hooks/post-receive-email: use plumbing instead of git log/show

This way the hook doesn't have to keep being tweaked as porcelain
learns new features like color and pagination.

While at it, replace the "git rev-list | git shortlog" idiom with
plain "git shortlog" for simplicity.

Except for depending less on the value of settings like '[log]
abbrevCommit', no change in output intended.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
hooks/post-receive-email: force log messages in UTF-8

Git commands write commit messages in UTF-8 by default, but that
default can be overridden by the [i18n] commitEncoding and
logOutputEncoding settings.  With such a setting, the emails written
by the post-receive-email hook use a mixture of encodings:

 1. Log messages use the configured log output encoding, which is
    meant to be whatever encoding works best with local terminals
    (and does not have much to do with what encoding should be used
    for email)

 2. Filenames are left as is: on Linux, usually UTF-8, and in the Mingw
    port (which uses Unicode filesystem APIs), always UTF-8

 3. The "This is an automated email" preface uses a project description
    from .git/description, which is typically in UTF-8 to support
    gitweb.

So (1) is configurable, and (2) and (3) are unconfigurable and
typically UTF-8.  Override the log output encoding to always use UTF-8
when writing the email to get the best chance of a comprehensible
single-encoding email.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
hooks/post-receive-email: set declared encoding to utf-8

Some email clients (e.g., claws-mail) display the message body
incorrectly when the charset is not defined explicitly in a
Content-Type header.  "git log" generates logs in UTF-8 encoding by
default, so add a Content-Type header declaring that encoding to
the emails the post-receive-email example hook sends.

[jn: also setting the Content-Transfer-Encoding so MTAs know what
 kind of mangling might be needed when sending to a non 8-bit clean
 SMTP host]

Requested-by: Alexander Gerasiov <gq@debian.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t5802: add test for connect helper

This is an attempt to reproduce a problem reported for a third-party
custom "connect" remote helper.  The conjecture is that sometimes
"git fetch" wants to make two connections (one for the primary
transfer with 'follow-tags' option set, and then after noticing that
some tags are not packed because the primary transfer did not have
to send any commit that is pointed by them, another to explicitly
ask for the missing tags), and their "connect" helper is not called
in the second request, breaking the "fetch" as a whole.

Unfortunately this test script does not trigger the alleged failure
and happily passes when talking to upload-pack from git-core (see
patch 5/5 for details).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: rename file-scope global "transport" to "gtransport"

Although many functions in this file take a "struct transport" as a
parameter, "fetch_one()" assigns to the global singleton instance
which is a file-scope static, in order to allow a parameterless
signal handler unlock_pack() to access it.

Rename the variable to gtransport to make sure these uses stand out.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: refactor code that prepares a transport

Make a helper function prepare_transport() that returns a transport
to talk to a given remote.

The set_option() helper that used to always affect the file-scope
global "gtransport" now takes a transport as its parameter.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: refactor code that fetches leftover tags

Usually the upload-pack process running on the other side will give
us all the reachable tags we need during the primary object transfer
in do_fetch().  If that does not happen (e.g. the other side may be
running a third-party implementation of upload-pack), we will run
another fetch to pick up leftover tags that we know point at the
commits reachable from our updated tips.

Separate out the code to run this second fetch into a helper
function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: work around "transport-take-over" hack

A Git-aware "connect" transport allows the "transport_take_over" to
redirect generic transport requests like fetch(), push_refs() and
get_refs_list() to the native Git transport handling methods.  The
take-over process replaces transport->data with a fake data that
these method implementations understand.

While this hack works OK for a single request, it breaks when the
transport needs to make more than one requests.  transport->data
that used to hold necessary information for the specific helper to
work correctly is destroyed during the take-over process.

One codepath that this matters is "git fetch" in auto-follow mode;
when it does not get all the tags that ought to point at the history
it got (which can be determined by looking at the peeled tags in the
initial advertisement) from the primary transfer, it internally
makes a second request to complete the fetch.  Because "take-over"
hack has already destroyed the data necessary to talk to the
transport helper by the time this happens, the second request cannot
make a request to the helper to make another connection to fetch
these additional tags.

Mark such a transport as "cannot_reuse", and use a separate
transport to perform the backfill fetch in order to work around
this breakage.

Note that this problem does not manifest itself when running t5802,
because our upload-pack gives you all the necessary auto-followed
tags during the primary transfer.  You would need to step through
"git fetch" in a debugger, stop immediately after the primary
transfer finishes and writes these auto-followed tags, remove the
tag references and repack/prune the repository to convince the
"find-non-local-tags" procedure that the primary transfer failed to
give us all the necessary tags, and then let it continue, in order
to trigger the bug in the secondary transfer this patch fixes.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
gc: reject if another gc is running, unless --force is given

This may happen when `git gc --auto` is run automatically, then the
user, to avoid wait time, switches to a new terminal, keeps working
and `git gc --auto` is started again because the first gc instance has
not clean up the repository.

This patch tries to avoid multiple gc running, especially in --auto
mode. In the worst case, gc may be delayed 12 hours if a daemon reuses
the pid stored in gc.pid.

kill(pid, 0) support is added to MinGW port so it should work on
Windows too.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: remove ternary operator evaluating always to true

The line being changed is deep inside the function builtin_diff.
The variable name_b, which is used to evaluate the ternary expression
must evaluate to true at that position, hence the replacement with
just name_b.

The name_b variable only occurs a few times in that lengthy function:
As a parameter to the function itself:
	static void builtin_diff(const char *name_a,
				 const char *name_b,
				...
The next occurrences are at:
	/* Never use a non-valid filename anywhere if at all possible */
	name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
	name_b = DIFF_FILE_VALID(two) ? name_b : name_a;

	a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
	b_two = quote_two(b_prefix, name_b + (*name_b == '/'));

In the last line of this block 'name_b' is dereferenced and compared
to '/'. This would crash if name_b was NULL. Hence in the following code
we can assume name_b being non-null.

The next occurrence is just as a function argument, which doesn't change
the memory, which name_b points to, so the assumption name_b being not
null still holds:
	emit_rewrite_diff(name_a, name_b, one, two,
				textconv_one, textconv_two, o);

The next occurrence would be the line of this patch. As name_b still must
be not null, we can remove the ternary operator.

Inside the emit_rewrite_diff function there is a also a line
	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
which was also simplified as there is also a dereference before the
ternary operator.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: fix a possible null pointer dereference

The condition in the ternary operator was wrong, hence the wrong char
pointer could be used as the parameter for show_submodule_summary.
one->path may be null, but we definitely need a non null path given
to the function.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Acked-By: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rm: remove unneeded null pointer check

As of 7612a1efdb (2006-06-09 git-rm: honor -n flag.) the variable
'pathspec' seems to be assumed to be never NULL after calling get_pathspec
There was a NULL pointer check after the seen = NULL assignment, which
was removed by that commit. So if pathspec would be NULL now, we'd segfault
in the line accessing the pathspec:
	for (i = 0; pathspec[i] ; i++)

A few lines later, 'pathspec' still cannot be NULL, but that check was
overlooked, hence removing it now.

As the null pointer check was removed, it makes no sense to assign NULL
to seen and 3 lines later another value as there are no conditions in
between.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/git-merge-file: document option "--diff3"

The option "--diff3" was added to "git merge-file" in e0af48e
(xdiff-merge: optionally show conflicts in "diff3 -m" style)
but it was never documented in "Documentation/git-merge-file.txt".
Add documentation for this option.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: fix path when cloning with tilde expansion

The current code fixes the path to make it absolute when cloning, but
doesn't consider tilde expansion, so that scenario fails throwing an
exception because /home/myuser/~/my/repository doesn't exists:

    $ git clone hg::~/my/repository && cd repository && git fetch

Expand the tilde when checking if the path is absolute, so that we don't
fix a path that doesn't need to be.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: ensure shared repo is initialized

6796d49 (remote-hg: use a shared repository store) introduced a bug by
making the shared repository '.git/hg', which is already used before
that patch, so clones that happened before that patch, fail after that
patch, because there's no shared Mercurial repo.

So, instead of simply checking if the directory exists, let's always try
to create an empty shared repository to ensure it's there. This works
because we don't need the initial clone, if the repository is shared,
pulling from the child updates the parent's storage; it's exactly the
same as cloning, so we can simplify the shared repo setup this way while
at the same time fixing the problem.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: add shared repo upgrade

If we have an old organization (v1.8.3), and want to upgrade to a newer
one (v1.8.4), the user would have to fetch the whole repository, instead
we can just move the repository, so the user would not notice any
difference.

Also, remove other clones, so in time they get set up as shared.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t3404: restore specialized rebase-editor following commentchar test

At start of script, t3404 installs a specialized test-editor ($EDITOR)
upon which many of the interactive rebase tests depend.  Late in t3404,
test "rebase -i respects core.commentchar" installs its own custom
editor but neglects to restore the specialized editor when finished.
This oversight will cause later tests, which require the specialized
editor, to fail.  (There are no such tests presently, but a subsequent
patch will introduce one.)  Fix this problem.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t3404: rebase: interactive: demonstrate short SHA-1 collision

The 'todo' sheet for interactive rebase shows abbreviated SHA-1's and
then performs its operations upon those shortened values. This can lead
to an abort if the SHA-1 of a reworded or edited commit is no longer
unique within the abbreviated SHA-1 space and a subsequent SHA-1 in the
todo list has the same abbreviated value.

For example:

  edit f00dfad first
  pick badbeef second

If, after editing, the new SHA-1 of "first" is now
badbeef5ba78983324dff5265c80c4490d5a809a, then the subsequent 'pick
badbeef second' will fail since badbeef is no longer a unique SHA-1
abbreviation:

  error: short SHA1 badbeef is ambiguous.
  fatal: Needed a single revision
  Invalid commit name: badbeef

Demonstrate this problem with a couple of specially crafted commits
which initially have distinct abbreviated SHA-1's, but for which the
abbreviated SHA-1's collide after a simple rewording of the first
commit's message.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase: interactive: fix short SHA-1 collision

The 'todo' sheet for interactive rebase shows abbreviated SHA-1's and
then performs its operations upon those shortened values. This can lead
to an abort if the SHA-1 of a reworded or edited commit is no longer
unique within the abbreviated SHA-1 space and a subsequent SHA-1 in the
todo list has the same abbreviated value.

For example:

  edit f00dfad first
  pick badbeef second

If, after editing, the new SHA-1 of "first" is now
badbeef5ba78983324dff5265c80c4490d5a809a, then the subsequent 'pick
badbeef second' will fail since badbeef is no longer a unique SHA-1
abbreviation:

  error: short SHA1 badbeef is ambiguous.
  fatal: Needed a single revision
  Invalid commit name: badbeef

Fix this problem by expanding the SHA-1's in the todo list before
performing the operations.

[es: also collapse & expand SHA-1's for --edit-todo]

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-p4: Fix occasional truncation of symlink contents.

Symlink contents in p4 print sometimes have a trailing
new line character, but sometimes it doesn't. git-p4
should only remove the last character if that character
is '\n'.

Signed-off-by: Alex Juncu <ajuncu@ixiacom.com>
Signed-off-by: Alex Badea <abadea@ixiacom.com>
Acked-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>