When receiving a push, we advertise ref tips from any
alternate repositories, in case that helps the client send a
smaller pack. Since these refs don't actually exist in the
destination repository, we don't transmit the real ref
names, but instead use the pseudo-ref ".have".

If your alternate has a large number of duplicate refs (for
example, because it is aggregating objects from many related
repositories, some of which will have the same tags and
branch tips), then we will send each ".have $sha1" line
multiple times. This is a pointless waste of bandwidth, as
we are simply repeating the same fact to the client over and
over.

This patch eliminates duplicate .have refs early on. It does
so efficiently by sorting the complete list and skipping
duplicates. This has the side effect of re-ordering the
.have lines by ascending sha1; this isn't a problem, though,
as the original order was meaningless.

There is a similar .have system in fetch-pack, but it
does not suffer from the same problem. For each alternate
ref we consider in fetch-pack, we actually open the object
and mark it with the SEEN flag, so duplicates are
automatically culled.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The foreach_alt_odb function triggers a callback for each
alternate object db we have, with room for a single void
pointer as data. Currently, we always call refs_from_alternate_cb
as the callback function, and then pass another callback (to
receive each ref individually) as the void pointer.

This has two problems:

  1. C technically forbids stuffing a function pointer into
     a "void *". In practice, this probably doesn't matter
     on any architectures git runs on, but it never hurts to
     follow the letter of the law.

  2. There is no room for an extra data pointer. Indeed, the
     alternate_ref_fn that refs_from_alternate_cb calls
     takes a void* for data, but we always pass it NULL.

Instead, let's properly stuff our function pointer into a
data struct, which also leaves room for an extra
caller-supplied data pointer. And to keep things simple for
existing callers, let's make a for_each_alternate_ref
function that takes care of creating the extra struct.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

 * load_file() returns a void pointer but is using 0 for the return
   value

 * builtin/receive-pack.c forgot to include builtin.h

 * packet_trace_prefix can be marked static

 * ll_merge takes a pointer for its last argument, not an int

 * crc32 expects a pointer as the second argument but Z_NULL is defined
   to be 0 (see 38f4d138 sparse fix: Using plain integer as NULL pointer,
   2006-11-18 for more info)
Signed-off-by: NStephen Boyd <bebarino@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The receiving end of "git push" advertises the objects that the repository
itself does not use, but are at the tips of refs in other repositories
whose object databases are used as alternates for it. This helps it avoid
having to receive (and the pusher having to send) objects that are already
available to the receiving repository via the alternates mechanism.

Tweak the helper function that implements this feature, and move it to
transport.[ch] for future reuse by other programs.

The additional test demonstrates how this optimization is helping "git push",
and "git fetch" is ignorant about it.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Acked-by: NShawn O. Pearce <spearce@spearce.org>

Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.

The function calls have been replaced 1-to-1 in their usage.
Signed-off-by: NCarlos Martín Nieto <cmn@elego.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This shows a trace of all packets coming in or out of a given
program. This can help with debugging object negotiation or
other protocol issues.

To keep the code changes simple, we operate at the lowest
level, meaning we don't necessarily understand what's in the
packets. The one exception is a packet starting with "PACK",
which causes us to skip that packet and turn off tracing
(since the gigantic pack data will not be interesting to
read, at least not in the trace format).

We show both written and read packets. In the local case,
this may mean you will see packets twice (written by the
sender and read by the receiver). However, for cases where
the other end is remote, this allows you to see the full
conversation.

Packet tracing can be enabled with GIT_TRACE_PACKET=<foo>,
where <foo> takes the same arguments as GIT_TRACE.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Acked-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NThiago Farina <tfransosi@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Update the definition and callers of string_list_append to use the
string_list as the first argument.  This helps make the string_list
API easier to use by being more consistent.
Signed-off-by: NJulian Phillips <julian@quantumfyre.co.uk>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Update the definition and callers of string_list_lookup to use the
string_list as the first argument.  This helps make the string_list
API easier to use by being more consistent.
Signed-off-by: NJulian Phillips <julian@quantumfyre.co.uk>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Without this patch at least IBM VisualAge C 5.0 (I have 5.0.2) on AIX
5.1 fails to compile git.

enum style is inconsistent already, with some enums declared on one
line, some over 3 lines with the enum values all on the middle line,
sometimes with 1 enum value per line... and independently of that the
trailing comma is sometimes present and other times absent, often
mixing with/without trailing comma styles in a single file, and
sometimes in consecutive enum declarations.

Clearly, omitting the comma is the more portable style, and this patch
changes all enum declarations to use the portable omitted dangling
comma style consistently.
Signed-off-by: NGary V. Vaughan <gary@thewrittenword.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This shrinks the top-level directory a bit, and makes it much more
pleasant to use auto-completion on the thing. Instead of

	[torvalds@nehalem git]$ em buil<tab>
	Display all 180 possibilities? (y or n)
	[torvalds@nehalem git]$ em builtin-sh
	builtin-shortlog.c     builtin-show-branch.c  builtin-show-ref.c
	builtin-shortlog.o     builtin-show-branch.o  builtin-show-ref.o
	[torvalds@nehalem git]$ em builtin-shor<tab>
	builtin-shortlog.c  builtin-shortlog.o
	[torvalds@nehalem git]$ em builtin-shortlog.c

you get

	[torvalds@nehalem git]$ em buil<tab>		[type]
	builtin/   builtin.h
	[torvalds@nehalem git]$ em builtin		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/sh<tab>	[type]
	shortlog.c     shortlog.o     show-branch.c  show-branch.o  show-ref.c     show-ref.o
	[torvalds@nehalem git]$ em builtin/sho		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/shor<tab>	[type]
	shortlog.c  shortlog.o
	[torvalds@nehalem git]$ em builtin/shortlog.c

which doesn't seem all that different, but not having that annoying
break in "Display all 180 possibilities?" is quite a relief.

NOTE! If you do this in a clean tree (no object files etc), or using an
editor that has auto-completion rules that ignores '*.o' files, you
won't see that annoying 'Display all 180 possibilities?' message - it
will just show the choices instead.  I think bash has some cut-off
around 100 choices or something.

So the reason I see this is that I'm using an odd editory, and thus
don't have the rules to cut down on auto-completion.  But you can
simulate that by using 'ls' instead, or something similar.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the client has requested side-band-64k capability, send any
of the internal error or warning messages in the muxed side-band
stream using the same band as our hook output, band #2.  By putting
everything in one stream we ensure all messages are processed by
the side-band demuxer, avoiding interleaving between our own stderr
and the side-band demuxer's stderr buffers.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the client requests to enable side-band-64k capability we can
safely send any hook stdout or stderr data down side band #2,
so the client can present it to the user.

If side-band-64k isn't enabled, hooks continue to inherit stderr
from the parent receive-pack process.

When the side band channel is being used the push client will wind up
prefixing all server messages with "remote: ", just like fetch does,
so our test vector has to be updated with the new expected output.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the client requests the side-band-64k protocol capability we
now wrap the status report data inside of packets sent to band #1.
This permits us to later send additional progress or informational
messages down band #2.

If side-band-64k was enabled, we always send a final flush packet
to let the client know we are done transmitting.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Moving capability advertisement into the packet_write call itself
makes it easier to add additional capabilities to the list, be
it optional by configuration, or always present in the protocol.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When --stateless-rpc is passed as a command line parameter to
upload-pack or receive-pack the programs now assume they may
perform only a single read-write cycle with stdin and stdout.
This fits with the HTTP POST request processing model where a
program may read the request, write a response, and must exit.

When --advertise-refs is passed as a command line parameter only
the initial ref advertisement is output, and the program exits
immediately.  This fits with the HTTP GET request model, where
no request content is received but a response must be produced.

HTTP headers and/or environment are not processed here, but
instead are assumed to be handled by the program invoking
either service backend.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's a compound word.
Signed-off-by: NFelipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Introduce two new configuration variables, receive.autogc (defaults to
true) and receive.updateserverinfo (defaults to false).  When these are
set, receive-pack runs "gc --auto --quiet" and "update-server-info"
respectively after it finishes receiving data from "git push" and updating
refs.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Acked-by: NNicolas Pitre <nico@fluxnic.net>

This makes git-push refuse deleting the current branch by default.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This makes git-push refuse pushing into a non-bare repository to update
the current branch by default.  To help people who are used to be able to
do this (and later "reset --hard" it in some other way), an error message
is issued when this refusal is triggered, instructing how to resurrect the
old behaviour.

Hosting sites that do not give the users direct access to customize their
repositories (e.g. repo.or.cz, gitorious, github etc.) may further want to
explicitly set the configuration variable to "refuse" for their customers'
repositories.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The function run_status was used to report failures after a hook was run.
By now, the only thing that the function itself reported was the exit code
of the hook (if it was non-zero). But this is redundant because it can be
expected that the hook itself will have reported a suitable error.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In the case where a program was not found, it was still the task of the
caller to report an error to the user. Usually, this is an interesting case
but only few callers actually reported a specific error (though many call
sites report a generic error message regardless of the cause).

With this change the error is reported by run_command, but since there is
one call site in git.c that does not want that, an option is added to
struct child_process, which is used to turn the error off.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The motivation for this change is that system call failures are serious
errors that should be reported to the user, but only few callers took the
burden to decode the error codes that the functions returned into error
messages.

If at all, then only an unspecific error message was given. A prominent
example is this:

   $ git upload-pack . | :
   fatal: unable to run 'git-upload-pack'

In this example, git-upload-pack, the external command invoked through the
git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to
report the real cause. In fact, this very error message is copied to the
syslog if git-daemon's client aborts the connection early.

With this change, system call failures are reported immediately after the
failure and only a generic failure code is returned to the caller. In the
above example the error is now to the point:

   $ git upload-pack . | :
   error: git-upload-pack died of signal

Note that there is no error report if the invoked program terminated with
a non-zero exit code, because it is reasonable to expect that the invoked
program has already reported an error. (But many run_command call sites
nevertheless write a generic error message.)

There was one special return code that was used to identify the case where
run_command failed because the requested program could not be exec'd. This
special case is now treated like a system call failure with errno set to
ENOENT. No error is reported in this case, because the call site in git.c
expects this as a normal result. Therefore, the callers that carefully
decoded the return value still check for this condition.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As a general guideline, functions in git's code return zero to indicate
success and negative values to indicate failure. The run_command family of
functions followed this guideline. But there are actually two different
kinds of failure:

- failures of system calls;

- non-zero exit code of the program that was run.

Usually, a non-zero exit code of the program is a failure and means a
failure to the caller. Except that sometimes it does not. For example, the
exit code of merge programs (e.g. external merge drivers) conveys
information about how the merge failed, and not all exit calls are
actually failures.

Furthermore, the return value of run_command is sometimes used as exit
code by the caller.

This change arranges that the exit code of the program is returned as a
positive value, which can now be regarded as the "result" of the function.
System call failures continue to be reported as negative values.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the objects that a client pushes to the server cannot be processed for
any reason, an error is reported back to the client via the git protocol.
We used to send quite detailed information if a system call failed if
unpack-objects is run. This can be regarded as an information leak. Now we
do not send any error details like we already do in the case where
index-pack failed.

Errors in system calls as well as the exit code of unpack-objects and
index-pack are now reported to stderr; in the case of a local push or via
ssh these messages still go to the client, but that is OK since these forms
of access to the server assume that the client can be trusted. If
receive-pack is run from git-daemon, then the daemon should put the error
messages into the syslog.

With this reasoning a new status report is added for the post-update-hook;
untrusted (i.e. daemon's) clients cannot observe its status anyway, others
may want to know failure details.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The fetching of OFS_DELTA objects has been negotiated between both peers
since git version 1.4.4.  However, this was missing from the push side
where every OFS_DELTA objects were always converted to REF_DELTA objects
causing an increase in transferred data.

To fix this, both the client and the server processes have to be
modified: the former to invoke pack-objects with --delta-base-offset
when the server provides the ofs-delta capability, and the later to send
that capability when OFS_DELTA objects are allowed as already indicated
by the repack.usedeltabaseoffset config variable which is TRUE by
default since git v1.6.0.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This helps to notice when something's going wrong, especially on
systems which lock open files.

I used the following criteria when selecting the code for replacement:
- it was already printing a warning for the unlink failures
- it is in a function which already printing something or is
  called from such a function
- it is in a static function, returning void and the function is only
  called from a builtin main function (cmd_)
- it is in a function which handles emergency exit (signal handlers)
- it is in a function which is obvously cleaning up the lockfiles
Signed-off-by: NAlex Riesen <raa.lkml@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Certain remote commands, when asked to do something in a
particular directory that was not actually a git repository,
would say "unable to chdir or not a git archive". The
"chdir" bit is an unnecessary detail, and the term "git
archive" is much less common these days than "git repository".

So let's switch them all to:

  fatal: '%s' does not appear to be a git repository
Signed-off-by: NJeff King <peff@peff.net>
Acked-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

While all of the strings passed to warning() are, in fact, literals, the
compiler doesn't recognize them as such because it doesn't see through
the loop used to iterate over them:

   builtin-receive-pack.c: In function 'warn_unconfigured_deny':
   builtin-receive-pack.c:247: warning: format not a string literal and no format arguments
   builtin-receive-pack.c: In function 'warn_unconfigured_deny_delete_current':
   builtin-receive-pack.c:273: warning: format not a string literal and no format arguments

Calm the compiler by adding easily recognizable format string literals.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

This is a companion patch to the recent 3d95d92b (receive-pack: explain
what to do when push updates the current branch, 2009-01-31).

Deleting the current branch from a remote will result in the next clone
from it not check out anything, among other things.  It also is one of the
cause that makes remotes/origin/HEAD a dangling symbolic ref.  This patch
still allows the traditional behaviour but with a big warning, and promises
that the default will change to 'refuse' in a future release.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NAlexander Potashev <aspotashev@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This makes "git push" issue a more detailed instruction when a user pushes
into the current branch of a non-bare repository without having an
explicit configuration set to receive.denycurrentbranch.  In such a case,
it will also tell the user that the default will change to refusal in a
future version of git.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A function that runs a hook is used in several Git commands.
builtin-commit.c has the one that is most general for cases without
piping. The one in builtin-gc.c prints some useful warnings.
This patch moves a merged version of these variants into libgit and
lets the other builtins use this libified run_hook().

The run_hook() function used in receive-pack.c feeds the standard
input of the pre-receive or post-receive hooks. This function is
renamed to run_receive_hook() because the libified run_hook() cannot
handle this.
Mentored-by: NDaniel Barkalow <barkalow@iabervon.org>
Mentored-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NStephan Beyer <s-beyer@gmx.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Pushing into the currently checked out branch of a non-bare
repository can be dangerous; the HEAD then loses sync with
the index and working tree, and it looks in the receiving
repo as if the pushed changes have been reverted in the
index (since they were never there in the first place).

This patch adds a safety valve that checks for this
condition and either generates a warning or denies the
update. We trigger the check only on a non-bare repository,
since a bare repo does not have a working tree (and in fact,
pushing to the HEAD branch is a common workflow for
publishing repositories).

The behavior is configurable via receive.denyCurrentBranch,
defaulting to "warn" so as not to break existing setups
(though it may, after a deprecation period, switch to
"refuse" by default). For users who know what they are doing
and want to silence the warning (e.g., because they have a
post-receive hook that reconciles the HEAD and working
tree), they can turn off the warning by setting it to false
or "ignore".
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Occasionally, it may be useful to prevent branches from getting deleted from
a centralized repository, particularly when no administrative access to the
server is available to undo it via reflog. It also makes
receive.denyNonFastForwards more useful if it is used for access control
since it prevents force-updating by deleting and re-creating a ref.
Signed-off-by: NJan Krüger <jk@jk.gs>
Acked-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In the alternate_object_database structure, ent->base[] is a buffer the
users can use to form pathnames to loose objects, and ent->name is a
pointer into that buffer (it points at one beyond ".git/objects/").  If
you get a call to add_refs_from_alternate() after somebody used the entry
(has_loose_object() has been called, for example), *ent->name would not be
NUL, and ent->base[] won't be the path to the object store.

This caller is expecting to read the path to the object store in ent->base[];
it needs to NUL terminate the buffer if it wants to.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Earlier, when pushing into a repository that borrows from alternate object
stores, we followed the longstanding design decision not to trust refs in
the alternate repository that houses the object store we are borrowing
from.  If your public repository is borrowing from Linus's public
repository, you pushed into it long time ago, and now when you try to push
your updated history that is in sync with more recent history from Linus,
you will end up sending not just your own development, but also the
changes you acquired through Linus's tree, even though the objects needed
for the latter already exists at the receiving end.  This is because the
receiving end does not advertise that the objects only reachable from the
borrowed repository (i.e. Linus's) are already available there.

This solves the issue by making the receiving end advertise refs from
borrowed repositories.  They are not sent with their true names but with a
phoney name ".have" to make sure that the old senders will safely ignore
them (otherwise, the old senders will misbehave, trying to push matching
refs, and mirror push that deletes refs that only exist at the receiving
end).
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It is a good thing to do in general, but more importantly, transport
routines can only be used by built-ins, which is what I'll be adding next.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>