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Author SHA1 Message Date
Junio C Hamano
11667316d0 topology tests: teach a helper to set author dates as well
Introduce on_dates helper that is similar to on_committer_date but
also sets the author date, not just the committer date.

At this step, just set the same timestamp to the author date as the
committer date, as no test looks at author date yet.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 11:16:31 -07:00
Junio C Hamano
b9f80fdaea t6003: add --date-order test
The "--date-order" output is a slight twist of "--topo-order" in
that commits from parallel histories are shown in their committer
date order without an attempt to clump commits from a single line
of history together like --topo-order does.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 11:16:31 -07:00
Junio C Hamano
841dc6935e topology tests: teach a helper to take abbreviated timestamps
The on_committer_date helper in t/lib-t6000 is used in t6002 and
t6003 with timestamps on a single day within a single minute
(i.e. 1971-08-16 00:00) and the tests repeat this over and over.

The actual value of the timestamp, however, does not matter very
much; only their relative ordering does.

Introduce another helper to expand only the suffix of the timestamp
to a full timestamp to make the lines shorter, and use it in this
helper.  Also, because all the commits in the test are made with
specific GIT_COMMITTER_DATE, stop unsetting it at the end of the
helper.

We'll be specifying the author timestamp to these test commits in a
later patch, which will be helped with this change.

Also remove a test that was commented-out from t6003; it used to
test a commit with the same parent listed twice, which was allowed
by mistake but was fixed long time ago.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 11:15:32 -07:00
Junio C Hamano
50e5a25222 t/lib-t6000: style fixes
Mostly fixes to initial indentation with 8-SP (they should be HT)
and wrapping long lines.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 10:16:01 -07:00
Yaakov Selkowitz
cc2f6b6865 web--browse: support /usr/bin/cygstart on Cygwin
While both GUI and console Cygwin browsers do exist, anecdotal evidence
suggests most users rely on their native Windows browser.  cygstart,
which is a long-standing part of the base Cygwin installation, will
cause the page to be opened in the default Windows browser (the one
registered to open .html files).

Signed-off-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 09:05:15 -07:00
Jeff King
266f1fdfa9 transport-helper: be quiet on read errors from helpers
Prior to commit 81d340d4, we did not print any error message
if a remote transport helper died unexpectedly. If a helper
did not print any error message (e.g., because it crashed),
the user could be left confused. That commit tried to
rectify the situation by printing a note that the helper
exited unexpectedly.

However, this makes a much more common case worse: when a
helper does die with a useful message, we print the extra
"Reading from 'git-remote-foo failed" message. This can also
end up confusing users, as they may not even know what
remote helpers are (e.g., the fact that http support comes
through git-remote-https is purely an implementation detail
that most users do not know or care about).

Since we do not have a good way of knowing whether the
helper printed a useful error, and since the common failure
mode is for it to do so, let's default to remaining quiet.
Debuggers can dig further by setting GIT_TRANSPORT_HELPER_DEBUG.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 09:03:53 -07:00
Ramkumar Ramachandra
c0add3073a completion: complete diff --word-diff
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 08:52:16 -07:00
Thomas Rast
212eb96a96 apply: carefully strdup a possibly-NULL name
2901bbe (apply: free patch->{def,old,new}_name fields, 2012-03-21)
cleaned up the memory management of filenames in the patches, but
forgot that find_name_traditional() can return NULL as a way of saying
"I couldn't find a name".

That NULL unfortunately gets passed into xstrdup() next, resulting in
a segfault.  Use null_strdup() so as to safely propagate the null,
which will let us emit the correct error message.

Reported-by: DevHC on #git
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-21 08:36:07 -07:00
Junio C Hamano
21ff9151e8 Update draft release notes to 1.8.4 2013-06-20 16:13:41 -07:00
Junio C Hamano
0c36f3a198 Merge branch 'cm/remote-mediawiki'
* cm/remote-mediawiki:
  git-remote-mediawiki: display message when launched directly
2013-06-20 16:02:42 -07:00
Junio C Hamano
50f6909929 Merge branch 'rs/match-trees-refactor'
Code cleanup.

* rs/match-trees-refactor:
  match-trees: factor out fill_tree_desc_strict
2013-06-20 16:02:40 -07:00
Junio C Hamano
02dfccfa40 Merge branch 'rs/logical-vs-binary-or'
Code cleanup.

* rs/logical-vs-binary-or:
  use logical OR (||) instead of binary OR (|) in logical context
2013-06-20 16:02:39 -07:00
Junio C Hamano
73018c0f0b Merge branch 'mm/color-auto-default'
Flip the default for color.ui to 'auto', which is what many
tutorials recommend new users to do.

* mm/color-auto-default:
  make color.ui default to 'auto'
  config: refactor management of color.ui's default value
2013-06-20 16:02:33 -07:00
Junio C Hamano
08bcd774f4 Merge branch 'rs/discard-index-discard-array'
* rs/discard-index-discard-array:
  read-cache: free cache in discard_index
  read-cache: add simple performance test
2013-06-20 16:02:30 -07:00
Junio C Hamano
8f0c843aab Merge branch 'nd/traces'
* nd/traces:
  git.txt: document GIT_TRACE_PACKET
  core: use env variable instead of config var to turn on logging pack access
2013-06-20 16:02:28 -07:00
Junio C Hamano
01c0615dce Merge branch 'fc/show-non-empty-errors-in-test'
* fc/show-non-empty-errors-in-test:
  test: test_must_be_empty helper
2013-06-20 16:02:24 -07:00
Junio C Hamano
0846fe1a83 Merge branch 'fc/makefile'
Makefile simplification.

* fc/makefile:
  Makefile: use $^ to avoid listing prerequisites on the command line
  build: do not install git-remote-testgit
  build: generate and clean test scripts
2013-06-20 16:02:21 -07:00
Junio C Hamano
c0266ed275 Merge branch 'js/test-ln-s-add'
Many tests that check the behaviour of symbolic links stored in the
index or the tree objects do not have to be skipped on a filesystem
that lack symbolic link support.

* js/test-ln-s-add:
  t4011: remove SYMLINKS prerequisite
  t6035: use test_ln_s_add to remove SYMLINKS prerequisite
  t3509, t4023, t4114: use test_ln_s_add to remove SYMLINKS prerequisite
  t3100: use test_ln_s_add to remove SYMLINKS prerequisite
  t3030: use test_ln_s_add to remove SYMLINKS prerequisite
  t0000: use test_ln_s_add to remove SYMLINKS prerequisite
  tests: use test_ln_s_add to remove SYMLINKS prerequisite (trivial cases)
  tests: introduce test_ln_s_add
  t3010: modernize style
  test-chmtime: Fix exit code on Windows
2013-06-20 16:02:18 -07:00
Junio C Hamano
6aeb74ec89 Merge branch 'nd/make-wildmatch-default'
* nd/make-wildmatch-default:
  Makefile: promote wildmatch to be the default fnmatch implementation
2013-06-20 16:02:14 -07:00
Thomas Rast
b4dc085a8d pull: merge into unborn by fast-forwarding from empty tree
The logic for pulling into an unborn branch was originally
designed to be used on a newly-initialized repository
(d09e79c, git-pull: allow pulling into an empty repository,
2006-11-16).  It thus did not initially deal with
uncommitted changes in the unborn branch.  The case of an
_unstaged_ untracked file was fixed by 4b3ffe5 (pull: do not
clobber untracked files on initial pull, 2011-03-25).
However, it still clobbered existing staged files, both when
the file exists in the merged commit (it will be
overwritten), and when it does not (it will be deleted).

We fix this by doing a two-way merge, where the "current"
side of the merge is an empty tree, and the "target" side is
HEAD (already updated to FETCH_HEAD at this point).  This
amounts to claiming that all work in the index was done vs.
an empty tree, and thus all content of the index is
precious.

Note that this use of read-tree just gives us protection
against overwriting index and working tree changes. It will
not actually result in a 3-way merge conflict in the index.
This is fine, as this is a rare situation, and the conflict
would not be interesting anyway (it must, by definition, be
an add/add conflict with the whole content conflicting). And
it makes it simpler for the user to recover, as they have no
HEAD to "git reset" back to.

Reported-by: Stefan Schüßler <mail@stefanschuessler.de>
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:51:35 -07:00
Jeff King
9f48f2bd9a pull: update unborn branch tip after index
When commit d09e79c taught git to pull into an unborn
branch, it first updated the unborn branch to point at the
pulled commit, and then used read-tree to update the index
and working tree. That ordering made sense, since any
failure of the latter step would be due to filesystem
errors, and one could then recover with "git reset --hard".

Later, commit 4b3ffe5 added extra safety for existing files
in the working tree by asking read-tree to bail out when it
would overwrite such a file. This error mode is much less
"your pull failed due to random errors" and more like "we
reject this pull because it would lose data". In that case,
it makes sense not to update the HEAD ref, just as a regular
rejected merge would do.

This patch reverses the order of the update-ref and
read-tree calls, so that we do not touch the HEAD ref at all if a
merge is rejected. This also means that we would not update
HEAD in case of a transient filesystem error, but those are
presumably less rare (and one can still recover by repeating
the pull, or by accessing FETCH_HEAD directly).

While we're reorganizing the code, we can drop the "exit 1"
from the end of our command chain. We exit immediately
either way, and just calling exit without an argument will
use the exit code from the last command.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:51:25 -07:00
Michael Haggerty
5d478f5ca1 refs: do not invalidate the packed-refs cache unnecessarily
Now that we keep track of the packed-refs file metadata, we can detect
when the packed-refs file has been modified since we last read it, and
we do so automatically every time that get_packed_ref_cache() is
called.  So there is no need to invalidate the cache automatically
when lock_packed_refs() is called; usually the old copy will still be
valid.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Jeff King
98eeb09e8a for_each_ref: load all loose refs before packed refs
If we are iterating through the refs using for_each_ref (or
any of its sister functions), we can get into a race
condition with a simultaneous "pack-refs --prune" that looks
like this:

  0. We have a large number of loose refs, and a few packed
     refs. refs/heads/z/foo is loose, with no matching entry
     in the packed-refs file.

  1. Process A starts iterating through the refs. It loads
     the packed-refs file from disk, then starts lazily
     traversing through the loose ref directories.

  2. Process B, running "pack-refs --prune", writes out the
     new packed-refs file. It then deletes the newly packed
     refs, including refs/heads/z/foo.

  3. Meanwhile, process A has finally gotten to
     refs/heads/z (it traverses alphabetically). It
     descends, but finds nothing there.  It checks its
     cached view of the packed-refs file, but it does not
     mention anything in "refs/heads/z/" at all (it predates
     the new file written by B in step 2).

The traversal completes successfully without mentioning
refs/heads/z/foo at all (the name, of course, isn't
important; but the more refs you have and the farther down
the alphabetical list a ref is, the more likely it is to hit
the race). If refs/heads/z/foo did exist in the packed refs
file at state 0, we would see an entry for it, but it would
show whatever sha1 the ref had the last time it was packed
(which could be an arbitrarily long time ago).

This can be especially dangerous when process A is "git
prune", as it means our set of reachable tips will be
incomplete, and we may erroneously prune objects reachable
from that tip (the same thing can happen if "repack -ad" is
used, as it simply drops unreachable objects that are
packed).

This patch solves it by loading all of the loose refs for
our traversal into our in-memory cache, and then refreshing
the packed-refs cache. Because a pack-refs writer will
always put the new packed-refs file into place before
starting the prune, we know that any loose refs we fail to
see will either truly be missing, or will have already been
put in the packed-refs file by the time we refresh.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Jeff King
ca9199300e get_packed_ref_cache: reload packed-refs file when it changes
Once we read the packed-refs file into memory, we cache it
to save work on future ref lookups. However, our cache may
be out of date with respect to what is on disk if another
process is simultaneously packing the refs. Normally it
is acceptable for us to be a little out of date, since there
is no guarantee whether we read the file before or after the
simultaneous update. However, there is an important special
case: our packed-refs file must be up to date with respect
to any loose refs we read. Otherwise, we risk the following
race condition:

  0. There exists a loose ref refs/heads/master.

  1. Process A starts and looks up the ref "master". It
     first checks $GIT_DIR/master, which does not exist. It
     then loads (and caches) the packed-refs file to see if
     "master" exists in it, which it does not.

  2. Meanwhile, process B runs "pack-refs --all --prune". It
     creates a new packed-refs file which contains
     refs/heads/master, and removes the loose copy at
     $GIT_DIR/refs/heads/master.

  3. Process A continues its lookup, and eventually tries
     $GIT_DIR/refs/heads/master.  It sees that the loose ref
     is missing, and falls back to the packed-refs file. But
     it examines its cached version, which does not have
     refs/heads/master. After trying a few other prefixes,
     it reports master as a non-existent ref.

There are many variants (e.g., step 1 may involve process A
looking up another ref entirely, so even a fully qualified
refname can fail). One of the most interesting ones is if
"refs/heads/master" is already packed. In that case process
A will not see it as missing, but rather will report
whatever value happened to be in the packed-refs file before
process B repacked (which might be an arbitrarily old
value).

We can fix this by making sure we reload the packed-refs
file from disk after looking at any loose refs. That's
unacceptably slow, so we can check its stat()-validity as a
proxy, and read it only when it appears to have changed.

Reading the packed-refs file after performing any loose-ref
system calls is sufficient because we know the ordering of
the pack-refs process: it always makes sure the newly
written packed-refs file is installed into place before
pruning any loose refs. As long as those operations by B
appear in their executed order to process A, by the time A
sees the missing loose ref, the new packed-refs file must be
in place.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
3861253224 add a stat_validity struct
It can sometimes be useful to know whether a path in the
filesystem has been updated without going to the work of
opening and re-reading its content. We trust the stat()
information on disk already to handle index updates, and we
can use the same trick here.

This patch introduces a "stat_validity" struct which
encapsulates the concept of checking the stat-freshness of a
file. It is implemented on top of "struct stat_data" to
reuse the logic about which stat entries to trust for a
particular platform, but hides the complexity behind two
simple functions: check and update.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
c21d39d7c7 Extract a struct stat_data from cache_entry
Add public functions fill_stat_data() and match_stat_data() to work
with it.  This infrastructure will later be used to check the validity
of other types of file.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
4f6b83e370 packed_ref_cache: increment refcount when locked
Increment the packed_ref_cache reference count while it is locked to
prevent its being freed.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
8baf2bb99a do_for_each_entry(): increment the packed refs cache refcount
This function calls a user-supplied callback function which could do
something that causes the packed refs cache to be invalidated.  So
acquire a reference count on the data structure to prevent our copy
from being freed while we are iterating over it.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
5f5e2a8868 refs: manage lifetime of packed refs cache via reference counting
In struct packed_ref_cache, keep a count of the number of users of the
data structure.  Only free the packed ref cache when the reference
count goes to zero rather than when the packed ref cache is cleared.
This mechanism will be used to prevent the cache data structure from
being freed while it is being iterated over.

So far, only the reference in struct ref_cache::packed is counted;
other users will be adjusted in separate commits.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
9f69d29770 refs: implement simple transactions for the packed-refs file
Handle simple transactions for the packed-refs file at the
packed_ref_cache level via new functions lock_packed_refs(),
commit_packed_refs(), and rollback_packed_refs().

Only allow the packed ref cache to be modified (via add_packed_ref())
while the packed refs file is locked.

Change clone to add the new references within a transaction.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
2fff781290 refs: wrap the packed refs cache in a level of indirection
As we know, we can solve any problem in this manner.  In this case,
the problem is to avoid freeing a packed refs cache while somebody is
using it.  So add a level of indirection as a prelude to
reference-counting the packed refs cache.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
267f9a8cc8 pack_refs(): split creation of packed refs and entry writing
Split pack_refs() into multiple passes:

* Iterate over loose refs.  For each one that can be turned into a
  packed ref, create a corresponding entry in the packed refs cache.

* Write the packed refs to the packed-refs file.

This change isolates the mutation of the packed-refs file to a single
place.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:17 -07:00
Michael Haggerty
7b40d39638 repack_without_ref(): split list curation and entry writing
The repack_without_ref() function first removes the deleted ref from
the internal packed-refs list, then writes the packed-refs list to
disk, omitting any broken or stale entries.  This patch splits that
second step into multiple passes:

* collect the list of refnames that should be deleted from packed_refs

* delete those refnames from the cache

* write the remainder to the packed-refs file

The purpose of this change is to make the "write the remainder" part
reusable.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 15:50:16 -07:00
Torsten Bögershausen
bed9470489 t7400: test of UTF-8 submodule names pass under Mac OS
submodules with names using UTF-8 need core.precomposeunicode true
under Mac OS X, set it in the test case.

Improve the portability:

  - Not all shells on all OS may understand literal UTF-8 strings.
  - Use a help variable filled by printf, as we do it in e.g. t0050.

"strange names" can be called UTF-8, rephrase the heading.

While at it, unbreak &&-chain in the test, and use test_config.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 12:00:57 -07:00
Michael S. Tsirkin
4cb46bddeb send-email: sanitize author when writing From line
sender is now sanitized, but we didn't sanitize author when checking
whether From: line is needed in the message body.

As a result git started writing duplicate From: lines when author
matched sender and has utf8 characters.

Reported-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 11:27:03 -07:00
Michael S. Tsirkin
f07075c297 send-email: add test for duplicate utf8 name
Verify that author name is not duplicated if it matches sender, even
if it is in utf8 (the test expects a failure that will be fixed in
the next patch).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-20 11:25:46 -07:00
Ramkumar Ramachandra
3cb8a5ff17 t/t5528-push-default: remove redundant test_config lines
The line

  test_config push.default upstream

appears unnecessarily in two tests, as the final test_push_failure sets
push.default before pushing anyway.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 19:11:34 -07:00
Antoine Pelisse
36617af7ed diff: add --ignore-blank-lines option
The goal of the patch is to introduce the GNU diff
-B/--ignore-blank-lines as closely as possible. The short option is not
available because it's already used for "break-rewrites".

When this option is used, git-diff will not create hunks that simply
add or remove empty lines, but will still show empty lines
addition/suppression if they are close enough to "valuable" changes.

There are two differences between this option and GNU diff -B option:
- GNU diff doesn't have "--inter-hunk-context", so this must be handled
- The following sequence looks like a bug (context is displayed twice):

    $ seq 5 >file1
    $ cat <<EOF >file2
    change
    1
    2

    3
    4
    5
    change
    EOF
    $ diff -u -B file1 file2
    --- file1	2013-06-08 22:13:04.471517834 +0200
    +++ file2	2013-06-08 22:13:23.275517855 +0200
    @@ -1,5 +1,7 @@
    +change
     1
     2
    +
     3
     4
     5
    @@ -3,3 +5,4 @@
     3
     4
     5
    +change

So here is a more thorough description of the option:
- real changes are interesting
- blank lines that are close enough (less than context size) to
interesting changes are considered interesting (recursive definition)
- "context" lines are used around each hunk of interesting changes
- If two hunks are separated by less than "inter-hunk-context", they
will be merged into one.

The implementation does the "interesting changes selection" in a single
pass.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 15:17:45 -07:00
Veres Lajos
f7e604ed39 random typofixes (committed missing a 't', successful missing an 's')
Signed-off-by: Veres Lajos <vlajos@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 11:31:33 -07:00
Ramkumar Ramachandra
eb4be1cbe2 sequencer: write useful reflog message for fast-forward
The following command

  $ git cherry-pick --ff b8bb3f

writes the following uninformative message to the reflog

  cherry-pick

Improve it to

  cherry-pick: fast-forward

Avoid hard-coding "cherry-pick" in fast_forward_to(), so the sequencer
is generic enough to support future actions.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 11:03:22 -07:00
Junio C Hamano
c3e2d18996 setup_reflog_action: document the rules for using GIT_REFLOG_ACTION
The set_reflog_action helper (in git-sh-setup) is designed to be
used once at the very top of a program, like this in "git am", for
example:

	set_reflog_action am

The helper function sets the given string to GIT_REFLOG_ACTION only
when GIT_REFLOG_ACTION is not yet set.  Thanks to this, "git am",
when run as the top-level program, will use "am" in GIT_REFLOG_ACTION
and the reflog entries made by whatever it does will record the
updates of refs done by "am".

Because of the conditional assignment, when "git am" is run as a
subprogram (i.e. an implementation detail) of "git rebase" that
already sets GIT_REFLOG_ACTION to its own name, the call in "git am"
to the helper function at the beginning will *not* have any effect.

So "git rebase" can do this:

	set_reflog_action rebase
	... do its own preparation, like checking out "onto" commit
        ... decide to do "format-patch" to "am" pipeline
        	git format-patch --stdout >mbox
		git am mbox

and the reflog entries made inside "git am" invocation will say
"rebase", not "am".

Calls to "git" commands that update refs would use GIT_REFLOG_ACTION
to record who did that update.  Most such calls in scripted Porcelains
do not define custom reflog message and rely on GIT_REFLOG_ACTION to
contain its (or its caller's, when it is called as a subprogram) name.

If a scripted Porcelain wants to record a custom reflog message for
a single invocation of "git" command (e.g. when "git rebase" uses
"git checkout" to detach HEAD at the commit a series is to be
replayed on), it needs to set GIT_REFLOG_ACTION to the custom
message and export it while calling the "git" command, but such an
assignment must be restricted to that single "git" invocation and
should not be left behind to affect later codepath.

Document the rules to avoid future confusion.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 10:54:00 -07:00
Michael Haggerty
fcb7c76274 resolve_ref_unsafe(): close race condition reading loose refs
We read loose references in two steps.  The code is roughly:

    lstat()
    if error ENOENT:
        loose ref is missing; look for corresponding packed ref
    else if S_ISLNK:
        readlink()
        if error:
            report failure
    else if S_ISDIR:
        report failure
    else
        open()
        if error:
            report failure
        read()

The problem is that the first filesystem call, to lstat(), is not
atomic with the second filesystem call, to readlink() or open().
Therefore it is possible for another process to change the file
between our two calls, for example:

* If the other process deletes the file, our second call will fail
  with ENOENT, which we *should* interpret as "loose ref is missing;
  look for corresponding packed ref".  This can arise if the other
  process is pack-refs; it might have just written a new packed-refs
  file containing the old contents of the reference then deleted the
  loose ref.

* If the other process changes a symlink into a plain file, our call
  to readlink() will fail with EINVAL, which we *should* respond to by
  trying to open() and read() the file.

The old code treats the reference as missing in both of these cases,
which is incorrect.

So instead, handle errors more selectively: if the result of
readline()/open() is a failure that is inconsistent with the result of
the previous lstat(), then something is fishy.  In this case jump back
and start over again with a fresh call to lstat().

One race is still possible and undetected: another process could
change the file from a regular file into a symlink between the call to
lstat and the call to open().  The open() call would silently follow
the symlink and not know that something is wrong.  This situation
could be detected in two ways:

* On systems that support O_NOFOLLOW, pass that option to the open().

* On other systems, call fstat() on the fd returned by open() and make
  sure that it agrees with the stat info from the original lstat().

However, we don't use symlinks anymore, so this situation is unlikely.
Moreover, it doesn't appear that treating a symlink as a regular file
would have grave consequences; after all, this is exactly how the code
handles non-relative symlinks.  So this commit leaves that race
unaddressed.

Note that this solves only the part of the race within
resolve_ref_unsafe. In the situation described above, we may still be
depending on a cached view of the packed-refs file; that race will be
dealt with in a future patch.

This problem was reported and diagnosed by Jeff King <peff@peff.net>,
and this solution is derived from his patch.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 10:23:04 -07:00
Michael Haggerty
2884c06ae7 resolve_ref_unsafe(): handle the case of an SHA-1 within loop
There is only one "break" statement within the loop, which jumps to
the code after the loop that handles the case of a file that holds a
SHA-1.  So move that code from below the loop into the if statement
where the break was previously located.  This makes the logic flow
more local.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 10:23:03 -07:00
Michael Haggerty
47f534bf92 resolve_ref_unsafe(): extract function handle_missing_loose_ref()
The nesting was getting a bit out of hand, and it's about to get
worse.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 10:23:03 -07:00
Brandon Casey
a94cf2cb7e http.c: don't rewrite the user:passwd string multiple times
Curl older than 7.17 (RHEL 4.X provides 7.12 and RHEL 5.X provides
7.15) requires that we manage any strings that we pass to it as
pointers.  So, we really shouldn't be modifying this strbuf after we
have passed it to curl.

Our interaction with curl is currently safe (before or after this
patch) since the pointer that is passed to curl is never invalidated;
it is repeatedly rewritten with the same sequence of characters but
the strbuf functions never need to allocate a larger string, so the
same memory buffer is reused.

This "guarantee" of safety is somewhat subtle and could be overlooked
by someone who may want to add a more complex handling of the username
and password.  So, let's stop modifying this strbuf after we have
passed it to curl, but also leave a note to describe the assumptions
that have been made about username/password lifetime and to draw
attention to the code.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-19 10:00:26 -07:00
Namhyung Kim
98c5c4ad01 name-rev: allow to specify a subpath for --refs option
When an user wants to filter specific ref using the --refs option,
the pattern needs to match the full ref, e.g. --refs=refs/tags/v1.*.

It'd be convenient to specify a subpath of ref pattern.  For
example, --refs=origin/* can find refs/remotes/origin/master by
searching the pattern against its substrings in turn:

  refs/remotes/origin/master
  remotes/origin/master
  origin/master

If it finds a match in a subpath, unambigous part of the ref path will
be removed in the output.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-18 12:02:02 -07:00
Thomas Rast
ae75342cff test-lib: rearrange start/end of test_expect_* and test_skip
This moves

* the early setup part from test_skip to a new function test_start_

* the final common parts of test_expect_* to a new function
  test_finish_

to make the next commit more obvious.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-18 11:15:14 -07:00
Thomas Rast
e6a6ddc93a test-lib: refactor $GIT_SKIP_TESTS matching
It's already used twice, and we will have more of the same kind of
matching in a minute.

Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-18 11:14:50 -07:00
Phil Hord
09b7e2204a fix "builtin-*" references to be "builtin/*"
Documentation and some comments still refer to files in builtin/
as 'builtin-*.[cho]'.  Update these to show the correct location.

Signed-off-by: Phil Hord <hordp@cisco.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Assisted-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-18 11:05:51 -07:00
Kevin Bracey
d7747bd5bc Documentation: Move "git diff <blob> <blob>"
The section describing "git diff <blob> <blob>" had been placed in a
position that disrupted the statement "This is synonymous to the
previous form".

Reorder to place this form after all the <commit>-using forms, and the
note applying to them. Also mention this form in the initial description
paragraph.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-18 09:33:12 -07:00