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
"git clean pathspec..." tried to lstat(2) and complain even for
paths outside the given pathspec.
* dt/clean-pathspec-filter-then-lstat:
clean: only lstat files in pathspec
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>
"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
"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
The completion for "log --decorate=" parameter value was incorrect.
* sg/complete-decorate-full-not-long:
completion: fix and update 'git log --decorate=' options
"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
"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
"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
We have prepended $GIT_EXEC_PATH and the path "git" is installed in
(typically "/usr/bin") to $PATH when invoking subprograms and hooks
for almost eternity, but the original use case the latter tried to
support was semi-bogus (i.e. install git to /opt/foo/git and run it
without having /opt/foo on $PATH), and more importantly it has
become less and less relevant as Git grew more mainstream (i.e. the
users would _want_ to have it on their $PATH). Stop prepending the
path in which "git" is installed to users' $PATH, as that would
interfere the command search order people depend on (e.g. they may
not like versions of programs that are unrelated to Git in /usr/bin
and want to override them by having different ones in /usr/local/bin
and have the latter directory earlier in their $PATH).
* jk/git-no-more-argv0-path-munging:
stop putting argv[0] dirname at front of PATH
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()
...
The code to read pack-bitmap wanted to allocate a few hundred
pointers to a structure, but by mistake allocated and leaked memory
enough to hold that many actual structures. Correct the allocation
size and also have it on stack, as it is small enough.
* rs/plug-leak-in-pack-bitmaps:
pack-bitmaps: plug memory leak, fix allocation size for recent_bitmaps
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
"git rerere forget" in a repository without rerere enabled gave a
cryptic error message; it should be a silent no-op instead.
* jk/rerere-forget-check-enabled:
rerere: exit silently on "forget" when rerere is disabled
* 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
* 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
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>
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
The controlling tty-based heuristics to squelch progress output did
not consider that the process may not be talking to a tty at all
(e.g. sending the progress to sideband #2). This is a finishing
touch to a topic that is already in 'master'.
* lm/squelch-bg-progress:
progress: treat "no terminal" as being in the foreground
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
Git 2.4 broke setting verbosity and progress levels on "git clone"
with native transports.
* mh/clone-verbosity-fix:
clone: call transport_set_verbosity before anything else on the newly created transport
There was a dead code that used to handle "git pull --tags" and
show special-cased error message, which was made irrelevant when
the semantics of the option changed back in Git 1.9 days.
* pt/pull-tags-error-diag:
pull: remove --tags error in no merge candidates case
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
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
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
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
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
Various documentation mark-up fixes to make the output more
consistent in general and also make AsciiDoctor (an alternative
formatter) happier.
* jk/asciidoc-markup-fix:
doc: convert AsciiDoc {?foo} to ifdef::foo[]
doc: put example URLs and emails inside literal backticks
doc: drop backslash quoting of some curly braces
doc: convert \--option to --option
doc/add: reformat `--edit` option
doc: fix length of underlined section-title
doc: fix hanging "+"-continuation
doc: fix unquoted use of "{type}"
doc: fix misrendering due to `single quote'
A literal block in the tutorial had lines with unequal lengths to
delimit it from the rest of the document, which choke GitHub's
AsciiDoc renderer.
* jk/stripspace-asciidoctor-fix:
doc: fix unmatched code fences in git-stripspace
A literal block in the tutorial had lines with unequal lengths to
delimit it from the rest of the document, which choke GitHub's
AsciiDoc renderer.
* ja/tutorial-asciidoctor-fix:
doc: fix unmatched code fences
Introduce http.<url>.SSLCipherList configuration variable to tweak
the list of cipher suite to be used with libcURL when talking with
https:// sites.
* ls/http-ssl-cipher-list:
http: add support for specifying an SSL cipher list
"git subtree" script (in contrib/) used "echo -n" to produce
progress messages in a non-portable way.
* dl/subtree-avoid-tricky-echo:
contrib/subtree: portability fix for string printing
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
"git subtree" script (in contrib/) does not have --squash option
when pushing, but the documentation and help text pretended as if
it did.
* dl/subtree-push-no-squash:
contrib/subtree: there's no push --squash
The Git subcommand completion (in contrib/) listed credential
helpers among candidates, which is not something the end user would
invoke interatively.
* sg/completion-omit-credential-helpers:
completion: remove credential helpers from porcelain commands
Error messages from "git branch" called remote-tracking branches as
"remote branches".
* dl/branch-error-message:
branch: do not call a "remote-tracking branch" a "remote branch"
Fix remaining instances where "pack-file" is used instead of
"packfile". Some places remain where we still use "pack-file",
This is the case when we explicitly refer to a file with a
".pack" extension as opposed to a data source providing a pack
data stream.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
