Commit Graph

10935 Commits

Author SHA1 Message Date
Eric Wong
c0071ae5dc git-svn: allow --version to work anywhere
Checking the version of the installed SVN libraries should not
require a git repository at all.  This matches the behavior of
"git --version".

Add a test for "git svn help" for the same behavior while we're
at it, too.

Signed-off-by: Eric Wong <e@80x24.org>
2016-07-22 20:38:11 +00:00
Junio C Hamano
29493589e9 archive-tar: huge offset and future timestamps would not work on 32-bit
As we are not yet moving everything to size_t but still using ulong
internally when talking about the size of object, platforms with
32-bit long will not be able to produce tar archive with 4GB+ file,
and cannot grok 077777777777UL as a constant.  Disable the extended
header feature and do not test it on them.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-15 10:51:55 -07:00
Junio C Hamano
82246e075e Sync with 2.9.2
* maint:
  Git 2.9.2
  t0006: skip "far in the future" test when unsigned long is not long enough
2016-07-15 10:49:23 -07:00
Junio C Hamano
33eacd3ff4 Merge branch 'jk/tzoffset-fix' into maint
Skip tests that are unrunnable on platforms without 64-bit long
to avoid unnecessary test failures.

* jk/tzoffset-fix:
  t0006: skip "far in the future" test when unsigned long is not long enough
2016-07-15 09:43:42 -07:00
Jeff King
6b9c38e14c t0006: skip "far in the future" test when unsigned long is not long enough
Git's source code refers to timestamps as unsigned longs.  On 32-bit
platforms, as well as on Windows, unsigned long is not large enough
to capture dates that are "absurdly far in the future".

While we can fix this issue properly by replacing unsigned long with
a larger type, we want to be a bit more conservative and just skip
those tests on the maint track.

Signed-off-by: Jeff King <peff@peff.net>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-15 09:05:53 -07:00
Junio C Hamano
75676c8c8b Merge branch 'jk/upload-pack-hook'
A hot-fix to make a test working in mingw again.

* jk/upload-pack-hook:
  mingw: fix regression in t1308-config-set
2016-07-14 10:38:57 -07:00
Johannes Schindelin
b738396cfd mingw: fix regression in t1308-config-set
When we tried to fix in 58461bd (t1308: do not get fooled by symbolic
links to the source tree, 2016-06-02) an obscure case where the user
cd's into Git's source code via a symbolic link, a regression was
introduced that affects all test runs on Windows.

The original patch introducing the test case in question was careful to
use `$(pwd)` instead of `$PWD`.

This was done to account for the fact that Git's test suite uses shell
scripting even on Windows, where the shell's Unix-y paths are
incompatible with the main Git executable's idea of paths: it only
accepts Windows paths.

It is an awkward but necessary thing, then, to use `$(pwd)` (which gives
us a Windows path) when interacting with the Git executable and `$PWD`
(which gives the shell's idea of the current working directory in Unix-y
form) for shell scripts, including the test suite itself.

Obviously this broke the use case of the Git maintainer when changing
the working directory into Git's source code directory via a symlink,
i.e. when `$(pwd)` does not agree with `$PWD`.

However, we must not fix that use case at the expense of regressing
another use case.

Let's special-case Windows here, even if it is ugly, for lack of a more
elegant solution.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-14 10:38:28 -07:00
Junio C Hamano
7a23f7367d Merge branch 'jk/big-and-future-archive-tar'
"git archive" learned to handle files that are larger than 8GB and
commits far in the future than expressible by the traditional US-TAR
format.

* jk/big-and-future-archive-tar:
  archive-tar: drop return value
  archive-tar: write extended headers for far-future mtime
  archive-tar: write extended headers for file sizes >= 8GB
  t5000: test tar files that overflow ustar headers
  t9300: factor out portable "head -c" replacement
2016-07-13 11:24:18 -07:00
Junio C Hamano
42bd66816b Merge branch 'nd/ita-cleanup'
Git does not know what the contents in the index should be for a
path added with "git add -N" yet, so "git grep --cached" should not
show hits (or show lack of hits, with -L) in such a path, but that
logic does not apply to "git grep", i.e. searching in the working
tree files.  But we did so by mistake, which has been corrected.

* nd/ita-cleanup:
  grep: fix grepping for "intent to add" files
  t7810-grep.sh: fix a whitespace inconsistency
  t7810-grep.sh: fix duplicated test name
2016-07-13 11:24:18 -07:00
Junio C Hamano
5eb1e9f1a0 Merge branch 'ps/rebase-i-auto-unstash-upon-abort'
"git rebase -i --autostash" did not restore the auto-stashed change
when the operation was aborted.

* ps/rebase-i-auto-unstash-upon-abort:
  rebase -i: restore autostash on abort
2016-07-13 11:24:17 -07:00
Junio C Hamano
6c35952a08 Merge branch 'js/t3404-grammo-fix'
Grammofix.

* js/t3404-grammo-fix:
  t3404: fix a grammo (commands are ran -> commands are run)
2016-07-13 11:24:16 -07:00
Junio C Hamano
fc8a3a6072 Merge branch 'dg/subtree-rebase-test'
Add a test to specify the desired behaviour that currently is not
available in "git rebase -Xsubtree=...".

* dg/subtree-rebase-test:
  contrib/subtree: Add a test for subtree rebase that loses commits
2016-07-13 11:24:13 -07:00
Junio C Hamano
67166a8da6 Merge branch 'ah/unpack-trees-advice-messages'
Grammofix.

* ah/unpack-trees-advice-messages:
  unpack-trees: fix English grammar in do-this-before-that messages
2016-07-13 11:24:11 -07:00
Junio C Hamano
2703572b3a Merge branch 'va/i18n-even-more'
More markings of messages for i18n, with updates to various tests
to pass GETTEXT_POISON tests.

One patch from the original submission dropped due to conflicts
with jk/upload-pack-hook, which is still in flux.

* va/i18n-even-more: (38 commits)
  t5541: become resilient to GETTEXT_POISON
  i18n: branch: mark comment when editing branch description for translation
  i18n: unmark die messages for translation
  i18n: submodule: escape shell variables inside eval_gettext
  i18n: submodule: join strings marked for translation
  i18n: init-db: join message pieces
  i18n: remote: allow translations to reorder message
  i18n: remote: mark URL fallback text for translation
  i18n: standardise messages
  i18n: sequencer: add period to error message
  i18n: merge: change command option help to lowercase
  i18n: merge: mark messages for translation
  i18n: notes: mark options for translation
  i18n: notes: mark strings for translation
  i18n: transport-helper.c: change N_() call to _()
  i18n: bisect: mark strings for translation
  t5523: use test_i18ngrep for negation
  t4153: fix negated test_i18ngrep call
  t9003: become resilient to GETTEXT_POISON
  tests: unpack-trees: update to use test_i18n* functions
  ...
2016-07-13 11:24:10 -07:00
Junio C Hamano
3a30c14b9b Merge branch 'jc/t2300-setup' into maint
Portability fix for Windows.

* jc/t2300-setup:
  t2300: "git --exec-path" is not usable in $PATH on Windows as-is
2016-07-11 10:44:19 -07:00
Junio C Hamano
438d4e7583 Merge branch 'cb/t7810-test-label-fix' into maint
Test clean-up.

* cb/t7810-test-label-fix:
  t7810: fix duplicated test title
2016-07-11 10:44:18 -07:00
Junio C Hamano
3e69d1b6cd Merge branch 'sb/t5614-modernize' into maint
Test clean-up.

* sb/t5614-modernize:
  t5614: don't use subshells
2016-07-11 10:44:17 -07:00
Junio C Hamano
ce22ea22e8 Merge branch 'js/perf-on-apple' into maint
t/perf needs /usr/bin/time with GNU extension; the invocation of it
is updated to "gtime" on Darwin.

* js/perf-on-apple:
  perf: accommodate for MacOSX
2016-07-11 10:44:15 -07:00
Junio C Hamano
c4cdde45f0 Merge branch 'ak/t7800-wo-readlink' into maint
One among four invocations of readlink(1) in our test suite has
been rewritten so that the test can run on systems without the
command (others are in valgrind test framework and t9802).

* ak/t7800-wo-readlink:
  t7800: readlink may not be available
2016-07-11 10:44:15 -07:00
Junio C Hamano
0c72d6da31 Merge branch 'jk/tzoffset-fix' into maint
The internal code used to show local timezone offset is not
prepared to handle timestamps beyond year 2100, and gave a
bogus offset value to the caller.  Use a more benign looking
+0000 instead and let "git log" going in such a case, instead
of aborting.

* jk/tzoffset-fix:
  local_tzoffset: detect errors from tm_to_time_t
  t0006: test various date formats
  t0006: rename test-date's "show" to "relative"
2016-07-11 10:44:14 -07:00
Junio C Hamano
1a88ca99db Merge branch 'sb/clone-shallow-passthru' into maint
Fix an unintended regression in v2.9 that breaks "clone --depth"
that recurses down to submodules by forcing the submodules to also
be cloned shallowly, which many server instances that host upstream
of the submodules are not prepared for.

* sb/clone-shallow-passthru:
  clone: do not let --depth imply --shallow-submodules
2016-07-11 10:44:12 -07:00
Junio C Hamano
5f30bb4a81 Merge branch 'nd/graph-width-padded' into maint
"log --graph --format=" learned that "%>|(N)" specifies the width
relative to the terminal's left edge, not relative to the area to
draw text that is to the right of the ancestry-graph section.  It
also now accepts negative N that means the column limit is relative
to the right border.

* nd/graph-width-padded:
  pretty.c: support <direction>|(<negative number>) forms
  pretty: pass graph width to pretty formatting for use in '%>|(N)'
2016-07-11 10:44:09 -07:00
Junio C Hamano
369dc4081c Merge branch 'mj/log-show-signature-conf'
"git log" learns log.showSignature configuration variable, and a
command line option "--no-show-signature" to countermand it.

* mj/log-show-signature-conf:
  log: add log.showSignature configuration variable
  log: add "--no-show-signature" command line option
  t4202: refactor test
2016-07-11 10:31:08 -07:00
Junio C Hamano
62e5e83f8d Merge branch 'js/find-commit-subject-ignore-leading-blanks'
A helper function that takes the contents of a commit object and
finds its subject line did not ignore leading blank lines, as is
commonly done by other codepaths.  Make it ignore leading blank
lines to match.

* js/find-commit-subject-ignore-leading-blanks:
  reset --hard: skip blank lines when reporting the commit subject
  sequencer: use skip_blank_lines() to find the commit subject
  commit -C: skip blank lines at the beginning of the message
  commit.c: make find_commit_subject() more robust
  pretty: make the skip_blank_lines() function public
2016-07-11 10:31:08 -07:00
Junio C Hamano
e9a6d71331 Merge branch 'jk/perf-any-version'
Allow t/perf framework to use the features from the most recent
version of Git even when testing an older installed version.

* jk/perf-any-version:
  p4211: explicitly disable renames in no-rename test
  t/perf: fix regression in testing older versions of git
2016-07-11 10:31:06 -07:00
Junio C Hamano
3c5de5c77b Merge branch 'jk/ansi-color'
The output coloring scheme learned two new attributes, italic and
strike, in addition to existing bold, reverse, etc.

* jk/ansi-color:
  color: support strike-through attribute
  color: support "italic" attribute
  color: allow "no-" for negating attributes
  color: refactor parse_attr
  add skip_prefix_mem helper
  doc: refactor description of color format
  color: fix max-size comment
2016-07-11 10:31:05 -07:00
Junio C Hamano
afb516e364 Merge branch 'jc/t2300-setup'
Portability fix for Windows.

* jc/t2300-setup:
  t2300: "git --exec-path" is not usable in $PATH on Windows as-is
2016-07-06 13:38:20 -07:00
Junio C Hamano
4cea655a47 Merge branch 'cb/t7810-test-label-fix'
Test clean-up.

* cb/t7810-test-label-fix:
  t7810: fix duplicated test title
2016-07-06 13:38:18 -07:00
Junio C Hamano
8db528cf5a Merge branch 'sb/t5614-modernize'
Test clean-up.

* sb/t5614-modernize:
  t5614: don't use subshells
2016-07-06 13:38:17 -07:00
Junio C Hamano
3437017fec Merge branch 'js/perf-on-apple'
t/perf needs /usr/bin/time with GNU extension; the invocation of it
is updated to "gtime" on Darwin.

* js/perf-on-apple:
  perf: accommodate for MacOSX
2016-07-06 13:38:16 -07:00
Junio C Hamano
3edaee74fd Merge branch 'ak/t7800-wo-readlink'
One among four invocations of readlink(1) in our test suite has
been rewritten so that the test can run on systems without the
command (others are in valgrind test framework and t9802).

* ak/t7800-wo-readlink:
  t7800: readlink may not be available
2016-07-06 13:38:16 -07:00
Junio C Hamano
f6a729f344 Merge branch 'jk/tzoffset-fix'
The internal code used to show local timezone offset is not
prepared to handle timestamps beyond year 2100, and gave a
bogus offset value to the caller.  Use a more benign looking
+0000 instead and let "git log" going in such a case, instead
of aborting.

* jk/tzoffset-fix:
  local_tzoffset: detect errors from tm_to_time_t
  t0006: test various date formats
  t0006: rename test-date's "show" to "relative"
2016-07-06 13:38:15 -07:00
Junio C Hamano
9f1027d18a Merge branch 'sb/clone-shallow-passthru'
Fix an unintended regression in v2.9 that breaks "clone --depth"
that recurses down to submodules by forcing the submodules to also
be cloned shallowly, which many server instances that host upstream
of the submodules are not prepared for.

* sb/clone-shallow-passthru:
  clone: do not let --depth imply --shallow-submodules
2016-07-06 13:38:13 -07:00
Junio C Hamano
ed0f7bdec9 Merge branch 'jk/gpg-interface-cleanup'
A new run-command API function pipe_command() is introduced to
sanely feed data to the standard input while capturing data from
the standard output and the standard error of an external process,
which is cumbersome to hand-roll correctly without deadlocking.

The codepath to sign data in a prepared buffer with GPG has been
updated to use this API to read from the status-fd to check for
errors (instead of relying on GPG's exit status).

* jk/gpg-interface-cleanup:
  gpg-interface: check gpg signature creation status
  sign_buffer: use pipe_command
  verify_signed_buffer: use pipe_command
  run-command: add pipe_command helper
  verify_signed_buffer: use tempfile object
  verify_signed_buffer: drop pbuf variable
  gpg-interface: use child_process.args
2016-07-06 13:38:12 -07:00
Junio C Hamano
f2140c3890 Merge branch 'nd/graph-width-padded'
"log --graph --format=" learned that "%>|(N)" specifies the width
relative to the terminal's left edge, not relative to the area to
draw text that is to the right of the ancestry-graph section.  It
also now accepts negative N that means the column limit is relative
to the right border.

* nd/graph-width-padded:
  pretty.c: support <direction>|(<negative number>) forms
  pretty: pass graph width to pretty formatting for use in '%>|(N)'
2016-07-06 13:38:12 -07:00
Junio C Hamano
979f030359 Merge branch 'jk/repack-keep-unreachable'
"git repack" learned the "--keep-unreachable" option, which sends
loose unreachable objects to a pack instead of leaving them loose.
This helps heuristics based on the number of loose objects
(e.g. "gc --auto").

* jk/repack-keep-unreachable:
  repack: extend --keep-unreachable to loose objects
  repack: add --keep-unreachable option
  repack: document --unpack-unreachable option
2016-07-06 13:38:11 -07:00
Junio C Hamano
e25a4ded8a Merge branch 'ew/mboxrd-format-am'
Teach format-patch and mailsplit (hence "am") how a line that
happens to begin with "From " in the e-mail message is quoted with
">", so that these lines can be restored to their original shape.

* ew/mboxrd-format-am:
  am: support --patch-format=mboxrd
  mailsplit: support unescaping mboxrd messages
  pretty: support "mboxrd" output format
2016-07-06 13:38:11 -07:00
Junio C Hamano
1e4bf90789 Merge branch 'jk/upload-pack-hook'
"upload-pack" allows a custom "git pack-objects" replacement when
responding to "fetch/clone" via the uploadpack.packObjectsHook.

* jk/upload-pack-hook:
  upload-pack: provide a hook for running pack-objects
  t1308: do not get fooled by symbolic links to the source tree
  config: add a notion of "scope"
  config: return configset value for current_config_ functions
  config: set up config_source for command-line config
  git_config_parse_parameter: refactor cleanup code
  git_config_with_options: drop "found" counting
2016-07-06 13:38:11 -07:00
Junio C Hamano
34bf3bbb30 Merge branch 'nd/test-lib-httpd-show-error-log-in-verbose'
HTTPd tests learned to show the server error log to help diagnosing
a failing tests.

* nd/test-lib-httpd-show-error-log-in-verbose:
  lib-httpd.sh: print error.log on error
2016-07-06 13:38:08 -07:00
Junio C Hamano
b8b6365a8a Merge branch 'jk/string-list-static-init'
Instead of taking advantage of a struct string_list that is
allocated with all NULs happens to be STRING_LIST_INIT_NODUP kind,
initialize them explicitly as such, to document their behaviour
better.

* jk/string-list-static-init:
  use string_list initializer consistently
  blame,shortlog: don't make local option variables static
  interpret-trailers: don't duplicate option strings
  parse_opt_string_list: stop allocating new strings
2016-07-06 13:38:08 -07:00
Junio C Hamano
c8b080af71 Merge branch 'et/add-chmod-x' into maint
"git update-index --add --chmod=+x file" may be usable as an escape
hatch, but not a friendly thing to force for people who do need to
use it regularly.  "git add --chmod=+x file" can be used instead.

* et/add-chmod-x:
  add: add --chmod=+x / --chmod=-x options
2016-07-06 13:06:39 -07:00
Junio C Hamano
7949837520 Merge branch 'sg/reflog-past-root' into maint
"git reflog" stopped upon seeing an entry that denotes a branch
creation event (aka "unborn"), which made it appear as if the
reflog was truncated.

* sg/reflog-past-root:
  reflog: continue walking the reflog past root commits
2016-07-06 13:06:37 -07:00
Charles Bailey
b8e47d1acf grep: fix grepping for "intent to add" files
This reverts commit 4d5520053 (grep: make it clear i-t-a entries are
ignored, 2015-12-27) and adds an alternative fix to maintain the -L
--cached behavior.

4d5520053 caused 'git grep' to no longer find matches in new files in
the working tree where the corresponding index entry had the "intent to
add" bit set, despite the fact that these files are tracked.

The content in the index of a file for which the "intent to add" bit is
set is considered indeterminate and not empty. For most grep queries we
want these to behave the same, however for -L --cached (files without a
match) we don't want to respond positively for "intent to add" files as
their contents are indeterminate. This is in contrast to files with
empty contents in the index (no lines implies no matches for any grep
query expression) which should be reported in the output of a grep -L
--cached invocation.

Add tests to cover this case and a few related cases which previously
lacked coverage.

Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Charles Bailey <cbailey32@bloomberg.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 13:27:41 -07:00
Charles Bailey
89e64100f4 t7810-grep.sh: fix a whitespace inconsistency
Signed-off-by: Charles Bailey <charles@hashpling.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 13:27:38 -07:00
Charles Bailey
878452b966 t7810-grep.sh: fix duplicated test name
Signed-off-by: Charles Bailey <charles@hashpling.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 13:26:30 -07:00
Vasco Almeida
415c7dd026 t5541: become resilient to GETTEXT_POISON
Use test_i18n* functions for testing text already marked for
translation.

Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 12:47:30 -07:00
Jeff King
6e8e0991e5 archive-tar: write extended headers for far-future mtime
The ustar format represents timestamps as seconds since the
epoch, but only has room to store 11 octal digits.  To
express anything larger, we need to use an extended header.
This is exactly the same case we fixed for the size field in
the previous commit, and the solution here follows the same
pattern.

This is even mentioned as an issue in f2f0267 (archive-tar:
use xsnprintf for trivial formatting, 2015-09-24), but since
it only affected things far in the future, it wasn't deemed
worth dealing with. But note that my calculations claiming
thousands of years were off there; because our xsnprintf
produces a NUL byte, we only have until the year 2242 to fix
this.

Given that this is just around the corner (geologically
speaking, anyway), and because it's easy to fix, let's just
make it work. Unlike the previous fix for "size", where we
had to write an individual extended header for each file, we
can write one global header (since we have only one mtime
for the whole archive).

There's a slight bit of trickiness there. We may already be
writing a global header with a "comment" field for the
commit sha1. So we need to write our new field into the same
header. To do this, we push the decision of whether to write
such a header down into write_global_extended_header(),
which will now assemble the header as it sees fit, and will
return early if we have nothing to write (in practice, we'll
only have a large mtime if it comes from a commit, but this
makes it also work if you set your system clock ahead such
that time() returns a huge value).

Note that we don't (and never did) handle negative
timestamps (i.e., before 1970). This would probably not be
too hard to support in the same way, but since git does not
support negative timestamps at all, I didn't bother here.

After writing the extended header, we munge the timestamp in
the ustar headers to the maximum-allowable size. This is
wrong, but it's the least-wrong thing we can provide to a
tar implementation that doesn't understand pax headers (it's
also what GNU tar does).

Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 10:26:01 -07:00
Jeff King
d1657b570a archive-tar: write extended headers for file sizes >= 8GB
The ustar format has a fixed-length field for the size of
each file entry which is supposed to contain up to 11 bytes
of octal-formatted data plus a NUL or space terminator.

These means that the largest size we can represent is
077777777777, or 1 byte short of 8GB. The correct solution
for a larger file, according to POSIX.1-2001, is to add an
extended pax header, similar to how we handle long
filenames. This patch does that, and writes zero for the
size field in the ustar header (the last bit is not
mentioned by POSIX, but it matches how GNU tar behaves with
--format=pax).

This should be a strict improvement over the current
behavior, which is to die in xsnprintf with a "BUG".
However, there's some interesting history here.

Prior to f2f0267 (archive-tar: use xsnprintf for trivial
formatting, 2015-09-24), we silently overflowed the "size"
field. The extra bytes ended up in the "mtime" field of the
header, which was then immediately written itself,
overwriting our extra bytes. What that means depends on how
many bytes we wrote.

If the size was 64GB or greater, then we actually overflowed
digits into the mtime field, meaning our value was
effectively right-shifted by those lost octal digits. And
this patch is again a strict improvement over that.

But if the size was between 8GB and 64GB, then our 12-byte
field held all of the actual digits, and only our NUL
terminator overflowed. According to POSIX, there should be a
NUL or space at the end of the field. However, GNU tar seems
to be lenient here, and will correctly parse a size up 64GB
(minus one) from the field. So sizes in this range might
have just worked, depending on the implementation reading
the tarfile.

This patch is mostly still an improvement there, as the 8GB
limit is specifically mentioned in POSIX as the correct
limit. But it's possible that it could be a regression
(versus the pre-f2f0267 state) if all of the following are
true:

  1. You have a file between 8GB and 64GB.

  2. Your tar implementation _doesn't_ know about pax
     extended headers.

  3. Your tar implementation _does_ parse 12-byte sizes from
     the ustar header without a delimiter.

It's probably not worth worrying about such an obscure set
of conditions, but I'm documenting it here just in case.

Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 10:25:46 -07:00
Jeff King
e51217e15c t5000: test tar files that overflow ustar headers
The ustar format only has room for 11 (or 12, depending on
some implementations) octal digits for the size and mtime of
each file. For values larger than this, we have to add pax
extended headers to specify the real data, and git does not
yet know how to do so.

Before fixing that, let's start off with some test
infrastructure, as designing portable and efficient tests
for this is non-trivial.

We want to use the system tar to check our output (because
what we really care about is interoperability), but we can't
rely on it:

  1. being able to read pax headers

  2. being able to handle huge sizes or mtimes

  3. supporting a "t" format we can parse

So as a prerequisite, we can feed the system tar a reference
tarball to make sure it can handle these features. The
reference tar here was created with:

  dd if=/dev/zero seek=64G bs=1 count=1 of=huge
  touch -d @68719476737 huge
  tar cf - --format=pax |
  head -c 2048

using GNU tar. Note that this is not a complete tarfile, but
it's enough to contain the headers we want to examine.

Likewise, we need to convince git that it has a 64GB blob to
output. Running "git add" on that 64GB file takes many
minutes of CPU, and even compressed, the result is 64MB. So
again, I pre-generated that loose object, and then took only
the first 2k of it. That should be enough to generate 2MB of
data before hitting an inflate error, which is plenty for us
to generate the tar header (and then die of SIGPIPE while
streaming the rest out).

The tests are split so that we test as much as we can even
with an uncooperative system tar. This actually catches the
current breakage (which is that we die("BUG") trying to
write the ustar header) on every system, and then on systems
where we can, we go farther and actually verify the result.

Helped-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 10:24:18 -07:00
Jeff King
48860819e8 t9300: factor out portable "head -c" replacement
It is sometimes useful to be able to read exactly N bytes from a
pipe. Doing this portably turns out to be surprisingly difficult
in shell scripts.

We want a solution that:

  - is portable

  - never reads more than N bytes due to buffering (which
    would mean those bytes are not available to the next
    program to read from the same pipe)

  - handles partial reads by looping until N bytes are read
    (or we see EOF)

  - is resilient to stray signals giving us EINTR while
    trying to read (even though we don't send them, things
    like SIGWINCH could cause apparently-random failures)

Some possible solutions are:

  - "head -c" is not portable, and implementations may
    buffer (though GNU head does not)

  - "read -N" is a bash-ism, and thus not portable

  - "dd bs=$n count=1" does not handle partial reads. GNU dd
    has iflags=fullblock, but that is not portable

  - "dd bs=1 count=$n" fixes the partial read problem (all
    reads are 1-byte, so there can be no partial response).
    It does make a lot of write() calls, but for our tests
    that's unlikely to matter.  It's fairly portable. We
    already use it in our tests, and it's unlikely that
    implementations would screw up any of our criteria. The
    most unknown one would be signal handling.

  - perl can do a sysread() loop pretty easily. On my Linux
    system, at least, it seems to restart the read() call
    automatically. If that turns out not to be portable,
    though, it would be easy for us to handle it.

That makes the perl solution the least bad (because we
conveniently omitted "length of code" as a criterion).
It's also what t9300 is currently using, so we can just pull
the implementation from there.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 10:17:39 -07:00