The description for 'git rebase --abort' currently says:
Restore the original branch and abort the rebase operation.
The "restore" can be misinterpreted to imply that the original branch
was somehow in a broken state during the rebase operation. It is also
not completely clear what "the original branch" is --- is it the
branch that was checked out before the rebase operation was called or
is the the branch that is being rebased (it is the latter)? Although
both issues are made clear in the DESCRIPTION section, let us also
make the entry in the OPTIONS secion more clear.
Also remove the term "rebasing process" from the usage text, since the
user already knows that the text is about "git rebase".
Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The latter is meant to be an API for internal callers that want to inspect
the resulting diff-queue, while the former is an implementation of "git
diff-index" command. Extract the common logic into a single helper
function and make them thin wrappers around it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 34110cd (Make 'unpack_trees()' have a separate source and
destination index, 2008-03-06), we can run unpack_trees() without munging
the index at all, but do_diff_cache() tried ever so carefully to work
around the old behaviour of the function.
We can just tell unpack_trees() not to touch the original index and there
is no need to clean-up whatever the previous round has done.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Because "diff --cached HEAD" showed an incorrect blob object name on the
LHS of the diff, we ended up updating the index entry with bogus value,
not what we read from the tree.
Noticed by John Nowak.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* bc/submodule-foreach-stdin-fix-1.7.4:
git-submodule.sh: preserve stdin for the command spawned by foreach
t/t7407: demonstrate that the command called by 'submodule foreach' loses stdin
Conflicts:
git-submodule.sh
* nk/ref-doc:
glossary: clarify description of HEAD
glossary: update description of head and ref
glossary: update description of "tag"
git.txt: de-emphasize the implementation detail of a ref
check-ref-format doc: de-emphasize the implementation detail of a ref
git-remote.txt: avoid sounding as if loose refs are the only ones in the world
git-remote.txt: fix wrong remote refspec
* rj/config-cygwin:
config.c: Make git_config() work correctly when called recursively
t1301-*.sh: Fix the 'forced modes' test on cygwin
help.c: Fix detection of custom merge strategy on cygwin
* fg/submodule-keep-updating:
git-submodule.sh: clarify the "should we die now" logic
submodule update: continue when a checkout fails
git-sh-setup: add die_with_status
Conflicts:
git-submodule.sh
* an/shallow-doc:
Document the underlying protocol used by shallow repositories and --depth commands.
Fix documentation of fetch-pack that implies that the client can disconnect after sending wants.
For histogram diff, we can afford a smaller sample size and thus a
poorer estimate of the number of lines, as the hash table (rhash) won't
be filled up/grown. This is safe as the final count of lines (xdf.nrecs)
will be updated correctly anyway by xdl_prepare_ctx().
This gives us a small boost in performance.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
xdiff performs "classification" of records (xdl_classify_record()),
replacing hashes (xrecord_t.ha) with a unique identifier of the
record/line and building a hash table (xrecord_t.rhash) of records. This
is then used to "cleanup" records (xdl_cleanup_records()).
We don't need any of that in histogram diff, so we omit calls to these
functions. We also skip allocating memory to the hash table, rhash, as
it is no longer used.
This gives us a small boost in performance.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Port JGit's HistogramDiff algorithm over to C. Rough numbers (TODO) show
that it is faster than its --patience cousin, as well as the default
Meyers algorithm.
The implementation has been reworked to use structs and pointers,
instead of bitmasks, thus doing away with JGit's 2^28 line limit.
We also use xdiff's default hash table implementation (xdl_hash_bits()
with XDL_HASHLONG()) for convenience.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation for logging updates in git-update-ref, doesn't make it
clear that only a specific subset of refs are honored by this variable.
Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
10c4c88 (Allow add_path() to add non-existent directories to the path,
2008-07-21) introduced get_pwd_cwd() function in order to favor $PWD when
getenv("PWD") and getcwd() refer to the same directory but are different
strings (e.g. the former gives a nicer looking name via a symbolic link to
an uglier looking automounted path). The function tried to determine if
two directories are the same by running stat(2) on both and comparing
ino/dev fields.
Unfortunately, stat() does not fill any ino or dev fields in msysgit. But
there is a telltale: both ino and dev are 0 when they are not filled
correctly, so let's be extra cautious.
This happens to fix a bug in "get-receive-pack working_directory/" when
the GIT_DIR would not be set correctly due to absolute_path(".")
returning the wrong value.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Document the namespace mechanism in a new gitnamespaces(7) page.
Reference it from receive-pack and upload-pack.
Document the new --namespace option and GIT_NAMESPACE environment
variable in git(1), and reference gitnamespaces(7).
Add a sample Apache configuration to http-backend(1) to support
namespaced repositories, and reference gitnamespaces(7).
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change upload-pack and receive-pack to use the namespace-prefixed refs
when working with the repository, and use the unprefixed refs when
talking to the client, maintaining the masquerade. This allows
clone, pull, fetch, and push to work with a suitably configured
GIT_NAMESPACE.
receive-pack advertises refs outside the current namespace as .have refs
(as it currently does for refs in alternates), so that the client can
use them to minimize data transfer but will otherwise ignore them.
With appropriate configuration, this also allows http-backend to expose
namespaces as multiple repositories with different paths. This only
requires setting GIT_NAMESPACE, which http-backend passes through to
upload-pack and receive-pack.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This optimizes the "recency order" (see pack-heuristics.txt in
Documentation/technical/ directory) used to order objects within a
packfile in three ways:
- Commits at the tip of tags are written together, in the hope that
revision traversal done in incremental fetch (which starts by
putting them in a revision queue marked as UNINTERESTING) will see a
better locality of these objects;
- In the original recency order, trees and blobs are intermixed. Write
trees together before blobs, in the hope that this will improve
locality when running pathspec-limited revision traversal, i.e.
"git log paths...";
- When writing blob objects out, write the whole family of blobs that use
the same delta base object together, by starting from the root of the
delta chain, and writing its immediate children in a width-first
manner, in the hope that this will again improve locality when reading
blobs that belong to the same path, which are likely to be deltified
against each other.
I tried various workloads in the Linux kernel repositories (HEAD at
v3.0-rc6-71-g4dd1b49) packed with v1.7.6 and with this patch, counting how
large seeks are needed between adjacent accesses to objects in the pack,
and the result looks promising. The history has 2072052 objects, weighing
some 490MiB.
* Simple commit-only log.
$ git log >/dev/null
There are 254656 commits in total.
v1.7.6 with patch
Total number of access : 258,031 258,032
0.0% percentile : 12 12
10.0% percentile : 259 259
20.0% percentile : 294 294
30.0% percentile : 326 326
40.0% percentile : 363 363
50.0% percentile : 415 415
60.0% percentile : 513 513
70.0% percentile : 857 858
80.0% percentile : 10,434 10,441
90.0% percentile : 91,985 91,996
95.0% percentile : 260,852 260,885
99.0% percentile : 1,150,680 1,152,811
99.9% percentile : 3,148,435 3,148,435
Less than 2MiB seek: 99.70% 99.69%
95% of the pack accesses look at data that is no further than 260kB
from the previous location we accessed. The patch does not change the
order of commit objects very much, and the result is very similar.
* Pathspec-limited log.
$ git log drivers/net >/dev/null
The path is touched by 26551 commits and merges (among 254656 total).
v1.7.6 with patch
Total number of access : 559,511 558,663
0.0% percentile : 0 0
10.0% percentile : 182 167
20.0% percentile : 259 233
30.0% percentile : 357 304
40.0% percentile : 714 485
50.0% percentile : 5,046 3,976
60.0% percentile : 688,671 443,578
70.0% percentile : 319,574,732 110,370,100
80.0% percentile : 361,647,599 123,707,229
90.0% percentile : 393,195,669 128,947,636
95.0% percentile : 405,496,875 131,609,321
99.0% percentile : 412,942,470 133,078,115
99.5% percentile : 413,172,266 133,163,349
99.9% percentile : 413,354,356 133,240,445
Less than 2MiB seek: 61.71% 62.87%
With the current pack heuristics, more than 30% of accesses have to
seek further than 300MB; the updated pack heuristics ensures that less
than 0.1% of accesses have to seek further than 135MB. This is largely
due to the fact that the updated heuristics does not mix blobs and
trees together.
* Blame.
$ git blame drivers/net/ne.c >/dev/null
The path is touched by 34 commits and merges.
v1.7.6 with patch
Total number of access : 178,147 178,166
0.0% percentile : 0 0
10.0% percentile : 142 139
20.0% percentile : 222 194
30.0% percentile : 373 300
40.0% percentile : 1,168 837
50.0% percentile : 11,248 7,334
60.0% percentile : 305,121,284 106,850,130
70.0% percentile : 361,427,854 123,709,715
80.0% percentile : 388,127,343 128,171,047
90.0% percentile : 399,987,762 130,200,707
95.0% percentile : 408,230,673 132,174,308
99.0% percentile : 412,947,017 133,181,160
99.5% percentile : 413,312,798 133,220,425
99.9% percentile : 413,352,366 133,269,051
Less than 2MiB seek: 56.47% 56.83%
The result is very similar to the pathspec-limited log above, which
only looks at the tree objects.
* Packing recent history.
$ (git for-each-ref --format='^%(refname)' refs/tags; echo HEAD) |
git pack-objects --revs --stdout >/dev/null
This should pack data worth 71 commits.
v1.7.6 with patch
Total number of access : 11,511 11,514
0.0% percentile : 0 0
10.0% percentile : 48 47
20.0% percentile : 134 98
30.0% percentile : 332 178
40.0% percentile : 1,386 293
50.0% percentile : 8,030 478
60.0% percentile : 33,676 1,195
70.0% percentile : 147,268 26,216
80.0% percentile : 9,178,662 464,598
90.0% percentile : 67,922,665 965,782
95.0% percentile : 87,773,251 1,226,102
99.0% percentile : 98,011,763 1,932,377
99.5% percentile : 100,074,427 33,642,128
99.9% percentile : 105,336,398 275,772,650
Less than 2MiB seek: 77.09% 99.04%
The long-tail part of the result looks worse with the patch, but
the change helps majority of the access. 99.04% of the accesses
need less than 2MiB of seeking, compared to 77.09% with the current
packing heuristics.
* Index pack.
$ git index-pack -v .git/objects/pack/pack*.pack
v1.7.6 with patch
Total number of access : 2,791,228 2,788,802
0.0% percentile : 9 9
10.0% percentile : 140 89
20.0% percentile : 233 167
30.0% percentile : 322 235
40.0% percentile : 464 310
50.0% percentile : 862 423
60.0% percentile : 2,566 686
70.0% percentile : 25,827 1,498
80.0% percentile : 1,317,862 4,971
90.0% percentile : 11,926,385 119,398
95.0% percentile : 41,304,149 952,519
99.0% percentile : 227,613,070 6,709,650
99.5% percentile : 321,265,121 11,734,871
99.9% percentile : 382,919,785 33,155,191
Less than 2MiB seek: 81.73% 96.92%
As the index-pack command already walks objects in the delta chain
order, writing the blobs out in the delta chain order seems to
drastically improve the locality of access.
Note that a half-a-gigabyte packfile comfortably fits in the buffer cache,
and you would unlikely to see much performance difference on a modern and
reasonably beefy machine with enough memory and local disks. Benchmarking
with cold cache (or over NFS) would be interesting.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When executing an external shell script like `git foo` with a bad
shebang, e.g. "#!/usr/bin/not/existing", execvp returns 127 (ENOENT).
Since help_unknown_cmd proposes the use of all external commands similar
to the name of the "unknown" command, it suggests the just failed command
again. Stop it and give some advice to the user.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Group the test cases into two functions, test_diff_(frobnitz|unique).
This in preparation for the histogram diff algorithm, which would also
re-use these test cases.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is in preparation for the histogram diff algorithm, which will also
re-use much of the code to call the default Meyers diff algorithm.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Group free()'s that are called when a malloc() fails in
xdl_prepare_ctx(), making for more readable code.
Also add a free() on ha, in case future git hackers add allocs after the
ha malloc.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use memset() instead of a for loop to initialize. This could give a
performance advantage.
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a workload other than "git log" (without pathspec nor any option that
causes us to inspect trees and blobs), the recency pack order is said to
cause the access jump around quite a bit. Add a hook to allow us observe
how bad it is.
"git config core.logpackaccess /var/tmp/pal.txt" will give you the log
in the specified file.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* commit 'v1.7.6': (3211 commits)
Git 1.7.6
completion: replace core.abbrevguard to core.abbrev
Git 1.7.6-rc3
Documentation: git diff --check respects core.whitespace
gitweb: 'pickaxe' and 'grep' features requires 'search' to be enabled
t7810: avoid unportable use of "echo"
plug a few coverity-spotted leaks
builtin/gc.c: add missing newline in message
tests: link shell libraries into valgrind directory
t/Makefile: pass test opts to valgrind target properly
sh-i18n--envsubst.c: do not #include getopt.h
Fix typo: existant->existent
Git 1.7.6-rc2
gitweb: do not misparse nonnumeric content tag files that contain a digit
Git 1.7.6-rc1
fetch: do not leak a refspec
t3703: skip more tests using colons in file names on Windows
gitweb: Fix usability of $prevent_xss
gitweb: Move "Requirements" up in gitweb/INSTALL
gitweb: Describe CSSMIN and JSMIN in gitweb/INSTALL
...
* commit 'v1.7.0': (4188 commits)
Git 1.7.0
Fix typo in 1.6.6.2 release notes
Re-fix check-ref-format documentation mark-up
archive documentation: attributes are taken from the tree by default
Documentation: minor fixes to RelNotes-1.7.0
bash: support 'git am's new '--continue' option
filter-branch: Fix error message for --prune-empty --commit-filter
am: switch --resolved to --continue
Update draft release notes to 1.7.0 one more time
Git 1.6.6.2
t8003: check exit code of command and error message separately
check-ref-format documentation: fix enumeration mark-up
Documentation: quote braces in {upstream} notation
t3902: Protect against OS X normalization
blame: prevent a segv when -L given start > EOF
git-push: document all the status flags used in the output
Fix parsing of imap.preformattedHTML and imap.sslverify
git-add documentation: Fix shell quoting example
Revert "pack-objects: fix pack generation when using pack_size_limit"
archive: simplify archive format guessing
...
* commit 'v1.6.0': (2063 commits)
GIT 1.6.0
git-p4: chdir now properly sets PWD environment variable in msysGit
Improve error output of git-rebase
t9300: replace '!' with test_must_fail
Git.pm: Make File::Spec and File::Temp requirement lazy
Documentation: document the pager.* configuration setting
git-stash: improve synopsis in help and manual page
Makefile: building git in cygwin 1.7.0
git-am: ignore --binary option
bash-completion: Add non-command git help files to bash-completion
Fix t3700 on filesystems which do not support question marks in names
Utilise our new p4_read_pipe and p4_write_pipe wrappers
Add p4 read_pipe and write_pipe wrappers
bash completion: Add '--merge' long option for 'git log'
bash completion: Add completion for 'git mergetool'
git format-patch documentation: clarify what --cover-letter does
bash completion: 'git apply' should use 'fix' not 'strip'
t5304-prune: adjust file mtime based on system time rather than file mtime
test-parse-options: use appropriate cast in length_callback
Fix escaping of glob special characters in pathspecs
...
Conflicts:
builtin-checkout.c
As resolve_ref() returns a static buffer that is local to the function,
the caller needs to be sure that it will not have any other calls to the
function before it uses the returned value, or store it away with a
strdup(). The code used old.path to record which branch it used to be on,
so that it can say between which branches the switch took place in the
reflog, but sometimes it failed to do so.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The SYNOPSIS sections of most commands that span several lines already
use [verse] to retain line breaks. Most commands that don't span
several lines seem not to use [verse]. In the HTML output, [verse]
does not only preserve line breaks, but also makes the section
indented, which causes a slight inconsistency between commands that
use [verse] and those that don't. Use [verse] in all SYNOPSIS sections
for consistency.
Also remove the blank lines from git-fetch.txt and git-rebase.txt to
align with the other man pages. In the case of git-rebase.txt, which
already uses [verse], the blank line makes the [verse] not apply to
the last line, so removing the blank line also makes the formatting
within the document more consistent.
While at it, add single quotes to 'git cvsimport' for consistency with
other commands.
Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add support for dividing the refs of a single repository into multiple
namespaces, each of which can have its own branches, tags, and HEAD.
Git can expose each namespace as an independent repository to pull from
and push to, while sharing the object store, and exposing all the refs
to operations such as git-gc.
Storing multiple repositories as namespaces of a single repository
avoids storing duplicate copies of the same objects, such as when
storing multiple branches of the same source. The alternates mechanism
provides similar support for avoiding duplicates, but alternates do not
prevent duplication between new objects added to the repositories
without ongoing maintenance, while namespaces do.
To specify a namespace, set the GIT_NAMESPACE environment variable to
the namespace. For each ref namespace, git stores the corresponding
refs in a directory under refs/namespaces/. For example,
GIT_NAMESPACE=foo will store refs under refs/namespaces/foo/. You can
also specify namespaces via the --namespace option to git.
Note that namespaces which include a / will expand to a hierarchy of
namespaces; for example, GIT_NAMESPACE=foo/bar will store refs under
refs/namespaces/foo/refs/namespaces/bar/. This makes paths in
GIT_NAMESPACE behave hierarchically, so that cloning with
GIT_NAMESPACE=foo/bar produces the same result as cloning with
GIT_NAMESPACE=foo and cloning from that repo with GIT_NAMESPACE=bar. It
also avoids ambiguity with strange namespace paths such as
foo/refs/heads/, which could otherwise generate directory/file conflicts
within the refs directory.
Add the infrastructure for ref namespaces: handle the GIT_NAMESPACE
environment variable and --namespace option, and support iterating over
refs in a namespace.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The do_for_each_ref iteration function accepts a prefix and a trim, and
checks for the prefix on each ref before passing in that ref; it also
supports trimming off part of the ref before passing it. However,
do_for_each_ref used trim as the length of the prefix to check, ignoring
the actual length of the prefix. Switch to using prefixcmp, checking
the entire length of the prefix string, to properly support a trim value
different than the length of the prefix.
Several callers passed a prefix of "refs/" to filter out everything
outside of refs/, but a trim of 0 to avoid trimming off the "refs/"; the
trim of 0 meant that the filter of "refs/" no longer applied. Change
these callers to pass an empty prefix instead, to avoid changing the
existing behavior. Various callers count on this lack of filtering,
such as receive-pack which uses add_extra_ref to add alternates as refs
named ".have"; adding filtering would break that, causing
t5501-fetch-push-alternates.sh to fail. That lack of filtering doesn't
currently have any other effect, since the loose ref functions can never
supply refs outside of "refs/", and packed-refs will not normally
include such refs unless manually edited.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This has been there since textconv existed, but was never
documented. There is some overlap with what's in
gitattributes(5), but it's important to warn in both places
that textconv diffs probably can't be applied.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The process may not even have the standard input open in which case it
will get stuck in an infinite loop to prompt and read nothing.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the value from 'core.abbrev' configuration variable unless user
specifies the length on command line when showing commit object name
in "branch -v" output.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
> As you probably guessed from the specificity of the number, I wrote a
> short program to actually traverse and find the worst skew. It takes
> about 5 seconds to run (unsurprisingly, since it is doing the same full
> traversal that we end up doing in the above numbers). So we could
> "autoskew" by setting up the configuration on clone, and then
> periodically updating it as part of "git gc".
This patch doesn't implement auto-detection of skew, but is the program
I used to calculate, and would provide the basis for such
auto-detection. It would be interesting to see average skew numbers for
popular repositories. You can run it as "git skew --all".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enhance usability of 'blob_plain' view protection against XSS attacks
(enabled by setting $prevent_xss to true) by serving contents inline
as safe 'text/plain' mimetype where possible, instead of serving with
"Content-Disposition: attachment" to make sure they don't run in
gitweb's security domain.
This patch broadens downgrading to 'text/plain' further, to any
*/*+xml mimetype. This includes:
application/xhtml+xml (*.xhtml, *.xht)
application/atom+xml (*.atom)
application/rss+xml (*.rss)
application/mathml+xm (*.mathml)
application/docbook+xml (*.docbook)
image/svg+xml (*.svg, *.svgz)
Probably most useful is serving XHTML files as text/plain in
'blob_plain' view, directly viewable.
Because file with 'image/svg+xml' mimetype can be compressed SVGZ
file, we have to check if */*+xml really is text file, via '-T $fd'.
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of mechanism enabled by setting $prevent_xss to true is 'blob_plain'
view protection. With XSS prevention on, blobs of all types except a
few known safe ones are served with "Content-Disposition: attachment" to
make sure they don't run in our security domain.
Instead of serving text/* type files, except text/plain (and including
text/html), as attachements, downgrade it to text/plain. This way HTML
pages in 'blob_plain' (raw) view would be displayed in browser, but
safely as a source, and not asked to be saved.
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The user-supplied command spawned by 'submodule foreach' loses its
connection to the original standard input. Instead, it is connected to the
output of a pipe within the git-submodule script. The user-supplied
command supplied to 'submodule foreach' is spawned within a while loop
which is being piped into. Due to the way shells implement piping output
to a while loop, a subshell is created with its standard input attached to
the output of the pipe. This results in all of the commands executed
within the while loop to have their stdins modified in the same way,
including the user-supplied command.
This can cause a problem if the command requires reading from stdin or if
it changes its behavior based on whether stdin is a tty or not. For
example, this problem was noticed when trying to execute the following:
git submodule foreach git shortlog --since=two.weeks.ago
which printed a message about entering the first submodule and produced no
further output and exited with a status of zero. In this case, shortlog
detected that it was not connected to a tty, and since no revision was
supplied as an argument, it attempted to read the list of revisions from
standard input. Instead, it slurped up the list of submodules that was
being piped to the enclosing while loop and caused that loop to end early
without processing the remaining submodules.
Work around this behavior by saving the original standard input file
descriptor before the while loop, and restoring it when spawning the
user-supplied command.
This fixes the tests in t7407.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The user-supplied command spawned by 'submodule foreach' loses its
connection to the original standard input. Instead, it is connected to the
output of a pipe within the git-submodule script. This can cause a problem
if the command requires reading from stdin or if it changes its behavior
based on whether stdin is a tty or not (e.g. git shortlog). Demonstrate
this flaw.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
