t/README: tests can use perl even with NO_PERL

The git build system supports a NO_PERL switch to avoid installing
perl bindings or other features (like "git add --patch") that rely on
perl on runtime, but even with NO_PERL it has not been possible for a
long time to run tests without perl.  Helpers such as

	nul_to_q () {
		"$PERL_PATH" -pe 'y/\000/Q/'
	}

use perl as a better tr or sed and are regularly used in tests without
worrying to add a PERL prerequisite.

Perl is portable enough that it seems fine to keep relying on it for
this kind of thing in tests (and more readable than the alternative of
trying to find POSIXy equivalents).  Update the test documentation to
clarify this.

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc/howto: warn about (dumb)http server document being too old

Describe when it is still applicable, and tell people where to go
for most normal cases.

Signed-off-by: Sitaram Chamarty <sitaram@atc.tcs.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
use @@PERL@@ in built scripts

Several of the built shell commands invoke a bare "perl" to
perform some one-liners. This will use the first perl in the
PATH rather than the one specified by the user's SHELL_PATH.
We are not asking these perl invocations to do anything
exotic, so typically any old system perl will do; however,
in some cases the system perl may have unexpected behavior
(e.g., by handling line endings differently). We should err
on the side of using the perl the user pointed us to.

The downside of this is that on systems with a sane perl
setup, we no longer find the perl at runtime, but instead
point to a static perl (like /usr/bin/perl). That means we
will not handle somebody moving perl without rebuilding git,
whereas before we tracked it just fine. This is probably not
a big deal, though, as the built perl scripts already
suffered from this.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t: provide a perl() function which uses $PERL_PATH

Once upon a time, we assumed that calling a bare "perl" in
the test scripts was OK, because we would find the perl from
the user's PATH, and we were only asking that perl to do
basic operations that work even on old versions of perl.

Later, we found that some systems really prefer to use
$PERL_PATH even for these basic cases, because the system
perl misbehaves in some way (e.g., by handling line endings
differently). We then switched "perl" invocations to
"$PERL_PATH" to respect the user's choice.

Having to use "$PERL_PATH" is ugly and cumbersome, though.
Instead, let's provide a perl() shell function that tests
can use, which will transparently do the right thing.

Unfortunately, test writers still have to use $PERL_PATH in
certain situations, so we still need to keep the advice in
the README.

Note that this may fix test failures in t5004, t5503, t6002,
t6003, t6300, t8001, and t8002, depending on your system's
perl setup. All of these can be detected by running:

  ln -s /bin/false bin-wrappers/perl
  make test

which fails before this patch, and passes after.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t: use perl instead of "$PERL_PATH" where applicable

As of the last commit, we can use "perl" instead of
"$PERL_PATH" when running tests, as the former is now a
function which uses the latter. As the shorter "perl" is
easier on the eyes, let's switch to using it everywhere.

This is not quite a mechanical s/$PERL_PATH/perl/
replacement, though. There are some places where we invoke
perl from a script we generate on the fly, and those scripts
do not have access to our internal shell functions. The
result can be double-checked by running:

  ln -s /bin/false bin-wrappers/perl
  make test

which continues to pass even after this patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: fix large pushes with GSSAPI

Due to an interaction between the way libcurl handles GSSAPI authentication over
HTTP and the way git uses libcurl, large pushes (those over http.postBuffer
bytes) would fail due to an authentication failure requiring a rewind of the
curl buffer.  Such a rewind was not possible because the data did not fit into
the entire buffer.

Enable the use of the Expect: 100-continue header for large requests where the
server offers GSSAPI authentication to avoid this issue, since the request would
otherwise fail.  This allows git to get the authentication data right before
sending the pack contents.  Existing cases where pushes would succeed, including
small requests using GSSAPI, still disable the use of 100 Continue, as it causes
problems for some remote HTTP implementations (servers and proxies).

Signed-off-by: Brian M. Carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-base: teach "--fork-point" mode

The "git pull --rebase" command computes the fork point of the
branch being rebased using the reflog entries of the "base" branch
(typically a remote-tracking branch) the branch's work was based on,
in order to cope with the case in which the "base" branch has been
rewound and rebuilt.  For example, if the history looked like this:

                     o---B1
                    /
    ---o---o---B2--o---o---o---Base
            \
             B3
              \
               Derived

where the current tip of the "base" branch is at Base, but earlier
fetch observed that its tip used to be B3 and then B2 and then B1
before getting to the current commit, and the branch being rebased
on top of the latest "base" is based on commit B3, it tries to find
B3 by going through the output of "git rev-list --reflog base" (i.e.
Base, B1, B2, B3) until it finds a commit that is an ancestor of the
current tip "Derived".

Internally, we have get_merge_bases_many() that can compute this
with one-go.  We would want a merge-base between Derived and a
fictitious merge commit that would result by merging all the
historical tips of "base".  When such a commit exist, we should get
a single result, which exactly match one of the reflog entries of
"base".

Teach "git merge-base" a new mode, "--fork-point", to compute
exactly that.

Helped-by: Martin von Zweigbergk <martinvonz@gmail.com>
Helped-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cvsserver: Determinize output to combat Perl 5.18 hash randomization

Perl 5.18 randomizes the seed used by its hash function, so iterating
through hashes results in different orders from run to run:
  http://perldoc.perl.org/perl5180delta.html#Hash-overhaul

This usually broke t9400 (gitcvs.dbname, gitcvs.ext.dbname, when
running cmp on two .sqlite files) and t9402 (check [cvswork3] diff,
when running test_cmp on two diffs).

To fix this, hide the internal order of hashes with sort when sending
output or running database queries.

(An alternative workaround is PERL_HASH_SEED=0, but this seems nicer.)

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
count-objects: recognize .bitmap in garbage-checking

Count-objects will report any "garbage" files in the packs
directory, including

 - files whose extensions it does not know (case 1), and

 - files whose matching ".pack" file is missing (case 2).

Without having learned about ".bitmap" files, the current code
reports all such files as garbage (case 1), even if their pack
exists.  Instead, they should be treated as case 2.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Avoid difference in tr semantics between System V and BSD

Solaris' tr (both /usr/bin/ and /usr/xpg4/bin) uses the System V
semantics for tr whereby string1's length is truncated to the length
of string2 if string2 is shorter. The BSD semantics, as used by GNU tr
see string2 padded to the length of string1 using the final character
in string2. POSIX explicitly doesn't specify the correct behavior
here, making both equally valid.

This difference means that Solaris' native tr implementations produce
different results for tr ":\t\n" "\0" than GNU tr. This breaks a few
tests in t0008-ignores.sh.

Possible fixes for this are to make string2 be "\0\0\0" or "[\0*]".

Instead, use perl to perform these transliterations which means we
don't need to worry about the difference at all. Since we're replacing
tr with perl, we also use perl to replace the sed invocations used to
transform the files.

Replace four identical transforms with a function named
broken_c_unquote. Replace the other two identical transforms with a
fuction named broken_c_unquote_verbose.

Signed-off-by: Ben Walton <bdwalton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
subtree: add makefile target for html docs

The Makefile currently builds the roff manpage, but not the
html form. As some people may prefer the latter, let's make
it an option to build that, too. We also wire it into "make
doc" so that it is built by default.

This patch does not build or install it as part of
"install-doc"; that would require extra infrastructure to
handle installing the html as we do in git's regular
Documentation/ tree. That can come later if somebody is
interested.

Tested-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit: Add -f, --fixes <commit> option to add Fixes: line

Linux Kernel Summit 2013 decided on a commit message convention to
identify commits containing bugs fixed by a commit: a "Fixes:" line,
included in the standard commit footer (along with "Signed-off-by:" if
present), containing an abbreviated commit hash (at least 12 characters
to keep it valid for a long time) and the subject of the commit (for
human readers).  This helps people (or automated tools) determine how
far to backport a commit.

Add a command line option for git commit to automatically construct the
"Fixes:" line for a commit.  This avoids the need to manually construct
that line by copy-pasting the commit hash and subject.

Also works with --amend to modify an existing commit's message.  To add
a Fixes line to an earlier commit in a series, use rebase -i and add the
following line after the existing commit:
x git commit --amend --no-edit --fixes $commit_containing_bug

Generalize append_signoff to support appending arbitrary extra lines to
a commit in the signoff block; this avoids duplicating the logic to find
or construct that block.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jl/submodule-mv' into jch

Moving a regular file in a repository with a .gitmodules file was
producing a warning 'Could not find section in .gitmodules where
path=<filename>'.

* jl/submodule-mv:
  mv: Fix spurious warning when moving a file in presence of submodules
Merge branch 'ap/remote-hg-unquote-cquote' into jch

A fast-import stream expresses a pathname with funny characters by
quoting them in C style; remote-hg remote helper forgot to unquote
such a path.

* ap/remote-hg-unquote-cquote:
  remote-hg: unquote C-style paths when exporting
Merge branch 'jk/for-each-ref-skip-parsing' into jch

* jk/for-each-ref-skip-parsing:
  for-each-ref: avoid loading objects to print %(objectname)
Merge branch 'jk/pack-corruption-post-mortem' into jch

* jk/pack-corruption-post-mortem:
  howto: add article on recovering a corrupted object
Merge branch 'jk/reset-p-current-head-fix' into jch

"git reset -p HEAD" has codepath to special case it from resetting
to contents of other commits, but recent change broke it.

* jk/reset-p-current-head-fix:
  reset: pass real rev name to add--interactive
  add-interactive: handle unborn branch in patch mode
Merge branch 'js/test-help-format-windows-port-fix' into jch

* js/test-help-format-windows-port-fix:
  t3200: do not open a HTML manual page when DEFAULT_MAN_FORMAT is html
Merge branch 'js/tests-windows-port-fix' into jch

* js/tests-windows-port-fix:
  tests: undo special treatment of CRLF for Windows
  Windows: a test_cmp that is agnostic to random LF <> CRLF conversions
  t5300-pack-object: do not compare binary data using test_cmp
Merge branch 'rs/web-browse-xdg-open' into jch

* rs/web-browse-xdg-open:
  web--browse: Add support for xdg-open