Commit Graph

14247 Commits

Author SHA1 Message Date
Junio C Hamano
11914675aa Merge branch 'jk/test-tool-help'
Developer support.

* jk/test-tool-help:
  test-tool: show tool list on error
2018-10-30 15:43:44 +09:00
Junio C Hamano
620b00e167 Merge branch 'js/pack-objects-mutex-init-fix'
A mutex used in "git pack-objects" were not correctly initialized
and this caused "git repack" to dump core on Windows.

* js/pack-objects-mutex-init-fix:
  pack-objects (mingw): initialize `packing_data` mutex in the correct spot
  pack-objects (mingw): demonstrate a segmentation fault with large deltas
  pack-objects: fix typo 'detla' -> 'delta'
2018-10-30 15:43:43 +09:00
Junio C Hamano
17809a98f9 Merge branch 'jk/run-command-notdot'
The implementation of run_command() API on the UNIX platforms had a
bug that caused a command not on $PATH to be found in the current
directory.

* jk/run-command-notdot:
  run-command: mark path lookup errors with ENOENT
2018-10-30 15:43:41 +09:00
Junio C Hamano
107b9bad95 Merge branch 'tb/filter-alternate-refs'
Test fix.

* tb/filter-alternate-refs:
  t5410: use longer path for sample script
  Documentation/config.txt: fix typo in core.alternateRefsCommand
2018-10-30 15:43:41 +09:00
Junio C Hamano
d450e56423 Merge branch 'lm/range-diff-submodule-fix'
"git range-diff" did not work well when the compared ranges had
changes in submodules and the "--submodule=log" was used.

* lm/range-diff-submodule-fix:
  range-diff: allow to diff files regardless of submodule config
2018-10-30 15:43:40 +09:00
Junio C Hamano
77d503757d Merge branch 'md/filter-trees'
The "rev-list --filter" feature learned to exclude all trees via
"tree:0" filter.

* md/filter-trees:
  list-objects: support for skipping tree traversal
  filter-trees: code clean-up of tests
  list-objects-filter: implement filter tree:0
  list-objects-filter-options: do not over-strbuf_init
  list-objects-filter: use BUG rather than die
  revision: mark non-user-given objects instead
  rev-list: handle missing tree objects properly
  list-objects: always parse trees gently
  list-objects: refactor to process_tree_contents
  list-objects: store common func args in struct
2018-10-30 15:43:39 +09:00
Junio C Hamano
1e5d454856 Merge branch 'ld/p4-unshelve'
"git p4 unshelve" improvements.

* ld/p4-unshelve:
  git-p4: fully support unshelving changelists
  git-p4: unshelve into refs/remotes/p4-unshelved, not refs/remotes/p4/unshelved
  git-p4: do not fail in verbose mode for missing 'fileSize' key
2018-10-26 14:22:15 +09:00
Junio C Hamano
0ffa31fc36 Merge branch 'np/log-graph-octopus-fix'
"git log --graph" showing an octopus merge sometimes miscounted the
number of display columns it is consuming to show the merge and its
parent commits, which has been corrected.

* np/log-graph-octopus-fix:
  log: fix coloring of certain octopus merge shapes
2018-10-26 14:22:11 +09:00
Junio C Hamano
7a43ab6fb2 Merge branch 'sg/split-index-racefix'
The codepath to support the experimental split-index mode had
remaining "racily clean" issues fixed.

* sg/split-index-racefix:
  split-index: BUG() when cache entry refers to non-existing shared entry
  split-index: smudge and add racily clean cache entries to split index
  split-index: don't compare cached data of entries already marked for split index
  split-index: count the number of deleted entries
  t1700-split-index: date back files to avoid racy situations
  split-index: add tests to demonstrate the racy split index problem
  t1700-split-index: document why FSMONITOR is disabled in this test script
2018-10-26 14:22:10 +09:00
Junio C Hamano
f766176663 Merge branch 'ma/t7005-bash-workaround'
Test fix.

* ma/t7005-bash-workaround:
  t7005-editor: quote filename to fix whitespace-issue
2018-10-26 14:22:09 +09:00
Lucas De Marchi
0e573e8fcc range-diff: allow to diff files regardless of submodule config
If we have `submodule.diff = log' in the configuration file
or `--submodule=log' is given as argument, range-diff fails
to compare both diffs and we only get the following output:

    Submodule a 0000000...0000000 (new submodule)

Even if the repository doesn't have any submodule.

That's because the mode in diff_filespec is not correct and when
flushing the diff, down in builtin_diff() we will enter the condition:

	if (o->submodule_format == DIFF_SUBMODULE_LOG &&
	    (!one->mode || S_ISGITLINK(one->mode)) &&
	    (!two->mode || S_ISGITLINK(two->mode))) {
		show_submodule_summary(o, one->path ? one->path : two->path,
				&one->oid, &two->oid,
				two->dirty_submodule);
		return;

It turns out that S_ISGITLINK will return true (mode == 0160000 here).
Similar thing happens if submodule.diff is "diff".

Do like it's done in grep.c when calling fill_filespec() and force it to
be recognized as a file by adding S_IFREG to the mode.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-25 14:47:53 +09:00
Jeff King
e6641d2fa6 t5410: use longer path for sample script
t5410 creates a sample script "alternate-refs", and sets
core.alternateRefsCommand to just "alternate-refs". That
shouldn't work, as "." is not in our $PATH, and so we should
not find it.

However, due to a bug in run-command.c, we sometimes find it
anyway! Even more confusing, this bug is only in the
fork-based version of run-command. So the test passes on
Linux (etc), but fails on Windows.

In preparation for fixing the run-command bug, let's use a
more complete path here.

Reported-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-25 11:44:34 +09:00
Junio C Hamano
f67b980771 t0061: adjust to test-tool transition 2018-10-25 11:41:09 +09:00
Jeff King
321fd82389 run-command: mark path lookup errors with ENOENT
Since commit e3a434468f (run-command: use the
async-signal-safe execv instead of execvp, 2017-04-19),
prepare_cmd() does its own PATH lookup for any commands we
run (on non-Windows platforms).

However, its logic does not match the old execvp call when
we fail to find a matching entry in the PATH. Instead of
feeding the name directly to execv, execvp would consider
that an ENOENT error. By continuing and passing the name
directly to execv, we effectively behave as if "." was
included at the end of the PATH. This can have confusing and
even dangerous results.

The fix itself is pretty straight-forward. There's a new
test in t0061 to cover this explicitly, and I've also added
a duplicate of the ENOENT test to ensure that we return the
correct errno for this case.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-25 11:06:51 +09:00
Johannes Schindelin
34204c8166 pack-objects (mingw): initialize packing_data mutex in the correct spot
In 9ac3f0e5b3 (pack-objects: fix performance issues on packing large
deltas, 2018-07-22), a mutex was introduced that is used to guard the
call to set the delta size. This commit even added code to initialize
it, but at an incorrect spot: in `init_threaded_search()`, while the
call to `oe_set_delta_size()` (and hence to `packing_data_lock()`) can
happen in the call chain `check_object()` <- `get_object_details()` <-
`prepare_pack()` <- `cmd_pack_objects()`, which is long before the
`prepare_pack()` function calls `ll_find_deltas()` (which initializes
the threaded search).

Another tell-tale that the mutex was initialized in an incorrect spot is
that the function to initialize it lives in builtin/, while the code
that uses the mutex is defined in a libgit.a header file.

Let's use a more appropriate function: `prepare_packing_data()`, which
not only lives in libgit.a, but *has* to be called before the
`packing_data` struct is used that contains that mutex.

This fixes https://github.com/git-for-windows/git/issues/1839.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-19 14:28:44 +09:00
Johannes Schindelin
9308f45a9f pack-objects (mingw): demonstrate a segmentation fault with large deltas
There is a problem in the way 9ac3f0e5b3 (pack-objects: fix
performance issues on packing large deltas, 2018-07-22) initializes that
mutex in the `packing_data` struct. The problem manifests in a
segmentation fault on Windows, when a mutex (AKA critical section) is
accessed without being initialized. (With pthreads, you apparently do
not really have to initialize them?)

This was reported in https://github.com/git-for-windows/git/issues/1839.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-19 14:28:44 +09:00
Junio C Hamano
a08b1d62b0 Merge branch 'jt/cache-tree-allow-missing-object-in-partial-clone'
In a partial clone that will lazily be hydrated from the
originating repository, we generally want to avoid "does this
object exist (locally)?" on objects that we deliberately omitted
when we created the clone.  The cache-tree codepath (which is used
to write a tree object out of the index) however insisted that the
object exists, even for paths that are outside of the partial
checkout area.  The code has been updated to avoid such a check.

* jt/cache-tree-allow-missing-object-in-partial-clone:
  cache-tree: skip some blob checks in partial clone
2018-10-19 13:34:08 +09:00
Junio C Hamano
465e73fff3 Merge branch 'tb/filter-alternate-refs'
When pushing into a repository that borrows its objects from an
alternate object store, "git receive-pack" that responds to the
push request on the other side lists the tips of refs in the
alternate to reduce the amount of objects transferred.  This
sometimes is detrimental when the number of refs in the alternate
is absurdly large, in which case the bandwidth saved in potentially
fewer objects transferred is wasted in excessively large ref
advertisement.  The alternate refs that are advertised are now
configurable with a pair of configuration variables.

* tb/filter-alternate-refs:
  transport.c: introduce core.alternateRefsPrefixes
  transport.c: introduce core.alternateRefsCommand
  transport.c: extract 'fill_alternate_refs_command'
  transport: drop refnames from for_each_alternate_ref
2018-10-19 13:34:08 +09:00
Junio C Hamano
0527fbab68 Merge branch 'jt/avoid-ls-refs'
Over some transports, fetching objects with an exact commit object
name can be done without first seeing the ref advertisements.  The
code has been optimized to exploit this.

* jt/avoid-ls-refs:
  fetch: do not list refs if fetching only hashes
  transport: list refs before fetch if necessary
  transport: do not list refs if possible
  transport: allow skipping of ref listing
2018-10-19 13:34:07 +09:00
Junio C Hamano
fa54cccf1f Merge branch 'jt/non-blob-lazy-fetch'
A partial clone that is configured to lazily fetch missing objects
will on-demand issue a "git fetch" request to the originating
repository to fill not-yet-obtained objects.  The request has been
optimized for requesting a tree object (and not the leaf blob
objects contained in it) by telling the originating repository that
no blobs are needed.

* jt/non-blob-lazy-fetch:
  fetch-pack: exclude blobs when lazy-fetching trees
  fetch-pack: avoid object flags if no_dependents
2018-10-19 13:34:07 +09:00
Junio C Hamano
9822b8f10d Merge branch 'rs/grep-no-recursive'
Unlike "grep", "git grep" by default recurses to the whole tree.
The command learned "git grep --recursive" option, so that "git
grep --no-recursive" can serve as a synonym to setting the
max-depth to 0.

* rs/grep-no-recursive:
  grep: add -r/--[no-]recursive
2018-10-19 13:34:06 +09:00
Junio C Hamano
54e564e1d6 Merge branch 'nd/help-commands-verbose-by-default'
"git help -a" and "git help -av" give different pieces of
information, and generally the "verbose" version is more friendly
to the new users.  "git help -a" by default now uses the more
verbose output (with "--no-verbose", you can go back to the
original).  Also "git help -av" now lists aliases and external
commands, which it did not used to.

* nd/help-commands-verbose-by-default:
  help -a: improve and make --verbose default
2018-10-19 13:34:05 +09:00
Junio C Hamano
d152a74e25 Merge branch 'sm/show-superproject-while-conflicted'
A corner-case bugfix.

* sm/show-superproject-while-conflicted:
  rev-parse: --show-superproject-working-tree should work during a merge
2018-10-19 13:34:04 +09:00
Junio C Hamano
a1e9dff182 Merge branch 'jt/fetch-tips-in-partial-clone'
"git fetch $repo $object" in a partial clone did not correctly
fetch the asked-for object that is referenced by an object in
promisor packfile, which has been fixed.

* jt/fetch-tips-in-partial-clone:
  fetch: in partial clone, check presence of targets
  connected: document connectivity in partial clones
2018-10-19 13:34:04 +09:00
Junio C Hamano
e27bfaaee3 Merge branch 'bp/read-cache-parallel'
A new extension to the index file has been introduced, which allows
the file to be read in parallel.

* bp/read-cache-parallel:
  read-cache: load cache entries on worker threads
  ieot: add Index Entry Offset Table (IEOT) extension
  read-cache: load cache extensions on a worker thread
  config: add new index.threads config setting
  eoie: add End of Index Entry (EOIE) extension
  read-cache: clean up casting and byte decoding
  read-cache.c: optimize reading index format v4
2018-10-19 13:34:03 +09:00
Junio C Hamano
340fde61be Merge branch 'bp/rename-test-env-var'
Some environment variables that control the runtime options of Git
used during tests are getting renamed for consistency.

* bp/rename-test-env-var:
  t0000: do not get self-test disrupted by environment warnings
  preload-index: update GIT_FORCE_PRELOAD_TEST support
  read-cache: update TEST_GIT_INDEX_VERSION support
  fsmonitor: update GIT_TEST_FSMONITOR support
  preload-index: use git_env_bool() not getenv() for customization
  t/README: correct spelling of "uncommon"
2018-10-19 13:34:03 +09:00
Junio C Hamano
929e85ade8 Merge branch 'ss/wt-status-committable'
Code clean-up in the internal machinery used by "git status" and
"git commit --dry-run".

* ss/wt-status-committable:
  roll wt_status_state into wt_status and populate in the collect phase
  wt-status.c: set the committable flag in the collect phase
  t7501: add test of "commit --dry-run --short"
  wt-status: rename commitable to committable
  wt-status.c: move has_unmerged earlier in the file
2018-10-19 13:34:02 +09:00
Junio C Hamano
11877b9ebe Merge branch 'nd/the-index'
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...
2018-10-19 13:34:02 +09:00
Matthew DeVore
8b10a206f0 list-objects: support for skipping tree traversal
The tree:0 filter does not need to traverse the trees that it has
filtered out, so optimize list-objects and list-objects-filter to skip
traversing the trees entirely. Before this patch, we iterated over all
children of the tree, and did nothing for all of them, which was
wasteful.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-18 12:49:18 +09:00
Jeff King
4e26569d98 test-tool: show tool list on error
Before we switched to one big test-tool binary, if you
forgot the name of a tool, you could use tab-completion in
the shell to get a hint. But these days, all you get is:

  $ t/helper/test-tool approxidate
  fatal: There is no test named 'approxidate'

and you're stuck reading the source code to find it. Let's
print a list of the available tools in this case.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-18 12:27:39 +09:00
Junio C Hamano
0e6450039a Merge branch 'ma/t1400-undebug-test'
Test fix.

* ma/t1400-undebug-test:
  t1400: drop debug `echo` to actually execute `test`
2018-10-16 16:16:06 +09:00
Junio C Hamano
98f3f007f5 Merge branch 'en/status-multiple-renames-to-the-same-target-fix'
The code in "git status" sometimes hit an assertion failure.  This
was caused by a structure that was reused without cleaning the data
used for the first run, which has been corrected.

* en/status-multiple-renames-to-the-same-target-fix:
  commit: fix erroneous BUG, 'multiple renames on the same target? how?'
2018-10-16 16:16:05 +09:00
Junio C Hamano
993fa56258 Merge branch 'jn/gc-auto'
"gc --auto" ended up calling exit(-1) upon error, which has been
corrected to use exit(1).  Also the error reporting behaviour when
daemonized has been updated to exit with zero status when stopping
due to a previously discovered error (which implies there is no
point running gc to improve the situation); we used to exit with
failure in such a case.

* jn/gc-auto:
  gc: do not return error for prior errors in daemonized mode
2018-10-16 16:16:02 +09:00
Junio C Hamano
99913dd118 Merge branch 'jn/gc-auto-prep'
Code clean-up.

* jn/gc-auto-prep:
  gc: exit with status 128 on failure
  gc: improve handling of errors reading gc.log
2018-10-16 16:16:02 +09:00
Junio C Hamano
f2e2136ad7 Merge branch 'md/test-cleanup'
Various test scripts have been updated for style and also correct
handling of exit status of various commands.

* md/test-cleanup:
  tests: order arguments to git-rev-list properly
  t9109: don't swallow Git errors upstream of pipes
  tests: don't swallow Git errors upstream of pipes
  t/*: fix ordering of expected/observed arguments
  tests: standardize pipe placement
  Documentation: add shell guidelines
  t/README: reformat Do, Don't, Keep in mind lists
2018-10-16 16:16:01 +09:00
Junio C Hamano
52472c20d2 Merge branch 'tg/t5551-with-curl-7.61.1'
Test update.

* tg/t5551-with-curl-7.61.1:
  t5551: compare sorted cookies files
  t5551: move setup code inside test_expect blocks
2018-10-16 16:16:00 +09:00
Junio C Hamano
506ee60d22 Merge branch 'ts/alias-of-alias'
An alias that expands to another alias has so far been forbidden,
but now it is allowed to create such an alias.

* ts/alias-of-alias:
  t0014: introduce an alias testing suite
  alias: show the call history when an alias is looping
  alias: add support for aliases of an alias
2018-10-16 16:15:59 +09:00
Junio C Hamano
6d8f8ebb74 Merge branch 'ds/commit-graph-with-grafts'
The recently introduced commit-graph auxiliary data is incompatible
with mechanisms such as replace & grafts that "breaks" immutable
nature of the object reference relationship.  Disable optimizations
based on its use (and updating existing commit-graph) when these
incompatible features are in use in the repository.

* ds/commit-graph-with-grafts:
  commit-graph: close_commit_graph before shallow walk
  commit-graph: not compatible with uninitialized repo
  commit-graph: not compatible with grafts
  commit-graph: not compatible with replace objects
  test-repository: properly init repo
  commit-graph: update design document
  refs.c: upgrade for_each_replace_ref to be a each_repo_ref_fn callback
  refs.c: migrate internal ref iteration to pass thru repository argument
2018-10-16 16:15:59 +09:00
Junio C Hamano
36d767d02e Merge branch 'ab/commit-graph-progress'
Generation of (experimental) commit-graph files have so far been
fairly silent, even though it takes noticeable amount of time in a
meaningfully large repository.  The users will now see progress
output.

* ab/commit-graph-progress:
  gc: fix regression in 7b0f229222 impacting --quiet
  commit-graph verify: add progress output
  commit-graph write: add progress output
2018-10-16 16:15:58 +09:00
Luke Diamand
89143ac28a git-p4: fully support unshelving changelists
The previous git-p4 unshelve support would check for changes
in Perforce to the files being unshelved since the original
shelve, and would complain if any were found.

This was to ensure that the user wouldn't end up with both the
shelved change delta, and some deltas from other changes in their
git commit.

e.g. given fileA:
      the
      quick
      brown
      fox

  change1: s/the/The/   <- p4 shelve this change
  change2: s/fox/Fox/   <- p4 submit this change
  git p4 unshelve 1     <- FAIL

This change teaches the P4Unshelve class to always create a parent
commit which matches the P4 tree (for the files being unshelved) at
the point prior to the P4 shelve being created (which is reported
in the p4 description for a shelved changelist).

That then means git-p4 can always create a git commit matching the
P4 shelve that was originally created, without any extra deltas.

The user might still need to use the --origin option though - there
is no way for git-p4 to work out the versions of all of the other
*unchanged* files in the shelve, since this information is not recorded
by Perforce.

Additionally this fixes handling of shelved 'move' operations.

Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-16 13:28:49 +09:00
Luke Diamand
088131273b git-p4: unshelve into refs/remotes/p4-unshelved, not refs/remotes/p4/unshelved
The branch detection code looks for branches under refs/remotes/p4/...
and can end up getting confused if there are unshelved changes in
there as well. This happens in the function p4BranchesInGit().

Instead, put the unshelved changes into refs/remotes/p4-unshelved/<N>.

Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-16 13:28:49 +09:00
Matthew DeVore
d9e6d0942b filter-trees: code clean-up of tests
A few trivial updates to test to match the current best practices.

 - avoid "grep -q" that strips potentially useful output from tests
   running under "-v".

 - use test_write_lines to prepare multi-line expected output file.

 - reserve use of test_must_fail to "git" commands.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-15 12:43:17 +09:00
Noam Postavsky
04005834ed log: fix coloring of certain octopus merge shapes
For octopus merges where the first parent edge immediately merges into
the next column to the left, the number of columns should be one less
than the usual case.

First parent to the left case:

| *-.
| |\ \
|/ / /

The usual case:

| *-.
| |\ \
| | | *

Also refactor the code to iterate over columns rather than dashes,
building from an initial patch suggested by Jeff King.

Signed-off-by: Noam Postavsky <npostavs@users.sourceforge.net>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-12 12:22:48 +09:00
SZEDER Gábor
5581a019ba split-index: smudge and add racily clean cache entries to split index
Ever since the split index feature was introduced [1], refreshing a
split index is prone to a variant of the classic racy git problem.

Consider the following sequence of commands updating the split index
when the shared index contains a racily clean cache entry, i.e. an
entry whose cached stat data matches with the corresponding file in
the worktree and the cached mtime matches that of the index:

  echo "cached content" >file
  git update-index --split-index --add file
  echo "dirty worktree" >file    # size stays the same!
  # ... wait ...
  git update-index --add other-file

Normally, when a non-split index is updated, then do_write_index()
(the function responsible for writing all kinds of indexes, "regular",
split, and shared) recognizes racily clean cache entries, and writes
them with smudged stat data, i.e. with file size set to 0.  When
subsequent git commands read the index, they will notice that the
smudged stat data doesn't match with the file in the worktree, and
then go on to check the file's content and notice its dirtiness.

In the above example, however, in the second 'git update-index'
prepare_to_write_split_index() decides which cache entries stored only
in the shared index should be replaced in the new split index.  Alas,
this function never looks out for racily clean cache entries, and
since the file's stat data in the worktree hasn't changed since the
shared index was written, it won't be replaced in the new split index.
Consequently, do_write_index() doesn't even get this racily clean
cache entry, and can't smudge its stat data.  Subsequent git commands
will then see that the index has more recent mtime than the file and
that the (not smudged) cached stat data still matches with the file in
the worktree, and, ultimately, will erroneously consider the file
clean.

Modify prepare_to_write_split_index() to recognize racily clean cache
entries, and mark them to be added to the split index.  Note that
there are two places where it should check raciness: first those cache
entries that are only stored in the shared index, and then those that
have been copied by unpack_trees() from the shared index while it
constructed a new index.  This way do_write_index() will get these
racily clean cache entries as well, and will then write them with
smudged stat data to the new split index.

This change makes all tests in 't1701-racy-split-index.sh' pass, so
flip the two 'test_expect_failure' tests to success.  Also add the '#'
(as in nr. of trial) to those tests' description that were omitted
when the tests expected failure.

Note that after this change if the index is split when it contains a
racily clean cache entry, then a smudged cache entry will be written
both to the new shared and to the new split indexes.  This doesn't
affect regular git commands: as far as they are concerned this is just
an entry in the split index replacing an outdated entry in the shared
index.  It did affect a few tests in 't1700-split-index.sh', though,
because they actually check which entries are stored in the split
index; a previous patch in this series has already made the necessary
adjustments in 't1700'.  And racily clean cache entries and index
splitting are rare enough to not worry about the resulting duplicated
smudged cache entries, and the additional complexity required to
prevent them is not worth it.

Several tests failed occasionally when the test suite was run with
'GIT_TEST_SPLIT_INDEX=yes'.  Here are those that I managed to trace
back to this racy split index problem, starting with those failing
more frequently, with a link to a failing Travis CI build job for
each.  The highlighted line [2] shows when the racy file was written,
which is not always in the failing test but in a preceeding setup
test.

  t3903-stash.sh:
    https://travis-ci.org/git/git/jobs/385542084#L5858

  t4024-diff-optimize-common.sh:
    https://travis-ci.org/git/git/jobs/386531969#L3174

  t4015-diff-whitespace.sh:
    https://travis-ci.org/git/git/jobs/360797600#L8215

  t2200-add-update.sh:
    https://travis-ci.org/git/git/jobs/382543426#L3051

  t0090-cache-tree.sh:
    https://travis-ci.org/git/git/jobs/416583010#L3679

There might be others, e.g. perhaps 't1000-read-tree-m-3way.sh' and
others using 'lib-read-tree-m-3way.sh', but I couldn't confirm yet.

[1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge
    branch 'nd/split-index', 2014-07-16).

[2] Note that those highlighted lines are in the 'after failure' fold,
    and your browser might unhelpfully fold it up before you could
    take a good look.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-12 07:23:29 +09:00
SZEDER Gábor
c6e5607c56 t1700-split-index: date back files to avoid racy situations
't1700-split-index.sh' checks that the index was split correctly under
various circumstances and that all the different ways to turn the
split index feature on and off work correctly.  To do so, most of its
tests use 'test-tool dump-split-index' to see which files have their
cache entries in the split index.  All these tests assume that all
cache entries are written to the shared index (called "base"
throughout these tests) when a new shared index is created.  This is
an implementation detail: most git commands (basically all except 'git
update-index') don't care or know at all about split index or whether
a cache entry is stored in the split or shared index.

As demonstrated in the previous patch, refreshing a split index is
prone to a variant of the classic racy git issue.  The next patch will
fix this issue, but while doing so it will also slightly change this
behaviour: only cache entries with mtime in the past will be written
only to the newly created shared index, but racily clean cache entries
will be written to the new split index (with smudged stat data).

While this upcoming change won't at all affect any git commands, it
will violate the above mentioned assumption of 't1700's tests.  Since
these tests create or modify files and create or refresh the split
index in rapid succession, there are plenty of racily clean cache
entries to be dealt with, which will then be written to the new split
indexes, and, ultimately, will cause several tests in 't1700' to fail.

Let's prepare 't1700-split-index.sh' for this upcoming change and
modify its tests to avoid racily clean files by backdating the mtime
of any file modifications (and since a lot of tests create or modify
files, encapsulate it into a helper function).

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-12 07:23:29 +09:00
SZEDER Gábor
74e8addfaa split-index: add tests to demonstrate the racy split index problem
Ever since the split index feature was introduced [1], refreshing a
split index is prone to a variant of the classic racy git problem.
There are a couple of unrelated tests in the test suite that
occasionally fail when run with 'GIT_TEST_SPLIT_INDEX=yes', but
't1700-split-index.sh', the only test script focusing solely on split
index, has never noticed this issue, because it only cares about how
the index is split under various circumstances and all the different
ways to turn the split index feature on and off.

Add a dedicated test script 't1701-racy-split-index.sh' to exercise
the split index feature in racy situations as well; kind of a
"t0010-racy-git.sh for split index" but with modern style (the tests
do everything in &&-chained list of commands in 'test_expect_...'
blocks, and use 'test_cmp' for more informative output on failure).

The tests cover the following sequences of index splitting, updating,
and racy file modifications, with the last two cases demonstrating the
racy split index problem:

  1. Split the index while adding a racily clean file:

       echo "cached content" >file
       git update-index --split-index --add file
       echo "dirty worktree" >file    # size stays the same

     This case already works properly.  Even though the cache entry's
     stat data matches with the modifid file in the worktree,
     subsequent git commands will notice that the (split) index and
     the file have the same mtime, and then will go on to check the
     file's content and notice its dirtiness.

  2. Add a racily clean file to an already split index:

       git update-index --split-index
       echo "cached content" >file
       git update-index --add file
       echo "dirty worktree" >file

     This case already works properly.  After the second 'git
     update-index' writes the newly added file's cache entry to the
     new split index, it basically works in the same way as case #1.

  3. Split the index when it (i.e. the not yet splitted index)
     contains a racily clean cache entry, i.e. an entry whose cached
     stat data matches with the corresponding file in the worktree and
     the cached mtime matches that of the index:

       echo "cached content" >file
       git update-index --add file
       echo "dirty worktree" >file
       # ... wait ...
       git update-index --split-index --add other-file

     This case already works properly.  The shared index is written by
     do_write_index(), i.e. the same function that is responsible for
     writing "regular" and split indexes as well.  This function
     cleverly notices the racily clean cache entry, and writes the
     entry to the new shared index with smudged stat data, i.e. file
     size set to 0.  When subsequent git commands read the index, they
     will notice that the smudged stat data doesn't match with the
     file in the worktree, and then go on to check the file's content
     and notice its dirtiness.

  4. Update the split index when it contains a racily clean cache
     entry:

       git update-index --split-index
       echo "cached content" >file
       git update-index --add file
       echo "dirty worktree" >file
       # ... wait ...
       git update-index --add other-file

     This case already works properly.  After the second 'git
     update-index' the newly added file's cache entry is only stored
     in the split index.  If a cache entry is present in the split
     index (even if it is a replacement of an outdated entry in the
     shared index), then it will always be included in the new split
     index on subsequent split index updates (until the file is
     removed or a new shared index is written), independently from
     whether the entry is racily clean or not.  When do_write_index()
     writes the new split index, it notices the racily clean cache
     entry, and smudges its stat date.  Subsequent git commands
     reading the index will notice the smudged stat data and then go
     on to check the file's content and notice its dirtiness.

  5. Update the split index when a racily clean cache entry is stored
     only in the shared index:

       echo "cached content" >file
       git update-index --split-index --add file
       echo "dirty worktree" >file
       # ... wait ...
       git update-index --add other-file

     This case fails due to the racy split index problem.  In the
     second 'git update-index' prepare_to_write_split_index() decides,
     among other things, which cache entries stored only in the shared
     index should be replaced in the new split index.  Alas, this
     function never looks out for racily clean cache entries, and
     since the file's stat data in the worktree hasn't changed since
     the shared index was written, the entry won't be replaced in the
     new split index.  Consequently, do_write_index() doesn't even get
     this racily clean cache entry, and can't smudge its stat data.
     Subsequent git commands will then see that the index has more
     recent mtime than the file and that the (not smudged) cached stat
     data still matches with the file in the worktree, and,
     ultimately, will erroneously consider the file clean.

  6. Update the split index after unpack_trees() copied a racily clean
     cache entry from the shared index:

       echo "cached content" >file
       git update-index --split-index --add file
       echo "dirty worktree" >file
       # ... wait ...
       git read-tree -m HEAD

     This case fails due to the racy split index problem.  This
     basically fails for the same reason as case #5 above, but there
     is one important difference, which warrants the dedicated test.
     While that second 'git update-index' in case #5 updates
     index_state in place, in this case 'git read-tree -m' calls
     unpack_trees(), which throws out the entire index, and constructs
     a new one from the (potentially updated) copies of the original's
     cache entries.  Consequently, when prepare_to_write_split_index()
     gets to work on this reconstructed index, it takes a different
     code path than in case #5 when deciding which cache entries in
     the shared index should be replaced.  The result is the same,
     though: the racily clean cache entry goes unnoticed, it isn't
     added to the split index with smudged stat data, and subsequent
     git commands will then erroneously consider the file clean.

Note that in the last two 'test_expect_failure' cases I omitted the
'#' (as in nr. of trial) from the tests' description on purpose for
now, as it breakes the TAP output [2]; it will be added at the end of
the series, when those two tests will be flipped to
'test_expect_success'.

[1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge
    branch 'nd/split-index', 2014-07-16).

[2] In the TAP output a '#' should separate the test's description
    from the TODO directive emitted by 'test_expect_failure'.  The
    additional '#' in "#$trial" interferes with this, the test harness
    won't recognize the TODO directive, and will report that those
    tests failed unexpectedly.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-12 07:23:29 +09:00
Ben Peart
c780b9cfe8 config: add new index.threads config setting
Add support for a new index.threads config setting which will be used to
control the threading code in do_read_index().  A value of 0 will tell the
index code to automatically determine the correct number of threads to use.
A value of 1 will make the code single threaded.  A value greater than 1
will set the maximum number of threads to use.

For testing purposes, this setting can be overwritten by setting the
GIT_TEST_INDEX_THREADS=<n> environment variable to a value greater than 0.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Ben Peart
3b1d9e045e eoie: add End of Index Entry (EOIE) extension
The End of Index Entry (EOIE) is used to locate the end of the variable
length index entries and the beginning of the extensions. Code can take
advantage of this to quickly locate the index extensions without having
to parse through all of the index entries.

The EOIE extension is always written out to the index file including to
the shared index when using the split index feature. Because it is always
written out, the SHA checksums in t/t1700-split-index.sh were updated
to reflect its inclusion.

It is written as an optional extension to ensure compatibility with other
git implementations that do not yet support it.  It is always written out
to ensure it is available as often as possible to speed up index operations.

Because it must be able to be loaded before the variable length cache
entries and other index extensions, this extension must be written last.
The signature for this extension is { 'E', 'O', 'I', 'E' }.

The extension consists of:

- 32-bit offset to the end of the index entries

- 160-bit SHA-1 over the extension types and their sizes (but not
their contents).  E.g. if we have "TREE" extension that is N-bytes
long, "REUC" extension that is M-bytes long, followed by "EOIE",
then the hash would be:

SHA-1("TREE" + <binary representation of N> +
    "REUC" + <binary representation of M>)

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 15:32:48 +09:00
Junio C Hamano
66ec2373fe Merge branch 'ab/fsck-skiplist'
Update fsck.skipList implementation and documentation.

* ab/fsck-skiplist:
  fsck: support comments & empty lines in skipList
  fsck: use oidset instead of oid_array for skipList
  fsck: use strbuf_getline() to read skiplist file
  fsck: add a performance test for skipList
  fsck: add a performance test
  fsck: document that skipList input must be unabbreviated
  fsck: document and test commented & empty line skipList input
  fsck: document and test sorted skipList input
  fsck tests: add a test for no skipList input
  fsck tests: setup of bogus commit object
2018-10-10 12:37:16 +09:00
Junio C Hamano
468b322137 Merge branch 'ds/multi-pack-verify'
"git multi-pack-index" learned to detect corruption in the .midx
file it uses, and this feature has been integrated into "git fsck".

* ds/multi-pack-verify:
  fsck: verify multi-pack-index
  multi-pack-index: report progress during 'verify'
  multi-pack-index: verify object offsets
  multi-pack-index: fix 32-bit vs 64-bit size check
  multi-pack-index: verify oid lookup order
  multi-pack-index: verify oid fanout order
  multi-pack-index: verify missing pack
  multi-pack-index: verify packname order
  multi-pack-index: verify corrupt chunk lookup table
  multi-pack-index: verify bad header
  multi-pack-index: add 'verify' verb
2018-10-10 12:37:16 +09:00