gitweb.git
Documentation/log: clarify what --raw meansMatthieu Moy Mon, 18 May 2015 17:55:57 +0000 (19:55 +0200)

Documentation/log: clarify what --raw means

There are several "raw formats", and describing --raw as "Generate the
raw format" in the documentation for git-log seems to imply that it
generates the raw *log* format.

Clarify the wording by saying "raw diff format" explicitly, and make a
special-case for "git log": "git log --raw" does not just change the
format, it shows something which is not shown by default.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pull: parse pull.ff as a bool or stringPaul Tan Mon, 18 May 2015 13:45:42 +0000 (21:45 +0800)

pull: parse pull.ff as a bool or string

Since b814da8 (pull: add pull.ff configuration, 2014-01-15) git-pull
supported setting --(no-)ff via the pull.ff configuration value.
However, as it only matches the string values of "true" and "false", it
does not support other boolean aliases such as "on", "off", "1", "0".
This is inconsistent with the merge.ff setting, which supports these
aliases.

Fix this by using the bool_or_string_config function to retrieve the
value of pull.ff.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pull: make pull.ff=true override merge.ffPaul Tan Mon, 18 May 2015 13:45:41 +0000 (21:45 +0800)

pull: make pull.ff=true override merge.ff

Since b814da8 (pull: add pull.ff configuration, 2014-01-15), running
git-pull with the configuration pull.ff=false or pull.ff=only is
equivalent to passing --no-ff and --ff-only to git-merge. However, if
pull.ff=true, no switch is passed to git-merge. This leads to the
confusing behavior where pull.ff=false or pull.ff=only is able to
override merge.ff, while pull.ff=true is unable to.

Fix this by adding the --ff switch if pull.ff=true, and add a test to
catch future regressions.

Furthermore, clarify in the documentation that pull.ff overrides
merge.ff.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pull: handle --log=<n>Paul Tan Mon, 18 May 2015 13:39:56 +0000 (21:39 +0800)

pull: handle --log=<n>

Since efb779f (merge, pull: add '--(no-)log' command line option,
2008-04-06) git-pull supported the (--no-)log switch and would pass it
to git-merge.

96e9420 (merge: Make '--log' an integer option for number of shortlog
entries, 2010-09-08) implemented support for the --log=<n> switch, which
would explicitly set the number of shortlog entries. However, git-pull
does not recognize this option, and will instead pass it to git-fetch,
leading to "unknown option" errors.

Fix this by matching --log=* in addition to --log and --no-log.

Implement a test for this use case.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sha1_file: pass empty buffer to index empty fileJim Hill Mon, 18 May 2015 00:41:45 +0000 (17:41 -0700)

sha1_file: pass empty buffer to index empty file

`git add` of an empty file with a filter pops complaints from
`copy_fd` about a bad file descriptor.

This traces back to these lines in sha1_file.c:index_core:

if (!size) {
ret = index_mem(sha1, NULL, size, type, path, flags);

The problem here is that content to be added to the index can be
supplied from an fd, or from a memory buffer, or from a pathname. This
call is supplying a NULL buffer pointer and a zero size.

Downstream logic takes the complete absence of a buffer to mean the
data is to be found elsewhere -- for instance, these, from convert.c:

if (params->src) {
write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
} else {
write_err = copy_fd(params->fd, child_process.in);
}

~If there's a buffer, write from that, otherwise the data must be coming
from an open fd.~

Perfectly reasonable logic in a routine that's going to write from
either a buffer or an fd.

So change `index_core` to supply an empty buffer when indexing an empty
file.

There's a patch out there that instead changes the logic quoted above to
take a `-1` fd to mean "use the buffer", but it seems to me that the
distinction between a missing buffer and an empty one carries intrinsic
semantics, where the logic change is adapting the code to handle
incorrect arguments.

Signed-off-by: Jim Hill <gjthill@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pack-protocol.txt: fix insconsistent spelling of "packfile"Patrick Steinhardt Sun, 17 May 2015 06:56:54 +0000 (08:56 +0200)

pack-protocol.txt: fix insconsistent spelling of "packfile"

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-unpack-objects.txt: fix inconsistent spelling of... Patrick Steinhardt Sun, 17 May 2015 06:56:53 +0000 (08:56 +0200)

git-unpack-objects.txt: fix inconsistent spelling of "packfile"

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-verify-pack.txt: fix inconsistent spelling of ... Patrick Steinhardt Sun, 17 May 2015 06:56:52 +0000 (08:56 +0200)

git-verify-pack.txt: fix inconsistent spelling of "packfile"

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http-backend: fix die recursion with custom handlerJeff King Fri, 15 May 2015 06:29:27 +0000 (02:29 -0400)

http-backend: fix die recursion with custom handler

When we die() in http-backend, we call a custom handler that
writes an HTTP 500 response to stdout, then reports the
error to stderr. Our routines for writing out the HTTP
response may themselves die, leading to us entering die()
again.

When it was originally written, that was OK; our custom
handler keeps a variable to notice this and does not
recurse. However, since cd163d4 (usage.c: detect recursion
in die routines and bail out immediately, 2012-11-14), the
main die() implementation detects recursion before we even
get to our custom handler, and bails without printing
anything useful.

We can handle this case by doing two things:

1. Installing a custom die_is_recursing handler that
allows us to enter up to one level of recursion. Only
the first call to our custom handler will try to write
out the error response. So if we die again, that is OK.
If we end up dying more than that, it is a sign that we
are in an infinite recursion.

2. Reporting the error to stderr before trying to write
out the HTTP response. In the current code, if we do
die() trying to write out the response, we'll exit
immediately from this second die(), and never get a
chance to output the original error (which is almost
certainly the more interesting one; the second die is
just going to be along the lines of "I tried to write
to stdout but it was closed").

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

lock_packed_refs(): allow retries when acquiring the... Michael Haggerty Mon, 11 May 2015 10:35:26 +0000 (12:35 +0200)

lock_packed_refs(): allow retries when acquiring the packed-refs lock

Currently, there is only one attempt to acquire any lockfile, and if
the lock is held by another process, the locking attempt fails
immediately.

This is not such a limitation for loose reference files. First, they
don't take long to rewrite. Second, most reference updates have a
known "old" value, so if another process is updating a reference at
the same moment that we are trying to lock it, then probably the
expected "old" value will not longer be valid, and the update will
fail anyway.

But these arguments do not hold for packed-refs:

* The packed-refs file can be large and take significant time to
rewrite.

* Many references are stored in a single packed-refs file, so it could
be that the other process was changing a different reference than
the one that we are interested in.

Therefore, it is much more likely for there to be spurious lock
conflicts in connection to the packed-refs file, resulting in
unnecessary command failures.

So, if the first attempt to lock the packed-refs file fails, continue
retrying for a configurable length of time before giving up. The
default timeout is 1 second.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

lockfile: allow file locking to be retried with a timeoutMichael Haggerty Mon, 11 May 2015 10:35:25 +0000 (12:35 +0200)

lockfile: allow file locking to be retried with a timeout

Currently, there is only one attempt to lock a file. If it fails, the
whole operation fails.

But it might sometimes be advantageous to try acquiring a file lock a
few times before giving up. So add a new function,
hold_lock_file_for_update_timeout(), that allows a timeout to be
specified. Make hold_lock_file_for_update() a thin wrapper around the
new function.

If timeout_ms is positive, then retry for at least that many
milliseconds to acquire the lock. On each failed attempt, use select()
to wait for a backoff time that increases quadratically (capped at 1
second) and has a random component to prevent two processes from
getting synchronized. If timeout_ms is negative, retry indefinitely.

In a moment we will switch to using the new function when locking
packed-refs.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

rerere: exit silently on "forget" when rerere is disabledJeff King Thu, 14 May 2015 19:20:52 +0000 (15:20 -0400)

rerere: exit silently on "forget" when rerere is disabled

If you run "git rerere forget foo" in a repository that does
not have rerere enabled, git hits an internal error:

$ git init -q
$ git rerere forget foo
fatal: BUG: attempt to commit unlocked object

The problem is that setup_rerere() will not actually take
the lock if the rerere system is disabled. We should notice
this and return early. We can return with a success code
here, because we know there is nothing to forget.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

pull: remove --tags error in no merge candidates casePaul Tan Wed, 13 May 2015 10:06:47 +0000 (18:06 +0800)

pull: remove --tags error in no merge candidates case

Since 441ed41 ("git pull --tags": error out with a better message.,
2007-12-28), git pull --tags would print a different error message if
git-fetch did not return any merge candidates:

It doesn't make sense to pull all tags; you probably meant:
git fetch --tags

This is because at that time, git-fetch --tags would override any
configured refspecs, and thus there would be no merge candidates. The
error message was thus introduced to prevent confusion.

However, since c5a84e9 (fetch --tags: fetch tags *in addition to*
other stuff, 2013-10-30), git fetch --tags would fetch tags in addition
to any configured refspecs. Hence, if any no merge candidates situation
occurs, it is not because --tags was set. As such, this special error
message is now irrelevant.

To prevent confusion, remove this error message.

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: convert AsciiDoc {?foo} to ifdef::foo[]Jeff King Thu, 14 May 2015 04:34:48 +0000 (00:34 -0400)

doc: convert AsciiDoc {?foo} to ifdef::foo[]

The former seems to just be syntactic sugar for the latter.
And as it's sugar that AsciiDoctor doesn't understand, it
would be nice to avoid it. Since there are only two spots,
and the resulting source is not significantly harder to
read, it's worth doing.

Note that this does slightly affect the generated HTML (it
has an extra newline), but the rendered result for both HTML
and docbook should be the same (since the newline is not
syntactically significant there).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Sync with 2.4.1Junio C Hamano Wed, 13 May 2015 21:34:46 +0000 (14:34 -0700)

Sync with 2.4.1

* maint:
Git 2.4.1

Git 2.4.1 v2.4.1Junio C Hamano Wed, 13 May 2015 21:11:43 +0000 (14:11 -0700)

Git 2.4.1

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'sb/line-log-plug-pairdiff-leak' into... Junio C Hamano Wed, 13 May 2015 21:05:56 +0000 (14:05 -0700)

Merge branch 'sb/line-log-plug-pairdiff-leak' into maint

* sb/line-log-plug-pairdiff-leak:
line-log.c: fix a memleak

Merge branch 'sb/test-bitmap-free-at-end' into maintJunio C Hamano Wed, 13 May 2015 21:05:55 +0000 (14:05 -0700)

Merge branch 'sb/test-bitmap-free-at-end' into maint

* sb/test-bitmap-free-at-end:
pack-bitmap.c: fix a memleak

Merge branch 'nd/t1509-chroot-test' into maintJunio C Hamano Wed, 13 May 2015 21:05:55 +0000 (14:05 -0700)

Merge branch 'nd/t1509-chroot-test' into maint

Correct test bitrot.

* nd/t1509-chroot-test:
t1509: update prepare script to be able to run t1509 in chroot again

Merge branch 'jk/type-from-string-gently' into maintJunio C Hamano Wed, 13 May 2015 21:05:54 +0000 (14:05 -0700)

Merge branch 'jk/type-from-string-gently' into maint

"git cat-file bl $blob" failed to barf even though there is no
object type that is "bl".

* jk/type-from-string-gently:
type_from_string_gently: make sure length matches

Merge branch 'ep/fix-test-lib-functions-report' into... Junio C Hamano Wed, 13 May 2015 21:05:52 +0000 (14:05 -0700)

Merge branch 'ep/fix-test-lib-functions-report' into maint

* ep/fix-test-lib-functions-report:
test-lib-functions.sh: fix the second argument to some helper functions

Merge branch 'cn/bom-in-gitignore' into maintJunio C Hamano Wed, 13 May 2015 21:05:51 +0000 (14:05 -0700)

Merge branch 'cn/bom-in-gitignore' into maint

Teach the codepaths that read .gitignore and .gitattributes files
that these files encoded in UTF-8 may have UTF-8 BOM marker at the
beginning; this makes it in line with what we do for configuration
files already.

* cn/bom-in-gitignore:
attr: skip UTF8 BOM at the beginning of the input file
config: use utf8_bom[] from utf.[ch] in git_parse_source()
utf8-bom: introduce skip_utf8_bom() helper
add_excludes_from_file: clarify the bom skipping logic
dir: allow a BOM at the beginning of exclude files

Merge branch 'jk/prune-mtime' into maintJunio C Hamano Wed, 13 May 2015 21:05:50 +0000 (14:05 -0700)

Merge branch 'jk/prune-mtime' into maint

Access to objects in repositories that borrow from another one on a
slow NFS server unnecessarily got more expensive due to recent code
becoming more cautious in a naive way not to lose objects to pruning.

* jk/prune-mtime:
sha1_file: only freshen packs once per run
sha1_file: freshen pack objects before loose
reachable: only mark local objects as recent

Merge branch 'jk/init-core-worktree-at-root' into maintJunio C Hamano Wed, 13 May 2015 21:05:49 +0000 (14:05 -0700)

Merge branch 'jk/init-core-worktree-at-root' into maint

We avoid setting core.worktree when the repository location is the
".git" directory directly at the top level of the working tree, but
the code misdetected the case in which the working tree is at the
root level of the filesystem (which arguably is a silly thing to
do, but still valid).

* jk/init-core-worktree-at-root:
init: don't set core.worktree when initializing /.git

log: do not shorten decoration names too earlyJunio C Hamano Wed, 13 May 2015 19:40:35 +0000 (12:40 -0700)

log: do not shorten decoration names too early

The DECORATE_SHORT_REFS option given to load_ref_decorations()
affects the way a copy of the refname is stored for each decorated
commit, and this forces later steps like current_pointed_by_HEAD()
to adjust their behaviour based on this initial settings.

Instead, we can always store the full refname and then shorten them
when producing the output.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

log: decorate HEAD with branch name under --decorate... Junio C Hamano Wed, 13 May 2015 17:25:18 +0000 (10:25 -0700)

log: decorate HEAD with branch name under --decorate=full, too

The previous step to teach "log --decorate" to show "HEAD -> master"
instead of "HEAD, master" when showing the commit at the tip of the
'master' branch, when the 'master' branch is checked out, did not
work for "log --decorate=full".

The commands in the "log" family prepare commit decorations for all
refs upfront, and the actual string used in a decoration depends on
how load_ref_decorations() is called very early in the process. By
default, "git log --decorate" stores names with common prefixes such
as "refs/heads" stripped; "git log --decorate=full" stores the full
refnames.

When the current_pointed_by_HEAD() function has to decide if "HEAD"
points at the branch a decoration describes, however, what was
passed to load_ref_decorations() to decide to strip (or keep) such a
common prefix is long lost. This makes it impossible to reliably
tell if a decoration that stores "refs/heads/master", for example,
is the 'master' branch (under "--decorate" with prefix omitted) or
'refs/heads/master' branch (under "--decorate=full").

Keep what was passed to load_ref_decorations() in a global next to
the global variable name_decoration, and use that to decide how to
match what was read from "HEAD" and what is in a decoration.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: put example URLs and emails inside literal backticksJeff King Wed, 13 May 2015 05:06:21 +0000 (01:06 -0400)

doc: put example URLs and emails inside literal backticks

This makes sure that AsciiDoc does not turn them into links.
Regular AsciiDoc does not catch these cases, but AsciiDoctor
does treat them as links.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: drop backslash quoting of some curly bracesJeff King Wed, 13 May 2015 05:02:22 +0000 (01:02 -0400)

doc: drop backslash quoting of some curly braces

Text like "{foo}" triggers an AsciiDoc attribute; we have to
write "\{foo}" to suppress this. But when the "foo" is not a
syntactically valid attribute, we can skip the quoting. This
makes the source nicer to read, and looks better under
Asciidoctor. With AsciiDoc itself, this patch produces no
changes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: convert \--option to --optionJeff King Wed, 13 May 2015 05:01:38 +0000 (01:01 -0400)

doc: convert \--option to --option

Older versions of AsciiDoc would convert the "--" in
"--option" into an emdash. According to 565e135
(Documentation: quote double-dash for AsciiDoc, 2011-06-29),
this is fixed in AsciiDoc 8.3.0. According to bf17126, we
don't support anything older than 8.4.1 anyway, so we no
longer need to worry about quoting.

Even though this does not change the output at all, there
are a few good reasons to drop the quoting:

1. It makes the source prettier to read.

2. We don't quote consistently, which may be confusing when
reading the source.

3. Asciidoctor does not like the quoting, and renders a
literal backslash.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc/add: reformat `--edit` optionJeff King Wed, 13 May 2015 04:58:51 +0000 (00:58 -0400)

doc/add: reformat `--edit` option

All of the other options in the list put short and long as
two separate headings.

We can also drop the backslashing of `--`. It isn't used
elsewhere and is unnecessary for modern asciidoc (plus it
confuses asciidoctor).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix length of underlined section-titleJeff King Wed, 13 May 2015 04:58:29 +0000 (00:58 -0400)

doc: fix length of underlined section-title

In AsciiDoc, it is OK to say:

this is my title
-------------------------

but AsciiDoctor is more strict. Let's match the underline to
the title (which also makes the source prettier to read).
The output from AsciiDoc is the same either way.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix hanging "+"-continuationJeff King Wed, 13 May 2015 04:58:16 +0000 (00:58 -0400)

doc: fix hanging "+"-continuation

In list content that wants to continue to a second
paragraph, the "+" continuation and subsequent paragraph
need to be left-aligned. Otherwise AsciiDoc seems to insert
only a linebreak.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix unquoted use of "{type}"Jeff King Wed, 13 May 2015 04:58:06 +0000 (00:58 -0400)

doc: fix unquoted use of "{type}"

Curly braces open an "attribute" in AsciiDoc; if there's no
such attribute, strange things may happen. In this case, the
unquoted "{type}" causes AsciiDoc to omit an entire line of
text from the output. We can fix it by putting the whole
phrase inside literal backticks (which also lets us get rid
of ugly backslash escaping).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix misrendering due to `single quote'Jeff King Wed, 13 May 2015 04:57:54 +0000 (00:57 -0400)

doc: fix misrendering due to `single quote'

AsciiDoc misparses some text that contains a `literal`
word followed by a fancy `single quote' word, and treats
everything from the start of the literal to the end of the
quote as a single-quoted phrase.

We can work around this by switching the latter to be a
literal, as well. In the first case, this is perhaps what
was intended anyway, as it makes us consistent with the the
earlier literals in the same paragraph. In the second, the
output is arguably better, as we will format our commit
references as <code> blocks.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix unmatched code fences in git-stripspaceJeff King Wed, 13 May 2015 02:15:56 +0000 (22:15 -0400)

doc: fix unmatched code fences in git-stripspace

The asciidoctor renderer is more picky than classic asciidoc,
and insists that the start and end of a code fence be the
same size.

Found with this hacky perl script:

foreach my $fn (@ARGV) {
open(my $fh, '<', $fn);
my ($fence, $fence_lineno, $prev);
while (<$fh>) {
chomp;
if (/^----+$/) {
if ($fence_lineno) {
if ($_ ne $fence) {
print "$fn:$fence_lineno:mismatched fence: ",
length($fence), " != ", length($_), "\n";
}
$fence_lineno = undef;
}
# hacky check to avoid title-underlining
elsif ($prev eq '' || $prev eq '+') {
$fence = $_;
$fence_lineno = $.;
}
}
$prev = $_;
}
}

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'mh/write-refs-sooner-2.3' into mh/write... Junio C Hamano Wed, 13 May 2015 04:28:54 +0000 (21:28 -0700)

Merge branch 'mh/write-refs-sooner-2.3' into mh/write-refs-sooner-2.4

* mh/write-refs-sooner-2.3:
ref_transaction_commit(): fix atomicity and avoid fd exhaustion
ref_transaction_commit(): remove the local flags variable
ref_transaction_commit(): inline call to write_ref_sha1()
rename_ref(): inline calls to write_ref_sha1() from this function
commit_ref_update(): new function, extracted from write_ref_sha1()
write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
update-ref: test handling large transactions properly

ref_transaction_commit(): fix atomicity and avoid fd... Michael Haggerty Fri, 24 Apr 2015 11:35:49 +0000 (13:35 +0200)

ref_transaction_commit(): fix atomicity and avoid fd exhaustion

The old code was roughly

for update in updates:
acquire locks and check old_sha
for update in updates:
if changing value:
write_ref_to_lockfile()
commit_ref_update()
for update in updates:
if deleting value:
unlink()
rewrite packed-refs file
for update in updates:
if reference still locked:
unlock_ref()

This has two problems.

Non-atomic updates
==================

The atomicity of the reference transaction depends on all pre-checks
being done in the first loop, before any changes have started being
committed in the second loop. The problem is that
write_ref_to_lockfile() (previously part of write_ref_sha1()), which
is called from the second loop, contains two more checks:

* It verifies that new_sha1 is a valid object

* If the reference being updated is a branch, it verifies that
new_sha1 points at a commit object (as opposed to a tag, tree, or
blob).

If either of these checks fails, the "transaction" is aborted during
the second loop. But this might happen after some reference updates
have already been permanently committed. In other words, the
all-or-nothing promise of "git update-ref --stdin" could be violated.

So these checks have to be moved to the first loop.

File descriptor exhaustion
==========================

The old code locked all of the references in the first loop, leaving
all of the lockfiles open until later loops. Since we might be
updating a lot of references, this could result in file descriptor
exhaustion.

The solution
============

After this patch, the code looks like

for update in updates:
acquire locks and check old_sha
if changing value:
write_ref_to_lockfile()
else:
close_ref()
for update in updates:
if changing value:
commit_ref_update()
for update in updates:
if deleting value:
unlink()
rewrite packed-refs file
for update in updates:
if reference still locked:
unlock_ref()

This fixes both problems:

1. The pre-checks in write_ref_to_lockfile() are now done in the first
loop, before any changes have been committed. If any of the checks
fails, the whole transaction can now be rolled back correctly.

2. All lockfiles are closed in the first loop immediately after they
are created (either by write_ref_to_lockfile() or by close_ref()).
This means that there is never more than one open lockfile at a
time, preventing file descriptor exhaustion.

To simplify the bookkeeping across loops, add a new REF_NEEDS_COMMIT
bit to update->flags, which keeps track of whether the corresponding
lockfile needs to be committed, as opposed to just unlocked. (Since
"struct ref_update" is internal to the refs module, this change is not
visible to external callers.)

This change fixes two tests in t1400.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref_transaction_commit(): remove the local flags variableMichael Haggerty Fri, 24 Apr 2015 11:35:48 +0000 (13:35 +0200)

ref_transaction_commit(): remove the local flags variable

Instead, work directly with update->flags. This has the advantage that
the REF_DELETING bit, set in the first loop, can be read in the second
loop instead of having to be recomputed. Plus, it was potentially
confusing having both update->flags and flags, which sometimes had
different values.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref_transaction_commit(): inline call to write_ref_sha1()Michael Haggerty Sat, 9 May 2015 15:29:20 +0000 (17:29 +0200)

ref_transaction_commit(): inline call to write_ref_sha1()

That was the last caller, so delete function write_ref_sha1().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

rename_ref(): inline calls to write_ref_sha1() from... Michael Haggerty Sat, 9 May 2015 15:20:39 +0000 (17:20 +0200)

rename_ref(): inline calls to write_ref_sha1() from this function

Most of what it does is unneeded from these call sites.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit_ref_update(): new function, extracted from write... Michael Haggerty Sat, 9 May 2015 15:18:36 +0000 (17:18 +0200)

commit_ref_update(): new function, extracted from write_ref_sha1()

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

write_ref_to_lockfile(): new function, extracted from... Michael Haggerty Fri, 24 Apr 2015 11:35:45 +0000 (13:35 +0200)

write_ref_to_lockfile(): new function, extracted from write_ref_sha1()

This is the first step towards separating the checking and writing of
the new reference value to committing the change.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZEStefan Beller Tue, 14 Apr 2015 22:25:07 +0000 (15:25 -0700)

t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE

During creation of the patch series our discussion we could have a
more descriptive name for the prerequisite for the test so it stays
unique when other limits of ulimit are introduced.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

update-ref: test handling large transactions properlyStefan Beller Tue, 14 Apr 2015 22:25:06 +0000 (15:25 -0700)

update-ref: test handling large transactions properly

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'mh/write-refs-sooner-2.2' into mh/write... Junio C Hamano Wed, 13 May 2015 04:26:09 +0000 (21:26 -0700)

Merge branch 'mh/write-refs-sooner-2.2' into mh/write-refs-sooner-2.3

* mh/write-refs-sooner-2.2:
ref_transaction_commit(): fix atomicity and avoid fd exhaustion
ref_transaction_commit(): remove the local flags variable
ref_transaction_commit(): inline call to write_ref_sha1()
rename_ref(): inline calls to write_ref_sha1() from this function
commit_ref_update(): new function, extracted from write_ref_sha1()
write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
update-ref: test handling large transactions properly

ref_transaction_commit(): fix atomicity and avoid fd... Michael Haggerty Sun, 10 May 2015 02:45:37 +0000 (04:45 +0200)

ref_transaction_commit(): fix atomicity and avoid fd exhaustion

The old code was roughly

for update in updates:
acquire locks and check old_sha
for update in updates:
if changing value:
write_ref_to_lockfile()
commit_ref_update()
for update in updates:
if deleting value:
unlink()
rewrite packed-refs file
for update in updates:
if reference still locked:
unlock_ref()

This has two problems.

Non-atomic updates
==================

The atomicity of the reference transaction depends on all pre-checks
being done in the first loop, before any changes have started being
committed in the second loop. The problem is that
write_ref_to_lockfile() (previously part of write_ref_sha1()), which
is called from the second loop, contains two more checks:

* It verifies that new_sha1 is a valid object

* If the reference being updated is a branch, it verifies that
new_sha1 points at a commit object (as opposed to a tag, tree, or
blob).

If either of these checks fails, the "transaction" is aborted during
the second loop. But this might happen after some reference updates
have already been permanently committed. In other words, the
all-or-nothing promise of "git update-ref --stdin" could be violated.

So these checks have to be moved to the first loop.

File descriptor exhaustion
==========================

The old code locked all of the references in the first loop, leaving
all of the lockfiles open until later loops. Since we might be
updating a lot of references, this could result in file descriptor
exhaustion.

The solution
============

After this patch, the code looks like

for update in updates:
acquire locks and check old_sha
if changing value:
write_ref_to_lockfile()
else:
close_ref()
for update in updates:
if changing value:
commit_ref_update()
for update in updates:
if deleting value:
unlink()
rewrite packed-refs file
for update in updates:
if reference still locked:
unlock_ref()

This fixes both problems:

1. The pre-checks in write_ref_to_lockfile() are now done in the first
loop, before any changes have been committed. If any of the checks
fails, the whole transaction can now be rolled back correctly.

2. All lockfiles are closed in the first loop immediately after they
are created (either by write_ref_to_lockfile() or by close_ref()).
This means that there is never more than one open lockfile at a
time, preventing file descriptor exhaustion.

To simplify the bookkeeping across loops, add a new REF_NEEDS_COMMIT
bit to update->flags, which keeps track of whether the corresponding
lockfile needs to be committed, as opposed to just unlocked. (Since
"struct ref_update" is internal to the refs module, this change is not
visible to external callers.)

This change fixes two tests in t1400.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref_transaction_commit(): remove the local flags variableMichael Haggerty Sun, 10 May 2015 02:45:36 +0000 (04:45 +0200)

ref_transaction_commit(): remove the local flags variable

Instead, work directly with update->flags. This has the advantage that
the REF_DELETING bit, set in the first loop, can be read in the second
loop instead of having to be recomputed. Plus, it was potentially
confusing having both update->flags and flags, which sometimes had
different values.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref_transaction_commit(): inline call to write_ref_sha1()Michael Haggerty Sun, 10 May 2015 02:45:35 +0000 (04:45 +0200)

ref_transaction_commit(): inline call to write_ref_sha1()

And remove the function write_ref_sha1(), as it is no longer used.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

rename_ref(): inline calls to write_ref_sha1() from... Michael Haggerty Sun, 10 May 2015 02:45:34 +0000 (04:45 +0200)

rename_ref(): inline calls to write_ref_sha1() from this function

Most of what it does is unneeded from these call sites.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit_ref_update(): new function, extracted from write... Michael Haggerty Sun, 10 May 2015 02:45:33 +0000 (04:45 +0200)

commit_ref_update(): new function, extracted from write_ref_sha1()

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

write_ref_to_lockfile(): new function, extracted from... Michael Haggerty Sun, 10 May 2015 02:45:32 +0000 (04:45 +0200)

write_ref_to_lockfile(): new function, extracted from write_ref_sha1()

This is the first step towards separating the checking and writing of
the new reference value to committing the change.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZEStefan Beller Sun, 10 May 2015 02:45:31 +0000 (04:45 +0200)

t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE

During creation of the patch series, our discussion revealed that
we could have a more descriptive name for the prerequisite for the
test so it stays unique when other limits of ulimit are introduced.

Let's rename the existing ulimit about setting the stack size to
a more explicit ULIMIT_STACK_SIZE.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

add: check return value of launch_editorJeff King Wed, 13 May 2015 01:21:58 +0000 (21:21 -0400)

add: check return value of launch_editor

When running "add -e", if launching the editor fails, we do
not notice and continue as if the output is what the user
asked for. The likely case is that the editor did not touch
the contents at all, and we end up adding everything.

Reported-by: Russ Cox <rsc@golang.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

completion: simplify query for config variablesSZEDER Gábor Sun, 10 May 2015 12:50:18 +0000 (14:50 +0200)

completion: simplify query for config variables

To get the name of all config variables in a given section we perform a
'git config --get-regex' query for all config variables containing the
name of that section, and then filter its output through a case statement
to throw away those that though contain but don't start with the given
section.

Modify the regex to match only at the beginning, so the case statement
becomes unnecessary and we can get rid of it. Add a test to check that a
match in the middle doesn't fool us.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

completion: add a helper function to get config variablesSZEDER Gábor Sun, 10 May 2015 12:50:17 +0000 (14:50 +0200)

completion: add a helper function to get config variables

Currently there are a few completion functions that perform similar 'git
config' queries and filtering to get config variable names: the completion
of pretty aliases, aliases, and remote groups for 'git remote update'.

Unify those 'git config' queries in a helper function to eliminate code
duplication.

Though the helper functions to get pretty aliases and alieses are reduced
to mere one-liner wrappers around the newly added function, keep these
helpers still, because users' completion functions out there might depend
on them. And they keep their callers a tad easier to read, too.

Add tests for the pretty alias and alias helper to show that they work
as before; not for the remote groups query, though, because that's not
extracted into a helper function and it's not worth the effort to do so
for a sole callsite.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

doc: fix unmatched code fencesJean-Noel Avila Tue, 12 May 2015 17:23:20 +0000 (19:23 +0200)

doc: fix unmatched code fences

This mismatch upsets the renderer on git-scm.com.

Signed-off-by: Jean-Noel Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'maint'Junio C Hamano Mon, 11 May 2015 21:39:39 +0000 (14:39 -0700)

Merge branch 'maint'

* maint:
Git 2.3.8

Sync with 2.3.8Junio C Hamano Mon, 11 May 2015 21:39:28 +0000 (14:39 -0700)

Sync with 2.3.8

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Git 2.3.8 v2.3.8Junio C Hamano Mon, 11 May 2015 21:36:31 +0000 (14:36 -0700)

Git 2.3.8

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'mm/usage-log-l-can-take-regex' into maint-2.3Junio C Hamano Mon, 11 May 2015 21:34:01 +0000 (14:34 -0700)

Merge branch 'mm/usage-log-l-can-take-regex' into maint-2.3

Documentation fix.

* mm/usage-log-l-can-take-regex:
log -L: improve error message on malformed argument
Documentation: change -L:<regex> to -L:<funcname>

Merge branch 'jc/diff-no-index-d-f' into maint-2.3Junio C Hamano Mon, 11 May 2015 21:34:00 +0000 (14:34 -0700)

Merge branch 'jc/diff-no-index-d-f' into maint-2.3

The usual "git diff" when seeing a file turning into a directory
showed a patchset to remove the file and create all files in the
directory, but "git diff --no-index" simply refused to work. Also,
when asked to compare a file and a directory, imitate POSIX "diff"
and compare the file with the file with the same name in the
directory, instead of refusing to run.

* jc/diff-no-index-d-f:
diff-no-index: align D/F handling with that of normal Git
diff-no-index: DWIM "diff D F" into "diff D/F F"

Merge branch 'oh/fix-config-default-user-name-section... Junio C Hamano Mon, 11 May 2015 21:33:59 +0000 (14:33 -0700)

Merge branch 'oh/fix-config-default-user-name-section' into maint-2.3

The default $HOME/.gitconfig file created upon "git config --global"
that edits it had incorrectly spelled user.name and user.email
entries in it.

* oh/fix-config-default-user-name-section:
config: fix settings in default_user_config template

Merge branch 'jc/epochtime-wo-tz' into maint-2.3Junio C Hamano Mon, 11 May 2015 21:33:58 +0000 (14:33 -0700)

Merge branch 'jc/epochtime-wo-tz' into maint-2.3

"git commit --date=now" or anything that relies on approxidate lost
the daylight-saving-time offset.

* jc/epochtime-wo-tz:
parse_date_basic(): let the system handle DST conversion
parse_date_basic(): return early when given a bogus timestamp

Second batch for 2.5 cycleJunio C Hamano Mon, 11 May 2015 21:31:28 +0000 (14:31 -0700)

Second batch for 2.5 cycle

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Merge branch 'pt/xdg-config-path'Junio C Hamano Mon, 11 May 2015 21:24:01 +0000 (14:24 -0700)

Merge branch 'pt/xdg-config-path'

Code clean-up for xdg configuration path support.

* pt/xdg-config-path:
path.c: remove home_config_paths()
git-config: replace use of home_config_paths()
git-commit: replace use of home_config_paths()
credential-store.c: replace home_config_paths() with xdg_config_home()
dir.c: replace home_config_paths() with xdg_config_home()
attr.c: replace home_config_paths() with xdg_config_home()
path.c: implement xdg_config_home()

Merge branch 'ep/do-not-feed-a-pointer-to-array-size'Junio C Hamano Mon, 11 May 2015 21:24:00 +0000 (14:24 -0700)

Merge branch 'ep/do-not-feed-a-pointer-to-array-size'

Catch a programmer mistake to feed a pointer not an array to
ARRAY_SIZE() macro, by using a couple of GCC extensions.

* ep/do-not-feed-a-pointer-to-array-size:
git-compat-util.h: implement a different ARRAY_SIZE macro for for safely deriving the size of array

Merge branch 'jc/hash-object'Junio C Hamano Mon, 11 May 2015 21:23:59 +0000 (14:23 -0700)

Merge branch 'jc/hash-object'

"hash-object --literally" introduced in v2.2 was not prepared to
take a really long object type name.

* jc/hash-object:
write_sha1_file(): do not use a separate sha1[] array
t1007: add hash-object --literally tests
hash-object --literally: fix buffer overrun with extra-long object type
git-hash-object.txt: document --literally option

Merge branch 'sb/prefix-path-free-results'Junio C Hamano Mon, 11 May 2015 21:23:57 +0000 (14:23 -0700)

Merge branch 'sb/prefix-path-free-results'

Code clean-up (not a leak-fix).

* sb/prefix-path-free-results:
prefix_path(): unconditionally free results in the callers

Merge branch 'sg/completion-no-redundant-all-command... Junio C Hamano Mon, 11 May 2015 21:23:57 +0000 (14:23 -0700)

Merge branch 'sg/completion-no-redundant-all-command-list'

Code simplification.

* sg/completion-no-redundant-all-command-list:
completion: remove redundant __git_compute_all_commands() call

Merge branch 'sg/complete-decorate-full-not-long'Junio C Hamano Mon, 11 May 2015 21:23:55 +0000 (14:23 -0700)

Merge branch 'sg/complete-decorate-full-not-long'

The completion for "log --decorate=" parameter value was incorrect.

* sg/complete-decorate-full-not-long:
completion: fix and update 'git log --decorate=' options

Merge branch 'jk/filter-branch-use-of-sed-on-incomplete... Junio C Hamano Mon, 11 May 2015 21:23:54 +0000 (14:23 -0700)

Merge branch 'jk/filter-branch-use-of-sed-on-incomplete-line'

"filter-branch" corrupted commit log message that ends with an
incomplete line on platforms with some "sed" implementations that
munge such a line. Work it around by avoiding to use "sed".

* jk/filter-branch-use-of-sed-on-incomplete-line:
filter-branch: avoid passing commit message through sed

Merge branch 'jc/daemon-no-ipv6-for-2.4.1'Junio C Hamano Mon, 11 May 2015 21:23:53 +0000 (14:23 -0700)

Merge branch 'jc/daemon-no-ipv6-for-2.4.1'

"git daemon" fails to build from the source under NO_IPV6
configuration (regression in 2.4).

* jc/daemon-no-ipv6-for-2.4.1:
daemon: unbreak NO_IPV6 build regression

Merge branch 'jn/clean-use-error-not-fprintf-on-stderr'Junio C Hamano Mon, 11 May 2015 21:23:52 +0000 (14:23 -0700)

Merge branch 'jn/clean-use-error-not-fprintf-on-stderr'

Some error messages in "git config" were emitted without calling
the usual error() facility.

* jn/clean-use-error-not-fprintf-on-stderr:
config: use error() instead of fprintf(stderr, ...)

Merge branch 'tb/blame-resurrect-convert-to-git'Junio C Hamano Mon, 11 May 2015 21:23:52 +0000 (14:23 -0700)

Merge branch 'tb/blame-resurrect-convert-to-git'

Some time ago, "git blame" (incorrectly) lost the convert_to_git()
call when synthesizing a fake "tip" commit that represents the
state in the working tree, which broke folks who record the history
with LF line ending to make their project portabile across
platforms while terminating lines in their working tree files with
CRLF for their platform.

* tb/blame-resurrect-convert-to-git:
blame: CRLF in the working tree and LF in the repo

Merge branch 'va/fix-git-p4-tests'Junio C Hamano Mon, 11 May 2015 21:23:51 +0000 (14:23 -0700)

Merge branch 'va/fix-git-p4-tests'

* va/fix-git-p4-tests:
git-p4: t9814: prevent --chain-lint failure

Merge branch 'ld/p4-case-fold'Junio C Hamano Mon, 11 May 2015 21:23:50 +0000 (14:23 -0700)

Merge branch 'ld/p4-case-fold'

* ld/p4-case-fold:
git-p4: add failing tests for case-folding p4d

Merge branch 'jk/rebase-quiet-noop'Junio C Hamano Mon, 11 May 2015 21:23:49 +0000 (14:23 -0700)

Merge branch 'jk/rebase-quiet-noop'

"git rebase --quiet" was not quite quiet when there is nothing to
do.

* jk/rebase-quiet-noop:
rebase: silence "git checkout" for noop rebase

Merge branch 'va/p4-client-path'Junio C Hamano Mon, 11 May 2015 21:23:48 +0000 (14:23 -0700)

Merge branch 'va/p4-client-path'

git p4 attempts to better handle branches in Perforce.

* va/p4-client-path:
git-p4: improve client path detection when branches are used
t9801: check git-p4's branch detection with client spec enabled

Merge branch 'mm/add-p-split-error'Junio C Hamano Mon, 11 May 2015 21:23:47 +0000 (14:23 -0700)

Merge branch 'mm/add-p-split-error'

When "add--interactive" splits a hunk into two overlapping hunks
and then let the user choose only one, it sometimes feeds an
incorrect patch text to "git apply". Add tests to demonstrate
this.

I have a slight suspicion that this may be $gmane/87202 coming back
and biting us (I seem to have said "let's run with this and see
what happens" back then).

* mm/add-p-split-error:
stash -p: demonstrate failure of split with mixed y/n
t3904-stash-patch: factor PERL prereq at the top of the file
t3904-stash-patch: fix test description
add -p: demonstrate failure when running 'edit' after a split
t3701-add-interactive: simplify code

Merge branch 'tb/t0027-crlf'Junio C Hamano Mon, 11 May 2015 21:23:47 +0000 (14:23 -0700)

Merge branch 'tb/t0027-crlf'

More line-ending tests.

* tb/t0027-crlf:
t0027: Add repoMIX and LF_nul
t0027: support NATIVE_CRLF platforms
t0027: cleanup: rename functions; avoid non-leading TABs

Merge branch 'ls/p4-changes-block-size'Junio C Hamano Mon, 11 May 2015 21:23:46 +0000 (14:23 -0700)

Merge branch 'ls/p4-changes-block-size'

"git p4" learned "--changes-block-size <n>" to read the changes in
chunks from Perforce, instead of making one call to "p4 changes"
that may trigger "too many rows scanned" error from Perforce.

* ls/p4-changes-block-size:
git-p4: use -m when running p4 changes

Merge branch 'jc/plug-fmt-merge-msg-leak'Junio C Hamano Mon, 11 May 2015 21:23:45 +0000 (14:23 -0700)

Merge branch 'jc/plug-fmt-merge-msg-leak'

* jc/plug-fmt-merge-msg-leak:
fmt-merge-msg: plug small leak of commit buffer

Merge branch 'nd/slim-index-pack-memory-usage'Junio C Hamano Mon, 11 May 2015 21:23:44 +0000 (14:23 -0700)

Merge branch 'nd/slim-index-pack-memory-usage'

Memory usage of "git index-pack" has been trimmed by tens of
per-cent.

* nd/slim-index-pack-memory-usage:
index-pack: kill union delta_base to save memory
index-pack: reduce object_entry size to save memory

Merge branch 'jk/still-interesting'Junio C Hamano Mon, 11 May 2015 21:23:43 +0000 (14:23 -0700)

Merge branch 'jk/still-interesting'

"git rev-list --objects $old --not --all" to see if everything that
is reachable from $old is already connected to the existing refs
was very inefficient.

* jk/still-interesting:
limit_list: avoid quadratic behavior from still_interesting

Merge branch 'jk/reading-packed-refs'Junio C Hamano Mon, 11 May 2015 21:23:42 +0000 (14:23 -0700)

Merge branch 'jk/reading-packed-refs'

An earlier rewrite to use strbuf_getwholeline() instead of fgets(3)
to read packed-refs file revealed that the former is unacceptably
inefficient.

* jk/reading-packed-refs:
t1430: add another refs-escape test
read_packed_refs: avoid double-checking sane refs
strbuf_getwholeline: use getdelim if it is available
strbuf_getwholeline: avoid calling strbuf_grow
strbuf_addch: avoid calling strbuf_grow
config: use getc_unlocked when reading from file
strbuf_getwholeline: use getc_unlocked
git-compat-util: add fallbacks for unlocked stdio
strbuf_getwholeline: use getc macro

Merge branch 'lm/squelch-bg-progress'Junio C Hamano Mon, 11 May 2015 21:23:42 +0000 (14:23 -0700)

Merge branch 'lm/squelch-bg-progress'

Many long-running operations show progress eye-candy, even when
they are later backgrounded. Hide the eye-candy when the process
is sent to the background instead.

* lm/squelch-bg-progress:
compat/mingw: stubs for getpgid() and tcgetpgrp()
progress: no progress in background

Merge branch 'jk/sha1-file-reduce-useless-warnings'Junio C Hamano Mon, 11 May 2015 21:23:40 +0000 (14:23 -0700)

Merge branch 'jk/sha1-file-reduce-useless-warnings'

* jk/sha1-file-reduce-useless-warnings:
sha1_file: squelch "packfile cannot be accessed" warnings

Merge branch 'nd/multiple-work-trees'Junio C Hamano Mon, 11 May 2015 21:23:39 +0000 (14:23 -0700)

Merge branch 'nd/multiple-work-trees'

A replacement for contrib/workdir/git-new-workdir that does not
rely on symbolic links and make sharing of objects and refs safer
by making the borrowee and borrowers aware of each other.

* nd/multiple-work-trees: (41 commits)
prune --worktrees: fix expire vs worktree existence condition
t1501: fix test with split index
t2026: fix broken &&-chain
t2026 needs procondition SANITY
git-checkout.txt: a note about multiple checkout support for submodules
checkout: add --ignore-other-wortrees
checkout: pass whole struct to parse_branchname_arg instead of individual flags
git-common-dir: make "modules/" per-working-directory directory
checkout: do not fail if target is an empty directory
t2025: add a test to make sure grafts is working from a linked checkout
checkout: don't require a work tree when checking out into a new one
git_path(): keep "info/sparse-checkout" per work-tree
count-objects: report unused files in $GIT_DIR/worktrees/...
gc: support prune --worktrees
gc: factor out gc.pruneexpire parsing code
gc: style change -- no SP before closing parenthesis
checkout: clean up half-prepared directories in --to mode
checkout: reject if the branch is already checked out elsewhere
prune: strategies for linked checkouts
checkout: support checking out into a new working directory
...

Merge branch 'pt/credential-xdg'Junio C Hamano Mon, 11 May 2015 21:23:38 +0000 (14:23 -0700)

Merge branch 'pt/credential-xdg'

Tweak the sample "store" backend of the credential helper to honor
XDG configuration file locations when specified.

* pt/credential-xdg:
t0302: "unreadable" test needs POSIXPERM
t0302: test credential-store support for XDG_CONFIG_HOME
git-credential-store: support XDG_CONFIG_HOME
git-credential-store: support multiple credential files

reflog_expire(): integrate lock_ref_sha1_basic() errors... Michael Haggerty Mon, 11 May 2015 15:25:20 +0000 (17:25 +0200)

reflog_expire(): integrate lock_ref_sha1_basic() errors into ours

Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting two separate error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

ref_transaction_commit(): delete extra "the" from error... Michael Haggerty Mon, 11 May 2015 15:25:19 +0000 (17:25 +0200)

ref_transaction_commit(): delete extra "the" from error message

While we are in the area, let's remove a superfluous definite article
from the error message that is emitted when the reference cannot be
locked. This improves how it reads and makes it a bit shorter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

ref_transaction_commit(): provide better error messagesMichael Haggerty Mon, 11 May 2015 15:25:18 +0000 (17:25 +0200)

ref_transaction_commit(): provide better error messages

Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting one error messages to stderr immediately and returning a
second to our caller.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

rename_ref(): integrate lock_ref_sha1_basic() errors... Michael Haggerty Mon, 11 May 2015 15:25:17 +0000 (17:25 +0200)

rename_ref(): integrate lock_ref_sha1_basic() errors into ours

Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting two separate error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

lock_ref_sha1_basic(): improve diagnostics for ref... Michael Haggerty Mon, 11 May 2015 15:25:16 +0000 (17:25 +0200)

lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts

If there is a failure to lock a reference that is likely caused by a
D/F conflict (e.g., trying to lock "refs/foo/bar" when reference
"refs/foo" already exists), invoke verify_refname_available() to try
to generate a more helpful error message.

That function might not detect an error. For example, some
non-reference file might be blocking the deletion of an
otherwise-empty directory tree, or there might be a race with another
process that just deleted the offending reference. In such cases,
generate the strerror-based error message like before.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

lock_ref_sha1_basic(): report errors via a "struct... Michael Haggerty Mon, 11 May 2015 15:25:15 +0000 (17:25 +0200)

lock_ref_sha1_basic(): report errors via a "struct strbuf *err"

For now, change the callers to spew the error to stderr like before.
But soon we will change them to incorporate the reason for the failure
into their own error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

verify_refname_available(): report errors via a "struct... Michael Haggerty Mon, 11 May 2015 15:25:14 +0000 (17:25 +0200)

verify_refname_available(): report errors via a "struct strbuf *err"

It shouldn't be spewing errors directly to stderr.

For now, change its callers to spew the errors to stderr.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

verify_refname_available(): rename functionMichael Haggerty Mon, 11 May 2015 15:25:13 +0000 (17:25 +0200)

verify_refname_available(): rename function

Rename is_refname_available() to verify_refname_available() and change
its return value from 1 for success to 0 for success, to be consistent
with our error-handling convention. In a moment it will also get a
"struct strbuf *err" parameter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

refs: check for D/F conflicts among refs created in... Michael Haggerty Mon, 11 May 2015 15:25:12 +0000 (17:25 +0200)

refs: check for D/F conflicts among refs created in a transaction

If two references that D/F conflict (e.g., "refs/foo" and
"refs/foo/bar") are created in a single transaction, the old code
discovered the problem only after the "commit" phase of
ref_transaction_commit() had already begun. This could leave some
references updated and others not, which violates the promise of
atomicity.

Instead, check for such conflicts during the "locking" phase:

* Teach is_refname_available() to take an "extras" parameter that can
contain extra reference names with which the specified refname must
not conflict.

* Change lock_ref_sha1_basic() to take an "extras" parameter, which it
passes through to is_refname_available().

* Change ref_transaction_commit() to pass "affected_refnames" to
lock_ref_sha1_basic() as its "extras" argument.

This change fixes a test case in t1404.

This code is a bit stricter than it needs to be. We could conceivably
allow reference "refs/foo/bar" to be created in the same transaction
as "refs/foo" is deleted (or vice versa). But that would be
complicated to implement, because it is not possible to lock
"refs/foo/bar" while "refs/foo" exists as a loose reference, but on
the other hand we don't want to delete some references before adding
others (because that could leave a gap during which required objects
are unreachable). There is also a complication that reflog files'
paths can conflict.

Any less-strict implementation would probably require tricks like the
packing of all references before the start of the real transaction, or
the use of temporary intermediate reference names.

So for now let's accept too-strict checks. Some reference update
transactions will be rejected unnecessarily, but they will be rejected
in their entirety rather than leaving the repository in an
intermediate state, as would happen now.

Please note that there is still one kind of D/F conflict that is *not*
handled correctly. If two processes are running at the same time, and
one tries to create "refs/foo" at the same time that the other tries
to create "refs/foo/bar", then they can race with each other. Both
processes can obtain their respective locks ("refs/foo.lock" and
"refs/foo/bar.lock"), proceed to the "commit" phase of
ref_transaction_commit(), and then the slower process will discover
that it cannot rename its lockfile into place (after possibly having
committed changes to other references). There appears to be no way to
fix this race without changing the locking policy, which in turn would
require a change to *all* Git clients.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

ref_transaction_commit(): use a string_list for detecti... Michael Haggerty Mon, 11 May 2015 15:25:11 +0000 (17:25 +0200)

ref_transaction_commit(): use a string_list for detecting duplicates

Detect duplicates by storing the reference names in a string_list and
sorting that, instead of sorting the ref_updates directly.

* In a moment the string_list will be used for another purpose, too.

* This removes the need for the custom comparison function
ref_update_compare().

* This means that we can carry out the updates in the order that the
user specified them instead of reordering them. This might be handy
someday if, we want to permit multiple updates to a single reference
as long as they are compatible with each other.

Note: we can't use string_list_remove_duplicates() to check for
duplicates, because we need to know the name of the reference that
appeared multiple times, to be used in the error message.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>

is_refname_available(): use dirname in first loopMichael Haggerty Mon, 11 May 2015 15:25:10 +0000 (17:25 +0200)

is_refname_available(): use dirname in first loop

In the first loop (over prefixes of refname), use dirname to keep
track of the current prefix. This is not an improvement in itself, but
in a moment we will start using dirname for a role where a
NUL-terminated string is needed.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>