTION to the custom
message and export it while calling the "git" command, but such an
assignment must be restricted to that single "git" invocation and
should not be left behind to affect later codepath.

Document the rules to avoid future confusion.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
git p4 test: sanitize P4CHARSET

In the tests, p4d is started without using "internationalized
mode".  Make sure this environment variable is unset, otherwise
a mis-matched user setting would break the tests.  The error
message would be "Unicode clients require a unicode enabled server."

[pw: use unset, add commit text]

Signed-off-by: Kazuki Saitoh <ksaitoh560@gmail.com>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
move setup_alternate_shallow and write_shallow_commits to shallow.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test-sha1: add a binary output mode

The test-sha1 helper program will run our internal sha1
routines over its input and output the 40-byte hex sha1.
Sometimes, however, it is useful to have the binary 20-byte
sha1 (and it's a pain to convert back in the shell). Let's
add a "-b" option to output the binary version.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sha1-lookup: handle duplicate keys with GIT_USE_LOOKUP

The sha1_entry_pos function tries to be smart about
selecting the middle of a range for its binary search by
looking at the value differences between the "lo" and "hi"
constraints. However, it is unable to cope with entries with
duplicate keys in the sorted list.

We may hit a point in the search where both our "lo" and
"hi" point to the same key. In this case, the range of
values between our endpoints is 0, and trying to scale the
difference between our key and the endpoints over that range
is undefined (i.e., divide by zero). The current code
catches this with an "assert(lov < hiv)".

Moreover, after seeing that the first 20 byte of the key are
the same, we will try to establish a value from the 21st
byte. Which is nonsensical.

Instead, we can detect the case that we are in a run of
duplicates, and simply do a final comparison against any one
of them (since they are all the same, it does not matter
which). If the keys match, we have found our entry (or one
of them, anyway).  If not, then we know that we do not need
to look further, as we must be in a run of the duplicate
key.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
add tests for indexing packs with delta cycles

If we receive a broken or malicious pack from a remote, we
will feed it to index-pack. As index-pack processes the
objects as a stream, reconstructing and hashing each object
to get its name, it is not very susceptible to doing the
wrong with bad data (it simply notices that the data is
bogus and aborts).

However, one question raised on the list is whether it could
be susceptible to problems during the delta-resolution
phase. In particular, can a cycle in the packfile deltas
cause us to go into an infinite loop or cause any other
problem?

The answer is no.

We cannot have a cycle of delta-base offsets, because they
go only in one direction (the OFS_DELTA object mentions its
base by an offset towards the beginning of the file, and we
explicitly reject negative offsets).

We can have a cycle of REF_DELTA objects, which refer to
base objects by sha1 name. However, index-pack does not know
these sha1 names ahead of time; it has to reconstruct the
objects to get their names, and it cannot do so if there is
a delta cycle (in other words, it does not even realize
there is a cycle, but only that there are items that cannot
be resolved).

Even though we can reason out that index-pack should handle
this fine, let's add a few tests to make sure it behaves
correctly.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
test index-pack on packs with recoverable delta cycles

The previous commit added tests to show that index-pack
correctly bails in unrecoverable situations. There are some
situations where the data could be recovered, but it is not
currently:

  1. If we can break the cycle using an object from another
     pack via --fix-thin.

  2. If we can break the cycle using a duplicate of one of
     the objects found in the same pack.

Note that neither of these is particularly high priority; a
delta cycle within a pack should never occur, and we have no
record of even a buggy git implementation creating such a
pack.

However, it's worth adding these tests for two reasons. One,
to document that we do not currently handle the situation,
even though it is possible. And two, to exercise the code
that runs in this situation; even though it fails, by
running it we can confirm that index-pack detects the
situation and aborts, and does not misbehave (e.g., by
following the cycle in an infinite loop).

In both cases, we hit an assert that aborts index-pack.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: report invalid tracking branch as gone

Command "git branch -vv" will report tracking branches, but invalid
tracking branches are also reported. This is because the function
stat_tracking_info() can not distinguish invalid tracking branch
from other cases which it would not like to report, such as
there is no upstream settings at all, or nothing is changed between
one branch and its upstream.

Junio suggested missing upstream should be reported [1] like:

    $ git branch -v -v
      master    e67ac84 initial
    * topic     3fc0f2a [topicbase: gone] topic

    $ git status
    # On branch topic
    # Your branch is based on 'topicbase', but the upstream is gone.
    #   (use "git branch --unset-upstream" to fixup)
    ...

    $ git status -b -s
    ## topic...topicbase [gone]
    ...

In order to do like that, we need to distinguish these three cases
(i.e. no tracking, with configured but no longer valid tracking, and
with tracking) in function stat_tracking_info(). So the refactored
function stat_tracking_info() has three return values: -1 (with "gone"
base), 0 (no base), and 1 (with base).

If the caller does not like to report tracking info when nothing
changed between the branch and its upstream, simply checks if
num_theirs and num_ours are both 0.

[1]: http://thread.gmane.org/gmane.comp.version-control.git/231830/focus=232288

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
status: always show tracking branch even no change

In order to see what the current branch is tracking, one way is using
"git branch -v -v", but branches other than the current are also
reported. Another way is using "git status", such as:

    $ git status
    # On branch master
    # Your branch is ahead of 'origin/master' by 1 commit.
    ...

But this will not work if there is no change between the current
branch and its upstream. Always report upstream tracking info
even if there is no difference, so that "git status" is consistent
for checking tracking info for current branch. E.g.

    $ git status
    # On branch feature1
    # Your branch is up-to-date with 'github/feature1'.
    ...

    $ git status -bs
    ## feature1...github/feature1
    ...

    $ git checkout feature1
    Already on 'feature1'
    Your branch is up-to-date with 'github/feature1'.
    ...

Also add some test cases in t6040.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
shallow: only add shallow graft points to new shallow file

for_each_commit_graft() goes through all graft points, and shallow
boundaries are just one special kind of grafting.

If $GIT_DIR/shallow and $GIT_DIR/info/grafts are both present,
write_shallow_commits() may catch both sets, accidentally turning
some graft points to shallow boundaries.  Don't do that.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
shallow: add setup_temporary_shallow()

This function is like setup_alternate_shallow() except that it does
not lock $GIT_DIR/shallow.  It is supposed to be used when a program
generates temporary shallow for use by another program, then throw
the shallow file away.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
upload-pack: delegate rev walking in shallow fetch to pack-objects

upload-pack has a special revision walking code for shallow
recipients. It works almost like the similar code in pack-objects
except:

1. in upload-pack, graft points could be added for deepening;

2. also when the repository is deepened, the shallow point will be
   moved further away from the tip, but the old shallow point will be
   marked as edge to produce more efficient packs. See 6523078 (make
   shallow repository deepening more network efficient - 2009-09-03).

Pass the file to pack-objects via --shallow-file. This will override
$GIT_DIR/shallow and give pack-objects the exact repository shape
that upload-pack has.

mark edge commits by revision command arguments. Even if old shallow
points are passed as "--not" revisions as in this patch, they will not
be picked up by mark_edges_uninteresting() because this function looks
up to parents for edges, while in this case the edge is the children,
in the opposite direction. This will be fixed in an later patch when
all given uninteresting commits are marked as edges.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>