One caller of deref_tag() was not careful enough to make sure
what deref_tag() returned was not NULL (i.e. we found a tag
object that points at an object we do not have).  Fix it, and
warn about refs that point at such an incomplete tag where
needed.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This implements three things (trying very hard to be backwards
compatible):

It sends the "multi_ack" capability via the mechanism proposed by
Sergey Vlasov.

When the client sends "multi_ack" with at least one "want", multi_ack
is enabled.

When multi_ack is enabled, "continue" is appended to each "ACK" until
either the server can not store more refs, or "done" is received.

In contrast to the original protocol, as long as "continue" is sent,
flushes are answered by a "NAK" (not just until an "ACK" was sent),
and if "continue" was sent at least once, the last message is an
"ACK" without "continue".
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This patch is based on Junio's proposal. It marks parents of common revs
so that they do not clutter up the has_sha1 array.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

upload-pack would set create_full_pack=1 if nr_has==0, but would ask later
if nr_needs<MAX_NEEDS. If that proves true, it would ignore create_full_pack,
and arguments would be written into unreserved memory.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This makes sure what the other end asks for are among what we
offered to give them.  Otherwise we would end up running
git-rev-list with 20-byte nonsense, only to find it either die
(because the object was not found) or waste time (because we
ended up serving that phony 'client').

Also avoid wasting needs_sha1 pool to record duplicates, and
detect cloning requests better.

[this used to be on top of Johannes fetch-pack enhancements,
 which we are rewinding it for further testing for now, so
 the commit is rebased.]
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Let's have it simmer a bit longer in the proposed updates branch
and shake the problems out.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The code to check if we have the object the other side has was bogus
(my fault).
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The current fetch/upload protocol works like this:

- client sends revs it wants to have via "want" messages
- client sends a flush message (message with len 0)
- client sends revs it has via "have" messages
- after one window (32 revs), a flush is sent
- after each subsequent window, a flush is sent, and an ACK/NAK is received.
        (NAK means that server does not have any of the transmitted revs;
         ACK sends also the sha1 of the rev server has)
 - when the first ACK is received, client sends "done", and does not expect
        any further messages

One special case, though:

- if no ACK is received (only NAK's), and client runs out of revs to send,
        "done" is sent, and server sends just one more "NAK"

A smarter scheme, which actually has a chance to detect more than one
common rev, would be to send more than just one ACK. This patch implements
the server side of the following extension to the protocol:

- client sends at least one "want" message with "multi_ack" appended, like

        "want 1234567890123456789012345678901234567890 multi_ack"

- if the server understands that extension, it will send ACK messages for all
        revs it has, not just the first one

- server appends "continue" to the ACK messages like

        "ACK 1234567890123456789012345678901234567890 continue"

        until it has MAX_HAS-1 revs. In this manner, client knows when to
        stop sending revs by checking for the substring "continue" (and
        further knows that server understands multi_ack)

In this manner, the protocol stays backwards compatible, since both client
must send "want ... multi_ack" and server must answer with "ACK ...
continue" to enable the extension.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This patch is based on Junio's proposal. It marks parents of common revs
so that they do not clutter up the has_sha1 array.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Later round would further improve fetch-pack not to send useless "have",
but in the meantime, increase it to help upload-pack to find more common
commits, as discussed on the list.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

It turns out that not only did git-daemon do DWIM, but git-upload-pack
does as well.  This is bad; security checks have to be performed *after*
canonicalization, not before.

Additionally, the current git-daemon can be trivially DoSed by spewing
SYNs at the target port.

This patch adds a --strict option to git-upload-pack to disable all
DWIM, a --timeout option to git-daemon and git-upload-pack, and an
--init-timeout option to git-daemon (which is typically set to a much
lower value, since the initial request should come immediately from the
client.)
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This updates git-ls-remote to show SHA1 names of objects that are
referred by tags, in the "ref^{}" notation.

This would make git-findtags (without -t flag) almost trivial.

    git-peek-remote . |
    sed -ne "s:^$target	"'refs/tags/\(.*\)^{}$:\1:p'

Also Pasky could do:

    git-ls-remote --tags $remote |
    sed -ne 's:\(	refs/tags/.*\)^{}$:\1:p'

to find out what object each of the remote tags refers to, and
if he has one locally, run "git-fetch $remote tag $tagname" to
automatically catch up with the upstream tags.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Cloning from a repository with more than 256 refs (heads and tags
included) will choke, because upload-pack has a built-in limit of
feeding not more than MAX_NEEDS (currently 256) heads to underlying
git-rev-list.  This is a problem when cloning a repository with many
tags, like http://www.linux-mips.org/pub/scm/linux.git, which has 290+
tags.

This commit introduces a new flag, --all, to git-rev-list, to include
all refs in the repository.  Updated upload-pack detects requests that
ask more than MAX_NEEDS refs, and sends everything back instead.

We may probably want to tweak the definitions of MAX_NEEDS and
MAX_HAS, but that is a separate topic.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Solaris 8 doesn't have the newer unsetenv() and setenv()
functions, so replace them with putenv().  The one use of
unsetenv() in fsck-cache.c now sets GIT_ALTERNATE_OBJECT_
DIRECTORIES to the empty string.  Every place that var
is used, NULLs are also replaced with empty strings, so
it's ok.
Signed-off-by: NJason Riedy <ejr@cs.berkeley.edu>

Do the default "try xyz.git xyz fails" thing for the directory we get
passed in.

Now that git-clone-pack exists, we actually have somebody requesting
more than just a single head in a pack.  So allow the Jeff's of this
world to clone things with tens of heads.

"git_path()" returns a static pathname pointer into the git directory
using a printf-like format specifier.

"head_ref()" works like "for_each_ref()", except for just the HEAD.

It returns the result SHA1 on stdout, so you can do

	remote=$(git-fetch-pack host:dir branchname)

and it will unpack the objects and "remote" will be the SHA1 name of the
branch on the other side.  You can then save that off, or merge it, or
whatever.

Now the only piece missing is actually generating the pack-file.

It's meant to be used by "git fetch" for the local and ssh case.

It doesn't actually do the fetching now, but it does discover the common
commit point.