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* pt/t0302-needs-sanity:
t0302: "unreadable" test needs SANITY prereq
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"git format-patch --ignore-if-upstream A..B" did not like to be fed
tags as boundary commits.
* jc/do-not-feed-tags-to-clear-commit-marks:
format-patch: do not feed tags to clear_commit_marks()
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A hotfix for the topic already in 'master'.
* jk/stash-require-clean-index:
Revert "stash: require a clean index to apply"
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The setup code used to die when core.bare and core.worktree are set
inconsistently, even for commands that do not need working tree.
* jk/die-on-bogus-worktree-late:
setup_git_directory: delay core.bare/core.worktree errors
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Recent "git prune" traverses young unreachable objects to safekeep
old objects in the reachability chain from them, which sometimes
caused error messages that are unnecessarily alarming.
* jk/squelch-missing-link-warning-for-unreachable:
suppress errors on missing UNINTERESTING links
silence broken link warnings with revs->ignore_missing_links
add quieter versions of parse_{tree,commit}
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"git rebase -i" fired post-rewrite hook when it shouldn't (namely,
when it was told to stop sequencing with 'exec' insn).
* mm/rebase-i-post-rewrite-exec:
t5407: use <<- to align the expected output
rebase -i: fix post-rewrite hook with failed exec command
rebase -i: demonstrate incorrect behavior of post-rewrite
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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
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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
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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
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This reverts commit ed178ef13a26136d86ff4e33bb7b1afb5033f908.
That commit was an attempt to improve the safety of applying
a stash, because the application process may create
conflicted index entries, after which it is hard to restore
the original index state.
Unfortunately, this hurts some common workflows around "git
stash -k", like:
git add -p ;# (1) stage set of proposed changes
git stash -k ;# (2) get rid of everything else
make test ;# (3) make sure proposal is reasonable
git stash apply ;# (4) restore original working tree
If you "git commit" between steps (3) and (4), then this
just works. However, if these steps are part of a pre-commit
hook, you don't have that opportunity (you have to restore
the original state regardless of whether the tests passed or
failed).
It's possible that we could provide better tools for this
sort of workflow. In particular, even before ed178ef, it
could fail with a conflict if there were conflicting hunks
in the working tree and index (since the "stash -k" puts the
index version into the working tree, and we then attempt to
apply the differences between HEAD and the old working tree
on top of that). But the fact remains that people have been
using it happily for a while, and the safety provided by
ed178ef is simply not that great. Let's revert it for now.
In the long run, people can work on improving stash for this
sort of workflow, but the safety tradeoff is not worth it in
the meantime.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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The test expects that "chmod -r ~/.git-credentials" would make it
unreadable to the user, and thus needs the SANITY prerequisite.
Reported-by: Jean-Yves LENHOF <jean-yves@lenhof.eu.org>
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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
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"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>
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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
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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
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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
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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
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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
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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
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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
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"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
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"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
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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
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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()
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
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"git format-patch --ignore-if-in-upstream A..B", when either A or B
is a tag, failed miserably.
This is because the code passes the tips it used for traversal to
clear_commit_marks(), after running a temporary revision traversal
to enumerate the commits on both branches to find if they have
commits that make equivalent changes. The revision traversal
machinery knows how to enumerate commits reachable starting from a
tag, but clear_commit_marks() wants to take nothing but a commit.
In the longer term, it might be a more correct fix to teach
clear_commit_marks() to do the same "committish to commit"
dereferencing that is done in the revision traversal machinery,
but for now this fix should suffice.
Reported-by: Bruce Korb <bruce.korb@gmail.com>
Helped-by: Christian Couder <christian.couder@gmail.com>
Helped-by: brian m. carlson <sandals@crustytoothpaste.net>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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We set revs->ignore_missing_links to instruct the
revision-walking machinery that we know the history graph
may be incomplete. For example, we use it when walking
unreachable but recent objects; we want to add what we can,
but it's OK if the history is incomplete.
However, we still print error messages for the missing
objects, which can be confusing. This is not an error, but
just a normal situation when transitioning from a repository
last pruned by an older git (which can leave broken segments
of history) to a more recent one (where we try to preserve
whole reachable segments).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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If both core.bare and core.worktree are set, we complain
about the bogus config and die. Dying is good, because it
avoids commands running and doing damage in a potentially
incorrect setup. But dying _there_ is bad, because it means
that commands which do not even care about the work tree
cannot run. This can make repairing the situation harder:
[setup]
$ git config core.bare true
$ git config core.worktree /some/path
[OK, expected.]
$ git status
fatal: core.bare and core.worktree do not make sense
[Hrm...]
$ git config --unset core.worktree
fatal: core.bare and core.worktree do not make sense
[Nope...]
$ git config --edit
fatal: core.bare and core.worktree do not make sense
[Gaaah.]
$ git help config
fatal: core.bare and core.worktree do not make sense
Instead, let's issue a warning about the bogus config when
we notice it (i.e., for all commands), but only die when the
command tries to use the work tree (by calling setup_work_tree).
So we now get:
$ git status
warning: core.bare and core.worktree do not make sense
fatal: unable to set up work tree using invalid config
$ git config --unset core.worktree
warning: core.bare and core.worktree do not make sense
We have to update t1510 to accomodate this; it uses
symbolic-ref to check whether the configuration works or
not, but of course that command does not use the working
tree. Instead, we switch it to use `git status`, as it
requires a work-tree, does not need any special setup, and
is read-only (so a failure will not adversely affect further
tests).
In addition, we add a new test that checks the desired
behavior (i.e., that running "git config" with the bogus
config does in fact work).
Reported-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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"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
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"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
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"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
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* 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
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* 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
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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>
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Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Usually, when 'git rebase' stops before completing the rebase, it is to
give the user an opportunity to edit a commit (e.g. with the 'edit'
command). In such cases, 'git rebase' leaves the sha1 of the commit being
rewritten in "$state_dir"/stopped-sha, and subsequent 'git rebase
--continue' will call the post-rewrite hook with this sha1 as <old-sha1>
argument to the post-rewrite hook.
The case of 'git rebase' stopping because of a failed 'exec' command is
different: it gives the opportunity to the user to examine or fix the
failure, but does not stop saying "here's a commit to edit, use
--continue when you're done". So, there's no reason to call the
post-rewrite hook for 'exec' commands. If the user did rewrite the
commit, it would be with 'git commit --amend' which already called the
post-rewrite hook.
Fix the behavior to leave no stopped-sha file in case of failed exec
command, and teach 'git rebase --continue' to skip record_in_rewritten if
no stopped-sha file is found.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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The 'exec' command is sending the current commit to stopped-sha, which is
supposed to contain the original commit (before rebase). As a result, if
an 'exec' command fails, the next 'git rebase --continue' will send the
current commit as <old-sha1> to the post-rewrite hook.
The test currently fails with :
--- expected.data 2015-05-21 17:55:29.000000000 +0000
+++ [...]post-rewrite.data 2015-05-21 17:55:29.000000000 +0000
@@ -1,2 +1,3 @@
2362ae8e1b1b865e6161e6f0e165ffb974abf018 488028e9fac0b598b70cbeb594258a917e3f6fab
+488028e9fac0b598b70cbeb594258a917e3f6fab 488028e9fac0b598b70cbeb594258a917e3f6fab
babc8a4c7470895886fc129f1a015c486d05a351 8edffcc4e69a4e696a1d4bab047df450caf99507
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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>
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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>
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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>
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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>
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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>
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`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>
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Correct test bitrot.
* nd/t1509-chroot-test:
t1509: update prepare script to be able to run t1509 in chroot again
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"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
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* ep/fix-test-lib-functions-report:
test-lib-functions.sh: fix the second argument to some helper functions
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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
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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>
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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>
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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>
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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>
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Junio C Hamano
Jeff King
Paul Tan
Matthieu Moy
Stefan Beller
Jim Hill
Michael Haggerty