Commit Graph

9654 Commits

Author SHA1 Message Date
Junio C Hamano
b4d6280e2f Merge branch 'jk/maint-for-each-packed-object' into jk/cat-file-batch-all
* jk/maint-for-each-packed-object:
  for_each_packed_object: automatically open pack index
2015-06-22 14:54:15 -07:00
Jeff King
f813e9ea5f for_each_packed_object: automatically open pack index
When for_each_packed_object is called, we call
prepare_packed_git() to make sure we have the actual list of
packs. But the latter does not actually open the pack
indices, meaning that pack->nr_objects may simply be 0 if
the pack has not otherwise been used since the program
started.

In practice, this didn't come up for the current callers,
because they iterate the packed objects only after iterating
all reachable objects (so for it to matter you would have to
have a pack consisting only of unreachable objects). But it
is a dangerous and confusing interface that should be fixed
for future callers.

Note that we do not end the iteration when a pack cannot be
opened, but we do return an error. That lets you complete
the iteration even in actively-repacked repository where an
.idx file may racily go away, but it also lets callers know
that they may not have gotten the complete list (which the
current reachability-check caller does care about).

We have to tweak one of the prune tests due to the changed
return value; an earlier test creates bogus .idx files and
does not clean them up. Having to make this tweak is a good
thing; it means we will not prune in a broken repository,
and the test confirms that we do not negatively impact a
more lenient caller, count-objects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:53:58 -07:00
Junio C Hamano
67f0b6f3b2 Merge branch 'dt/cat-file-follow-symlinks'
"git cat-file --batch(-check)" learned the "--follow-symlinks"
option that follows an in-tree symbolic link when asked about an
object via extended SHA-1 syntax, e.g. HEAD:RelNotes that points at
Documentation/RelNotes/2.5.0.txt.  With the new option, the command
behaves as if HEAD:Documentation/RelNotes/2.5.0.txt was given as
input instead.

* dt/cat-file-follow-symlinks:
  cat-file: add --follow-symlinks to --batch
  sha1_name: get_sha1_with_context learns to follow symlinks
  tree-walk: learn get_tree_entry_follow_symlinks
2015-06-01 12:45:16 -07:00
Junio C Hamano
f693bb0bb0 Merge branch 'jk/stash-options'
Make "git stash something --help" error out, so that users can
safely say "git stash drop --help".

* jk/stash-options:
  stash: recognize "--help" for subcommands
  stash: complain about unknown flags
2015-06-01 12:45:14 -07:00
Junio C Hamano
152722f155 Merge branch 'jh/filter-empty-contents'
The clean/smudge interface did not work well when filtering an
empty contents (failed and then passed the empty input through).
It can be argued that a filter that produces anything but empty for
an empty input is nonsense, but if the user wants to do strange
things, then why not?

* jh/filter-empty-contents:
  sha1_file: pass empty buffer to index empty file
2015-06-01 12:45:11 -07:00
Junio C Hamano
777e75b605 Merge branch 'jk/http-backend-deadlock'
Communication between the HTTP server and http_backend process can
lead to a dead-lock when relaying a large ref negotiation request.
Diagnose the situation better, and mitigate it by reading such a
request first into core (to a reasonable limit).

* jk/http-backend-deadlock:
  http-backend: spool ref negotiation requests to buffer
  t5551: factor out tag creation
  http-backend: fix die recursion with custom handler
2015-06-01 12:45:09 -07:00
Junio C Hamano
77bd3ea9f5 Merge branch 'nd/untracked-cache'
* nd/untracked-cache:
  t7063: hide stderr from setup inside prereq
2015-05-27 13:14:38 -07:00
Jeff King
fa73a582b5 t7063: hide stderr from setup inside prereq
When t7063 starts, it runs "update-index --untracked-cache"
to see if we support the untracked cache. Its output goes
straight to stderr, even if the test is not run with "-v".
Let's wrap it in a prereq that will hide the output by
default, but show it with "-v".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 13:14:29 -07:00
Junio C Hamano
38ccaf93bb Merge branch 'nd/untracked-cache'
Teach the index to optionally remember already seen untracked files
to speed up "git status" in a working tree with tons of cruft.

* nd/untracked-cache: (24 commits)
  git-status.txt: advertisement for untracked cache
  untracked cache: guard and disable on system changes
  mingw32: add uname()
  t7063: tests for untracked cache
  update-index: test the system before enabling untracked cache
  update-index: manually enable or disable untracked cache
  status: enable untracked cache
  untracked-cache: temporarily disable with $GIT_DISABLE_UNTRACKED_CACHE
  untracked cache: mark index dirty if untracked cache is updated
  untracked cache: print stats with $GIT_TRACE_UNTRACKED_STATS
  untracked cache: avoid racy timestamps
  read-cache.c: split racy stat test to a separate function
  untracked cache: invalidate at index addition or removal
  untracked cache: load from UNTR index extension
  untracked cache: save to an index extension
  ewah: add convenient wrapper ewah_serialize_strbuf()
  untracked cache: don't open non-existent .gitignore
  untracked cache: mark what dirs should be recursed/saved
  untracked cache: record/validate dir mtime and reuse cached output
  untracked cache: make a wrapper around {open,read,close}dir()
  ...
2015-05-26 13:24:46 -07:00
Junio C Hamano
22a1ae6ef2 Merge branch 'pt/pull-ff-vs-merge-ff'
The pull.ff configuration was supposed to override the merge.ff
configuration, but it didn't.

* pt/pull-ff-vs-merge-ff:
  pull: parse pull.ff as a bool or string
  pull: make pull.ff=true override merge.ff
2015-05-26 13:24:44 -07:00
Junio C Hamano
14230580af Merge branch 'pt/pull-log-n'
"git pull --log" and "git pull --no-log" worked as expected, but
"git pull --log=20" did not.

* pt/pull-log-n:
  pull: handle --log=<n>
2015-05-26 13:24:43 -07:00
Junio C Hamano
636614f337 Merge branch 'jk/http-backend-deadlock-2.3' into jk/http-backend-deadlock
* jk/http-backend-deadlock-2.3:
  http-backend: spool ref negotiation requests to buffer
  t5551: factor out tag creation
  http-backend: fix die recursion with custom handler
2015-05-25 20:44:42 -07:00
Junio C Hamano
7419a03fdb Merge branch 'jk/http-backend-deadlock-2.2' into jk/http-backend-deadlock-2.3
* jk/http-backend-deadlock-2.2:
  http-backend: spool ref negotiation requests to buffer
  t5551: factor out tag creation
  http-backend: fix die recursion with custom handler
2015-05-25 20:44:04 -07:00
Jeff King
6bc0cb5176 http-backend: spool ref negotiation requests to buffer
When http-backend spawns "upload-pack" to do ref
negotiation, it streams the http request body to
upload-pack, who then streams the http response back to the
client as it reads. In theory, git can go full-duplex; the
client can consume our response while it is still sending
the request.  In practice, however, HTTP is a half-duplex
protocol. Even if our client is ready to read and write
simultaneously, we may have other HTTP infrastructure in the
way, including the webserver that spawns our CGI, or any
intermediate proxies.

In at least one documented case[1], this leads to deadlock
when trying a fetch over http. What happens is basically:

  1. Apache proxies the request to the CGI, http-backend.

  2. http-backend gzip-inflates the data and sends
     the result to upload-pack.

  3. upload-pack acts on the data and generates output over
     the pipe back to Apache. Apache isn't reading because
     it's busy writing (step 1).

This works fine most of the time, because the upload-pack
output ends up in a system pipe buffer, and Apache reads
it as soon as it finishes writing. But if both the request
and the response exceed the system pipe buffer size, then we
deadlock (Apache blocks writing to http-backend,
http-backend blocks writing to upload-pack, and upload-pack
blocks writing to Apache).

We need to break the deadlock by spooling either the input
or the output. In this case, it's ideal to spool the input,
because Apache does not start reading either stdout _or_
stderr until we have consumed all of the input. So until we
do so, we cannot even get an error message out to the
client.

The solution is fairly straight-forward: we read the request
body into an in-memory buffer in http-backend, freeing up
Apache, and then feed the data ourselves to upload-pack. But
there are a few important things to note:

  1. We limit the in-memory buffer to prevent an obvious
     denial-of-service attack. This is a new hard limit on
     requests, but it's unlikely to come into play. The
     default value is 10MB, which covers even the ridiculous
     100,000-ref negotation in the included test (that
     actually caps out just over 5MB). But it's configurable
     on the off chance that you don't mind spending some
     extra memory to make even ridiculous requests work.

  2. We must take care only to buffer when we have to. For
     pushes, the incoming packfile may be of arbitrary
     size, and we should connect the input directly to
     receive-pack. There's no deadlock problem here, though,
     because we do not produce any output until the whole
     packfile has been read.

     For upload-pack's initial ref advertisement, we
     similarly do not need to buffer. Even though we may
     generate a lot of output, there is no request body at
     all (i.e., it is a GET, not a POST).

[1] http://article.gmane.org/gmane.comp.version-control.git/269020

Test-adapted-from: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-25 20:43:18 -07:00
Junio C Hamano
ce6ab232ca Merge branch 'sb/t1020-cleanup'
There was a commented-out (instead of being marked to expect
failure) test that documented a breakage that was fixed since the
test was written; turn it into a proper test.

* sb/t1020-cleanup:
  subdirectory tests: code cleanup, uncomment test
2015-05-22 12:42:00 -07:00
Junio C Hamano
ddaf4e2e9a Merge branch 'jc/ignore-epipe-in-filter'
Filter scripts were run with SIGPIPE disabled on the Git side,
expecting that they may not read what Git feeds them to filter.
We however treated a filter that does not read its input fully
before exiting as an error.

This changes semantics, but arguably in a good way.  If a filter
can produce its output without consuming its input using whatever
magic, we now let it do so, instead of diagnosing it as a
programming error.

* jc/ignore-epipe-in-filter:
  filter_buffer_or_fd(): ignore EPIPE
  copy.c: make copy_fd() report its status silently
2015-05-22 12:41:57 -07:00
Junio C Hamano
fb257bfa17 Merge branch 'mh/lockfile-retry'
Instead of dying immediately upon failing to obtain a lock, retry
after a short while with backoff.

* mh/lockfile-retry:
  lock_packed_refs(): allow retries when acquiring the packed-refs lock
  lockfile: allow file locking to be retried with a timeout
2015-05-22 12:41:55 -07:00
Junio C Hamano
29b2041c2a Merge branch 'jk/add-e-kill-editor'
"git add -e" did not allow the user to abort the operation by
killing the editor.

* jk/add-e-kill-editor:
  add: check return value of launch_editor
2015-05-22 12:41:55 -07:00
Junio C Hamano
935d937644 Merge branch 'sg/completion-config'
Code clean-up for completion script (in contrib/).

* sg/completion-config:
  completion: simplify query for config variables
  completion: add a helper function to get config variables
2015-05-22 12:41:54 -07:00
Junio C Hamano
faa4b2ecbb Merge branch 'mh/ref-directory-file'
The ref API did not handle cases where 'refs/heads/xyzzy/frotz' is
removed at the same time as 'refs/heads/xyzzy' is added (or vice
versa) very well.

* mh/ref-directory-file:
  reflog_expire(): integrate lock_ref_sha1_basic() errors into ours
  ref_transaction_commit(): delete extra "the" from error message
  ref_transaction_commit(): provide better error messages
  rename_ref(): integrate lock_ref_sha1_basic() errors into ours
  lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts
  lock_ref_sha1_basic(): report errors via a "struct strbuf *err"
  verify_refname_available(): report errors via a "struct strbuf *err"
  verify_refname_available(): rename function
  refs: check for D/F conflicts among refs created in a transaction
  ref_transaction_commit(): use a string_list for detecting duplicates
  is_refname_available(): use dirname in first loop
  struct nonmatching_ref_data: store a refname instead of a ref_entry
  report_refname_conflict(): inline function
  entry_matches(): inline function
  is_refname_available(): convert local variable "dirname" to strbuf
  is_refname_available(): avoid shadowing "dir" variable
  is_refname_available(): revamp the comments
  t1404: new tests of ref D/F conflicts within transactions
2015-05-22 12:41:53 -07:00
Junio C Hamano
91c90876de Merge branch 'mh/write-refs-sooner-2.4'
Multi-ref transaction support we merged a few releases ago
unnecessarily kept many file descriptors open, risking to fail with
resource exhaustion.  This is for 2.4.x track.

* mh/write-refs-sooner-2.4:
  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 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
2015-05-22 12:41:52 -07:00
Junio C Hamano
fd707807f0 Merge branch 'mg/log-decorate-HEAD'
The "log --decorate" enhancement in Git 2.4 that shows the commit
at the tip of the current branch e.g. "HEAD -> master", did not
work with --decorate=full.

* mg/log-decorate-HEAD:
  log: do not shorten decoration names too early
  log: decorate HEAD with branch name under --decorate=full, too
2015-05-22 12:41:51 -07:00
Junio C Hamano
8087a62086 Merge branch 'jk/skip-http-tests-under-no-curl'
Test clean-up.

* jk/skip-http-tests-under-no-curl:
  tests: skip dav http-push tests under NO_EXPAT=NoThanks
  t/lib-httpd.sh: skip tests if NO_CURL is defined
2015-05-22 12:41:44 -07:00
Jeff King
d6cc2df5c8 stash: complain about unknown flags
The option parser for git-stash stuffs unknown flags into
the $FLAGS variable, where they can be accessed by the
individual commands. However, most commands do not even look
at these extra flags, leading to unexpected results like
this:

  $ git stash drop --help
  Dropped refs/stash@{0} (e6cf6d80faf92bb7828f7b60c47fc61c03bd30a1)

We should notice the extra flags and bail. Rather than
annotate each command to reject a non-empty $FLAGS variable,
we can notice that "stash show" is the only command that
actually _wants_ arbitrary flags. So we switch the default
mode to reject unknown flags, and let stash_show() opt into
the feature.

Reported-by: Vincent Legoll <vincent.legoll@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 13:47:30 -07:00
David Turner
122d53464b cat-file: add --follow-symlinks to --batch
This wires the in-repo-symlink following code through to the cat-file
builtin.  In the event of an out-of-repo link, cat-file will print
the link in a new format.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 13:46:21 -07:00
Jeff King
cc969c8dc1 t5551: factor out tag creation
One of our tests in t5551 creates a large number of tags,
and jumps through some hoops to do it efficiently. Let's
factor that out into a function so we can make other similar
tests.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 10:38:31 -07:00
Junio C Hamano
0c4dd67a04 filter_buffer_or_fd(): ignore EPIPE
We are explicitly ignoring SIGPIPE, as we fully expect that the
filter program may not read our output fully.  Ignore EPIPE that
may come from writing to it as well.

A new test was stolen from Jeff's suggestion.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 10:19:12 -07:00
Junio C Hamano
3b7d373ae2 Merge branch 'kn/cat-file-literally'
Add the "--allow-unknown-type" option to "cat-file" to allow
inspecting loose objects of an experimental or a broken type.

* kn/cat-file-literally:
  t1006: add tests for git cat-file --allow-unknown-type
  cat-file: teach cat-file a '--allow-unknown-type' option
  cat-file: make the options mutually exclusive
  sha1_file: support reading from a loose object of unknown type
2015-05-19 13:17:58 -07:00
Junio C Hamano
bcd1ecd08a Merge branch 'jc/merge'
"git merge FETCH_HEAD" learned that the previous "git fetch" could
be to create an Octopus merge, i.e. recording multiple branches
that are not marked as "not-for-merge"; this allows us to lose an
old style invocation "git merge <msg> HEAD $commits..." in the
implementation of "git pull" script; the old style syntax can now
be deprecated.

* jc/merge:
  merge: deprecate 'git merge <message> HEAD <commit>' syntax
  merge: handle FETCH_HEAD internally
  merge: decide if we auto-generate the message early in collect_parents()
  merge: make collect_parents() auto-generate the merge message
  merge: extract prepare_merge_message() logic out
  merge: narrow scope of merge_names
  merge: split reduce_parents() out of collect_parents()
  merge: clarify collect_parents() logic
  merge: small leakfix and code simplification
  merge: do not check argc to determine number of remote heads
  merge: clarify "pulling into void" special case
  t5520: test pulling an octopus into an unborn branch
  t5520: style fixes
  merge: simplify code flow
  merge: test the top-level merge driver
2015-05-19 13:17:57 -07:00
Junio C Hamano
eae0216646 Merge branch 'ph/rebase-i-redo'
"git rebase -i" moved the "current" command from "todo" to "done" a
bit too prematurely, losing a step when a "pick" did not even start.

* ph/rebase-i-redo:
  rebase -i: redo tasks that die during cherry-pick
2015-05-19 13:17:56 -07:00
Junio C Hamano
072f391c53 Merge branch 'jc/test-prereq-validate'
Help us to find broken test script that splits the body part of the
test by mistaken use of wrong kind of quotes.

* jc/test-prereq-validate:
  test: validate prerequistes syntax
2015-05-19 13:17:55 -07:00
Junio C Hamano
7a4f891329 Merge branch 'bc/connect-plink'
The connection initiation code for "ssh" transport tried to absorb
differences between the stock "ssh" and Putty-supplied "plink" and
its derivatives, but the logic to tell that we are using "plink"
variants were too loose and falsely triggered when "plink" appeared
anywhere in the path (e.g. "/home/me/bin/uplink/ssh").

* bc/connect-plink:
  connect: improve check for plink to reduce false positives
  t5601: fix quotation error leading to skipped tests
  connect: simplify SSH connection code path
2015-05-19 13:17:55 -07:00
Junio C Hamano
da3d507ce0 Merge branch 'jk/test-chain-lint'
Developer support to automatically detect broken &&-chain in the
test scripts is now turned on by default.

* jk/test-chain-lint:
  test-lib: turn on GIT_TEST_CHAIN_LINT by default
  t7502-commit.sh: fix a broken and-chain
2015-05-19 13:17:54 -07:00
Junio C Hamano
05c39674f3 Merge branch 'jk/stash-require-clean-index'
"git stash pop/apply" forgot to make sure that not just the working
tree is clean but also the index is clean. The latter is important
as a stash application can conflict and the index will be used for
conflict resolution.

* jk/stash-require-clean-index:
  stash: require a clean index to apply
  t3903: avoid applying onto dirty index
  t3903: stop hard-coding commit sha1s
2015-05-19 13:17:52 -07:00
Junio C Hamano
20cf8b548e Merge branch 'jc/gitignore-precedence'
core.excludesfile (defaulting to $XDG_HOME/git/ignore) is supposed
to be overridden by repository-specific .git/info/exclude file, but
the order was swapped from the beginning. This belatedly fixes it.

* jc/gitignore-precedence:
  ignore: info/exclude should trump core.excludesfile
2015-05-19 13:17:51 -07:00
Junio C Hamano
d0c692263f Merge branch 'nd/diff-i-t-a'
After "git add -N", the path appeared in output of "git diff HEAD"
and "git diff --cached HEAD", leading "git status" to classify it
as "Changes to be committed".  Such a path, however, is not yet to
be scheduled to be committed.  "git diff" showed the change to the
path as modification, not as a "new file", in the header of its
output.

Treat such paths as "yet to be added to the index but Git already
know about them"; "git diff HEAD" and "git diff --cached HEAD"
should not talk about them, and "git diff" should show them as new
files yet to be added to the index.

* nd/diff-i-t-a:
  diff-lib.c: adjust position of i-t-a entries in diff
2015-05-19 13:17:49 -07:00
Stefan Beller
66d2e04ec9 subdirectory tests: code cleanup, uncomment test
Back when these tests were written, we wanted to make sure that Git
notices it is in a bare repository and "git show -s HEAD" would
refrain from complaining that HEAD might mean a file it sees in its
current working directory (because it does not).  But the version of
Git back then didn't behave well, without (doubly) being told that
it is inside a bare repository by exporting "GIT_DIR=.".  The form
of the test we originally wanted to have was left commented out as
a reminder.

Nowadays the test as originally intended works, so add it to the
test suite.  We'll keep the old test that explicitly sets GIT_DIR=.
to make sure that use case will not regress.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-18 15:22:49 -07:00
Paul Tan
eb8dc05c3d 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>
2015-05-18 11:22:27 -07:00
Paul Tan
5061a44bcc 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>
2015-05-18 11:19:36 -07:00
Jim Hill
f6a1e1e288 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>
2015-05-18 10:15:20 -07:00
Michael Haggerty
f4ab4f3ab1 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>
2015-05-14 14:51:51 -07:00
Junio C Hamano
76c61fbdba 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>
2015-05-13 10:25:18 -07:00
Michael Haggerty
cf018ee0cd 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>
2015-05-12 21:28:03 -07:00
Stefan Beller
fc38a9bb4d 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>
2015-05-12 21:28:02 -07:00
Stefan Beller
d415ad022d 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>
2015-05-12 21:28:02 -07:00
Jeff King
cb64800d83 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>
2015-05-12 20:25:08 -07:00
SZEDER Gábor
12bdc880c7 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>
2015-05-12 15:16:46 -07:00
SZEDER Gábor
e8f9e42829 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>
2015-05-12 15:12:19 -07:00
Junio C Hamano
c99fec6e35 Sync with 2.3.8
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-11 14:39:28 -07:00
Junio C Hamano
811ce1b47c 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>
2015-05-11 14:34:01 -07:00