make config --add behave correctly for empty and NULL values

Currently if we have a config file like,
[foo]
        baz
        bar =

and we try something like, "git config --add foo.baz roll", Git will
segfault. Moreover, for "git config --add foo.bar roll", it will
overwrite the original value instead of appending after the existing
empty value.

The problem lies with the regexp used for simulating --add in
`git_config_set_multivar_in_file()`, "^$", which in ideal case should
not match with any string but is true for empty strings. Instead use a
regexp like "a^" which can not be true for any string, empty or not.

For removing the segfault add a check for NULL values in `matches()` in
config.c.

Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
send-pack: take refspecs over stdin

Pushing a large number of refs works over most transports,
because we implement send-pack as an internal function.
However, it can sometimes fail when pushing over http,
because we have to spawn "git send-pack --stateless-rpc" to
do the heavy lifting, and we pass each refspec on the
command line. This can cause us to overflow the OS limits on
the size of the command line for a large push.

We can solve this by giving send-pack a --stdin option and
using it from remote-curl.  We already dealt with this on
the fetch-pack side in 078b895 (fetch-pack: new --stdin
option to read refs from stdin, 2012-04-02). The stdin
option (and in particular, its use of packet-lines for
stateless-rpc input) is modeled after that solution.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit: provide a function to find a header in a buffer

Usually when we parse a commit, we read it line by line and
handle each individual line (e.g., parse_commit and
parse_commit_header).  Sometimes, however, we only care
about extracting a single header. Code in this situation is
stuck doing an ad-hoc parse of the commit buffer.

Let's provide a reusable function to locate a header within
the commit.  The code is modeled after pretty.c's
get_header, which is used to extract the encoding.

Since some callers may not have the "struct commit" to go
along with the buffer, we drop that parameter.  The only
thing lost is a warning for truncated commits, but that's
OK.  This shouldn't happen in practice, and even if it does,
there's no particular reason that this function needs to
complain about it. It either finds the header it was asked
for, or it doesn't (and in the latter case, the caller will
typically complain).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
record_author_date(): fix memory leak on malformed commit

If we hit the end-of-header without finding an "author"
line, we just return from the function. We should jump to
the fail_exit path to clean up the buffer that we may have
allocated.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
record_author_date(): use find_commit_header()

This saves us some manual parsing and makes the code more
readable.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
date: use strbufs in date-formatting functions

Many of the date functions write into fixed-size buffers.
This is a minor pain, as we have to take special
precautions, and frequently end up copying the result into a
strbuf or heap-allocated buffer anyway (for which we
sometimes use strcpy!).

Let's instead teach parse_date, datestamp, etc to write to a
strbuf. The obvious downside is that we might need to
perform a heap allocation where we otherwise would not need
to. However, it turns out that the only two new allocations
required are:

  1. In test-date.c, where we don't care about efficiency.

  2. In determine_author_info, which is not performance
     critical (and where the use of a strbuf will help later
     refactoring).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
teach fast-export an --anonymize option

Sometimes users want to report a bug they experience on
their repository, but they are not at liberty to share the
contents of the repository. It would be useful if they could
produce a repository that has a similar shape to its history
and tree, but without leaking any information. This
"anonymized" repository could then be shared with developers
(assuming it still replicates the original problem).

This patch implements an "--anonymize" option to
fast-export, which generates a stream that can recreate such
a repository. Producing a single stream makes it easy for
the caller to verify that they are not leaking any useful
information. You can get an overview of what will be shared
by running a command like:

  git fast-export --anonymize --all |
  perl -pe 's/\d+/X/g' |
  sort -u |
  less

which will show every unique line we generate, modulo any
numbers (each anonymized token is assigned a number, like
"User 0", and we replace it consistently in the output).

In addition to anonymizing, this produces test cases that
are relatively small (compared to the original repository)
and fast to generate (compared to using filter-branch, or
modifying the output of fast-export yourself). Here are
numbers for git.git:

  $ time git fast-export --anonymize --all \
         --tag-of-filtered-object=drop >output
  real    0m2.883s
  user    0m2.828s
  sys     0m0.052s

  $ gzip output
  $ ls -lh output.gz | awk '{print $5}'
  2.9M

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
docs/fast-export: explain --anonymize more completely

The original commit made mention of this option, but not why
one might want it or how they might use it. Let's try to be
a little more thorough, and also explain how to confirm that
the output really is anonymous.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t0027: Tests for core.eol=native, eol=lf, eol=crlf

Add test cases for core.eol "native" and "" (unset).
(MINGW uses CRLF, all other systems LF as native line endings)

Add test cases for the attributes "eol=lf" and "eol=crlf"

Other minor changes:
- Use the more portable 'tr' instead of 'od -c' to convert '\n' into 'Q'
  and '\0' into 'N'
- Style fixes for shell functions according to the coding guide lines
- Replace "txtbin" with "attr"

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
contrib/svn-fe: fix Makefile

Fixes several problems:
  * include config.mak.uname, config.mak.autogen and config.mak
    in order to use settings for prefix and other such things;
  * link xdiff/lib.a as it is a requirement for libgit.a;
  * fix CFLAGS, LDFLAGS and EXTLIBS for Linux and Mac OS X.

Signed-off-by: Maxim Bublis <satori@yandex-team.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_index_from(): catch out of order entries when reading an index file

Signed-off-by: Jaime Soriano Pastor <jsorianopastor@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_index_unmerged(): remove unnecessary loop index adjustment

Signed-off-by: Jaime Soriano Pastor <jsorianopastor@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t9300: test filedelete command

Add new fast-import test series for filedelete command.

Signed-off-by: Maxim Bublis <satori@yandex-team.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fast-import: fix segfault in store_tree()

Branch tree is NULLified by filedelete command if we are trying
to delete root tree. Add sanity check and use load_tree() in that case.

Signed-off-by: Maxim Bublis <satori@yandex-team.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
determine_author_info(): reuse parsing functions

Rather than parsing the header manually to find the "author"
field, and then parsing its sub-parts, let's use
find_commit_header and split_ident_line. This is shorter and
easier to read, and should do a more careful parsing job.

For example, the current parser could find the end-of-email
right-bracket across a newline (for a malformed commit), and
calculate a bogus gigantic length for the date (by using
"eol - rb").

As a bonus, this also plugs a memory leak when we pull the
date field from an existing commit (we still leak the name
and email buffers, which will be fixed in a later commit).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
determine_author_info(): copy getenv output

When figuring out the author name for a commit, we may end
up either pointing to const storage from getenv("GIT_AUTHOR_*"),
or to newly allocated storage based on an existing commit or
the --author option.

Using const pointers to getenv's return has two problems:

  1. It is not guaranteed that the return value from getenv
     remains valid across multiple calls.

  2. We do not know whether to free the values at the end,
     so we just leak them.

We can solve both by duplicating the string returned by
getenv().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pretty: provide a strict ISO 8601 date format

Git's "ISO" date format does not really conform to the ISO 8601
standard due to small differences, and it cannot be parsed by ISO
8601-only parsers, e.g. those of XML toolchains.

The output from "--date=iso" deviates from ISO 8601 in these ways:

  - a space instead of the `T` date/time delimiter
  - a space between time and time zone
  - no colon between hours and minutes of the time zone

Add a strict ISO 8601 date format for displaying committer and
author dates.  Use the '%aI' and '%cI' format specifiers and add
'--date=iso-strict' or '--date=iso8601-strict' date format names.

See http://thread.gmane.org/gmane.comp.version-control.git/255879 and
http://thread.gmane.org/gmane.comp.version-control.git/52414/focus=52585
for discussion.

Signed-off-by: Beat Bolli <bbolli@ewanet.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
index-pack: fix race condition with duplicate bases

When we are resolving deltas in an indexed pack, we do it by
first selecting a potential base (either one stored in full
in the pack, or one created by resolving another delta), and
then resolving any deltas that use that base.  When we
resolve a particular delta, we flip its "real_type" field
from OBJ_{REF,OFS}_DELTA to whatever the real type is.

We assume that traversing the objects this way will visit
each delta only once. This is correct for most packs; we
visit the delta only when we process its base, and each
object (and thus each base) appears only once. However, if a
base object appears multiple times in the pack, we will try
to resolve any deltas based on it once for each instance.

We can detect this case by noting that a delta we are about
to resolve has already had its real_type field flipped, and
we already do so with an assert().  However, if multiple
threads are in use, we may race with another thread on
comparing and flipping the field. We need to synchronize the
access.

The right mechanism for doing this is a compare-and-swap (we
atomically "claim" the delta for our own and find out
whether our claim was successful). We can implement this
in C by using a pthread mutex to protect the operation. This
is not the fastest way of doing a compare-and-swap; many
processors provide instructions for this, and gcc and other
compilers provide builtins to access them. However, some
experiments showed that lock contention does not cause a
significant slowdown here. Adding c-a-s support for many
compilers would increase the maintenance burden (and we
would still end up including the pthread version as a
fallback).

Note that we only need to touch the OBJ_REF_DELTA codepath
here. An OBJ_OFS_DELTA object points to its base using an
offset, and therefore has only one base, even if another
copy of that base object appears in the pack (we do still
touch it briefly because the setting of real_type is
factored out of resolve_data).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
connect: simplify check_ref() using skip_prefix() and starts_with()

Both callers of check_ref() pass in NUL-terminated strings for name.
Remove the len parameter and then use skip_prefix() and starts_with()
instead of memcmp() to check if it starts with certain strings.  This
gets rid of several magic string length constants and a strlen() call.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-write: simplify index_pack_lockfile using skip_prefix() and xstrfmt()

Get rid of magic string length constants by using skip_prefix() instead
of memcmp() and use xstrfmt() for building a string instead of a
PATH_MAX-sized buffer, snprintf() and xstrdup().

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>