Commit Graph

53446 Commits

Author SHA1 Message Date
Ben Peart
abb4bb8384 read-cache: load cache extensions on a worker thread
This patch helps address the CPU cost of loading the index by loading
the cache extensions on a worker thread in parallel with loading the cache
entries.

In some cases, loading the extensions takes longer than loading the
cache entries so this patch utilizes the new EOIE to start the thread to
load the extensions before loading all the cache entries in parallel.

This is possible because the current extensions don't access the cache
entries in the index_state structure so are OK that they don't all exist
yet.

The CACHE_EXT_TREE, CACHE_EXT_RESOLVE_UNDO, and CACHE_EXT_UNTRACKED
extensions don't even get a pointer to the index so don't have access to the
cache entries.

CACHE_EXT_LINK only uses the index_state to initialize the split index.
CACHE_EXT_FSMONITOR only uses the index_state to save the fsmonitor last
update and dirty flags.

I used p0002-read-cache.sh to generate some performance data:

	Test w/100,000 files reduced the time by 0.53%
	Test w/1,000,000 files reduced the time by 27.78%

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
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
Ben Peart
371ed0defa read-cache: clean up casting and byte decoding
This patch does a clean up pass to minimize the casting required to work
with the memory mapped index (mmap).

It also makes the decoding of network byte order more consistent by using
get_be32() where possible.

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
Rasmus Villemoes
912104770d git-help.txt: document "git help cmd" vs "git cmd --help" for aliases
This documents the existing behaviour of "git help cmd" when cmd is an
alias, as well as providing a hint to use the "git cmd --help" form to
be taken directly to the man page for the aliased command.

Signed-off-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 10:21:44 +09:00
Rasmus Villemoes
a9a60b94cc git.c: handle_alias: prepend alias info when first argument is -h
Most git commands respond to -h anywhere in the command line, or at
least as a first and lone argument, by printing the usage
information. For aliases, we can provide a little more information that
might be useful in interpreting/understanding the following output by
prepending a line telling that the command is an alias, and for what.

When one invokes a simple alias, such as "cp = cherry-pick"
with -h, this results in

$ git cp -h
'cp' is aliased to 'cherry-pick'
usage: git cherry-pick [<options>] <commit-ish>...
...

When the alias consists of more than one word, this provides the
additional benefit of informing the user which options are implicit in
using the alias, e.g. with "cp = cherry-pick -n":

$ git cp -h
'cp' is aliased to 'cherry-pick -n'
usage: git cherry-pick [<options>] <commit-ish>...
...

For shell commands, we cannot know how it responds to -h, but printing
this line to stderr should not hurt, and can help in figuring out what
is happening in a case like

$ git sc -h
'sc' is aliased to '!somecommand'
somecommand: invalid option '-h'

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 10:21:43 +09:00
Rasmus Villemoes
e6e76baaf4 help: redirect to aliased commands for "git cmd --help"
As discussed in the thread for v1 of this patch [1] [2], this changes the
rules for "git foo --help" when foo is an alias.

(1) When invoked as "git help foo", we continue to print the "foo is
aliased to bar" message and nothing else.

(2) If foo is an alias for a shell command, print "foo is aliased to
!bar" as usual.

(3) Otherwise, print "foo is aliased to bar" to the standard error
stream, and then break the alias string into words and pretend as if
"git word[0] --help" were called.

Getting the man page for git-cherry-pick directly with "git cp --help"
is consistent with "--help" generally providing more comprehensive help
than "-h". Printing the alias definition to stderr means that in certain
cases (e.g. if help.format=web or if the pager uses an alternate screen
and does not clear the terminal), one has

'cp' is aliased to 'cherry-pick -n'

above the prompt when one returns to the terminal/quits the pager, which
is a useful reminder that using 'cp' has some flag implicitly set. There
are cases where this information vanishes or gets scrolled
away, but being printed to stderr, it should never hurt.

[1] https://public-inbox.org/git/20180926102636.30691-1-rv@rasmusvillemoes.dk/
[2] https://public-inbox.org/git/20180926184914.GC30680@sigill.intra.peff.net/

Signed-off-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 10:21:41 +09:00
Mihir Mehta
ca8ed443a5 doc: fix a typo and clarify a sentence
I noticed that git-merge-base was unlikely to actually be a git command,
and tried it in my shell. Seeing that it doesn't work, I cleaned up two
places in the docs where it appears.

Signed-off-by: Mihir Mehta <mihir@cs.utexas.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-11 09:39:15 +09:00
Junio C Hamano
5a0cc8aca7 Third batch for 2.20
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-10 12:38:03 +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
Junio C Hamano
d555663f16 Merge branch 'bc/hash-independent-tests'
Various tests have been updated to make it easier to swap the
hash function used for object identification.

* bc/hash-independent-tests:
  t5318: use test_oid for HASH_LEN
  t1407: make hash size independent
  t1406: make hash-size independent
  t1405: make hash size independent
  t1400: switch hard-coded object ID to variable
  t1006: make hash size independent
  t0064: make hash size independent
  t0002: abstract away SHA-1 specific constants
  t0000: update tests for SHA-256
  t0000: use hash translation table
  t: add test functions to translate hash-related values
2018-10-10 12:37:16 +09:00
Junio C Hamano
77b5046ae3 Merge branch 'nd/test-tool'
Test helper binaries clean-up.

* nd/test-tool:
  Makefile: add a hint about TEST_BUILTINS_OBJS
  t/helper: merge test-dump-fsmonitor into test-tool
  t/helper: merge test-parse-options into test-tool
  t/helper: merge test-pkt-line into test-tool
  t/helper: merge test-dump-untracked-cache into test-tool
  t/helper: keep test-tool command list sorted
2018-10-10 12:37:16 +09:00
Junio C Hamano
3ba371f9df Merge branch 'nd/config-split'
Split Documentation/config.txt for easier maintenance.

* nd/config-split:
  config.txt: move submodule part out to a separate file
  config.txt: move sequence.editor out of "core" part
  config.txt: move sendemail part out to a separate file
  config.txt: move receive part out to a separate file
  config.txt: move push part out to a separate file
  config.txt: move pull part out to a separate file
  config.txt: move gui part out to a separate file
  config.txt: move gitcvs part out to a separate file
  config.txt: move format part out to a separate file
  config.txt: move fetch part out to a separate file
  config.txt: follow camelCase naming
2018-10-10 12:37:15 +09:00
Jonathan Tan
2f215ff10b cache-tree: skip some blob checks in partial clone
In a partial clone, whenever a sparse checkout occurs, the existence of
all blobs in the index is verified, whether they are included or
excluded by the .git/info/sparse-checkout specification. This
significantly degrades performance because a lazy fetch occurs whenever
the existence of a missing blob is checked.

This is because cache_tree_update() checks the existence of all objects
in the index, whether or not CE_SKIP_WORKTREE is set on them. Teach
cache_tree_update() to skip checking CE_SKIP_WORKTREE objects when the
repository is a partial clone. This improves performance for sparse
checkout and also other operations that use cache_tree_update().

Instead of completely removing the check, an argument could be made that
the check should instead be replaced by a check that the blob is
promised, but for performance reasons, I decided not to do this.
If the user needs to verify the repository, it can be done using fsck
(which will notify if a tree points to a missing and non-promised blob,
whether the blob is included or excluded by the sparse-checkout
specification).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-10 10:20:43 +09:00
Derrick Stolee
783faedd65 contrib: add coverage-diff script
We have coverage targets in our Makefile for using gcov to display line
coverage based on our test suite. The way I like to do it is to run:

    make coverage-test
    make coverage-report

This leaves the repo in a state where every X.c file that was covered has
an X.c.gcov file containing the coverage counts for every line, and "#####"
at every uncovered line.

There have been a few bugs in recent patches what would have been caught
if the test suite covered those blocks (including a few of mine). I want
to work towards a "sensible" amount of coverage on new topics. In my opinion,
this means that any logic should be covered, but the 'die()' blocks covering
very unlikely (or near-impossible) situations may not warrant coverage.

It is important to not measure the coverage of the codebase by what old code
is not covered. To help, I created the 'contrib/coverage-diff.sh' script.
After creating the coverage statistics at a version (say, 'topic') you can
then run

    contrib/coverage-diff.sh base topic

to see the lines added between 'base' and 'topic' that are not covered by the
test suite. The output uses 'git blame -s' format so you can find the commits
responsible and view the line numbers for quick access to the context, but
trims leading tabs in the file contents to reduce output width.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-10 10:11:35 +09:00
Junio C Hamano
2efbb7f521 Declare that the next one will be named 2.20
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-10 09:20:03 +09:00
brian m. carlson
b548d698a0 editorconfig: indicate settings should be kept in sync
Now that we have two places where we set code formatting settings,
.editorconfig and .clang-format, it's possible that they could fall out
of sync.  This is relatively unlikely, since we're not likely to change
the tab width or our preference for tabs, but just in case, add comments
to both files reminding future developers to keep them in sync.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 18:34:15 +09:00
brian m. carlson
6f9beef335 editorconfig: provide editor settings for Git developers
Contributors to Git use a variety of editors, each with their own
configuration files.  Because C lacks the defined norms on how to indent
and style code that other languages, such as Ruby and Rust, have, it's
possible for various contributors, especially new ones, to have
configured their editor to use a style other than the style the Git
community prefers.

To make automatically configuring one's editor easier, provide an
EditorConfig file.  This is an INI-style configuration file that can be
used to specify editor settings and can be understood by a wide variety
of editors.  Some editors include this support natively; others require
a plugin.  Regardless, providing such a file allows users to
automatically configure their editor of choice with the correct settings
by default.

Provide global settings to set the character set to UTF-8 and insert a
final newline into files.  Provide language-specific settings for C,
Shell, Perl, and Python files according to what CodingGuidelines already
specifies.  Since the indentation of other files varies, especially
certain AsciiDoc files, don't provide any settings for them until a
clear consensus forward emerges.

Set the line length for commit messages to 72 characters, which is the
generally accepted line length for emails, since we send patches by
email.

Don't specify an end of line type.  While the Git community uses
Unix-style line endings in the repository, some Windows users may use
Git's auto-conversion support and forcing Unix-style line endings might
cause problems for those users.

Finally, leave out a root directive, which would prevent reading other
EditorConfig files higher up in the tree, in case someone wants to set
the end of line type for their system in such a file.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 18:33:57 +09:00
Taylor Blau
40f327faf5 transport.c: introduce core.alternateRefsPrefixes
The recently-introduced "core.alternateRefsCommand" allows callers to
specify with high flexibility the tips that they wish to advertise from
alternates. This flexibility comes at the cost of some inconvenience
when the caller only wishes to limit the advertisement to one or more
prefixes.

For example, to advertise only tags, a caller using
'core.alternateRefsCommand' would have to do:

  $ git config core.alternateRefsCommand ' \
      f() { git -C "$1" for-each-ref \
              refs/tags --format="%(objectname)" }; f "$@"'

The above is cumbersome to write, so let's introduce a
"core.alternateRefsPrefixes" to address this common case. Instead, the
caller can run:

  $ git config core.alternateRefsPrefixes 'refs/tags'

Which will behave identically to the longer example using
"core.alternateRefsCommand".

Since the value of "core.alternateRefsPrefixes" is appended to 'git
for-each-ref' and then executed, include a "--" before taking the
configured value to avoid misinterpreting arguments as flags to 'git
for-each-ref'.

In the case that the caller wishes to specify multiple prefixes, they
may separate them by whitespace. If "core.alternateRefsCommand" is set,
it will take precedence over "core.alternateRefsPrefixes".

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 14:30:03 +09:00
Taylor Blau
89284c1d6c transport.c: introduce core.alternateRefsCommand
When in a repository containing one or more alternates, Git would
sometimes like to list references from those alternates. For example,
'git receive-pack' lists the "tips" pointed to by references in those
alternates as special ".have" references.

Listing ".have" references is designed to make pushing changes from
upstream to a fork a lightweight operation, by advertising to the pusher
that the fork already has the objects (via its alternate). Thus, the
client can avoid sending them.

However, when the alternate (upstream, in the previous example) has a
pathologically large number of references, the initial advertisement is
too expensive. In fact, it can dominate any such optimization where the
pusher avoids sending certain objects.

Introduce "core.alternateRefsCommand" in order to provide a facility to
limit or filter alternate references. This can be used, for example, to
filter out references the alternate does not wish to send (for space
concerns, or otherwise) during the initial advertisement.

Let the repository that has alternates configure this command to avoid
trusting the alternate to provide us a safe command to run in the shell.
To find the alternate, pass its absolute path as the first argument.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 14:30:03 +09:00
Taylor Blau
1e5f31d444 transport.c: extract 'fill_alternate_refs_command'
To list alternate references, 'read_alternate_refs' creates a child
process running 'git for-each-ref' in the alternate's Git directory.

Prepare to run other commands besides 'git for-each-ref' by introducing
and moving the relevant code from 'read_alternate_refs' to
'fill_alternate_refs_command'.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 14:30:03 +09:00
Jeff King
bdf4276c91 transport: drop refnames from for_each_alternate_ref
None of the current callers use the refname parameter we pass to their
callbacks. In theory somebody _could_ do so, but it's actually quite
weird if you think about it: it's a ref in somebody else's repository.
So the name has no meaning locally, and in fact there may be duplicates
if there are multiple alternates.

The users of this interface really only care about seeing some ref tips,
since that promises that the alternate has the full commit graph
reachable from there. So let's keep the information we pass back to the
bare minimum.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-09 14:30:02 +09:00
Michael Witten
ad0b8f9575 docs: typo: s/isimilar/similar/
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 10:11:02 +09:00
Michael Witten
634dbd0ad8 docs: graph: remove unnecessary `graph_update()' call
The sample code calls `get_revision()' followed by `graph_update()',
but the documentation and source code indicate that `get_revision()'
already calls `graph_update()' for you.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 10:10:49 +09:00
Michael Witten
42ce44e00a docs: typo: s/go/to/
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 10:10:42 +09:00
Steven Fernandez
705f5f122c git-completion.bash: add completion for stash list
Since stash list accepts git-log options, add the following useful
options that make sense in the context of the `git stash list` command:

  --name-status --oneline --patch-with-stat

Signed-off-by: Steven Fernandez <steve@lonetwin.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 10:05:49 +09:00
Jonathan Tan
e70a3030e7 fetch: do not list refs if fetching only hashes
If only hash literals are given on a "git fetch" command-line, tag
following is not requested, and the fetch is done using protocol v2, a
list of refs is not required from the remote. Therefore, optimize by
invoking transport_get_remote_refs() only if we need the refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 09:53:21 +09:00
Jonathan Tan
6ab4055775 transport: list refs before fetch if necessary
The built-in bundle transport and the transport helper interface do not
work when transport_fetch_refs() is called immediately after transport
creation. This will be needed in a subsequent patch, so fix this.

Evidence: fetch_refs_from_bundle() relies on data->header being
initialized in get_refs_from_bundle(), and fetch() in transport-helper.c
relies on either data->fetch or data->import being set by get_helper(),
but neither transport_helper_init() nor fetch() calls get_helper().

Up until the introduction of the partial clone feature, this has not
been a problem, because transport_fetch_refs() is always called after
transport_get_remote_refs(). With the introduction of the partial clone
feature, which involves calling transport_fetch_refs() (to fetch objects
by their OIDs) without transport_get_remote_refs(), this is still not a
problem, but only coincidentally - we do not support partially cloning a
bundle, and as for cloning using a transport-helper-using protocol, it
so happens that before transport_fetch_refs() is called, fetch_refs() in
fetch-object.c calls transport_set_option(), which means that the
aforementioned get_helper() is invoked through set_helper_option() in
transport-helper.c.

This could be fixed by fixing the transports themselves, but it doesn't
seem like a good idea to me to open up previously untested code paths;
also, there may be transport helpers in the wild that assume that "list"
is always called before "fetch". Instead, fix this by having
transport_fetch_refs() call transport_get_remote_refs() to ensure that
the latter is always called at least once, unless the transport
explicitly states that it supports fetching without listing refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 09:53:19 +09:00
Jonathan Tan
0177565148 transport: do not list refs if possible
When all refs to be fetched are exact OIDs, it is possible to perform a
fetch without requiring the remote to list refs if protocol v2 is used.
Teach Git to do this.

This currently has an effect only for lazy fetches done from partial
clones. The change necessary to likewise optimize "git fetch <remote>
<sha-1>" will be done in a subsequent patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 09:53:15 +09:00
Jonathan Tan
99bcb883cb transport: allow skipping of ref listing
The get_refs_via_connect() function both performs the handshake
(including determining the protocol version) and obtaining the list of
remote refs. However, the fetch protocol v2 supports fetching objects
without the listing of refs, so make it possible for the user to skip
the listing by creating a new handshake() function. This will be used in
a subsequent commit.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 09:35:41 +09:00
Matthew DeVore
8d6ba49563 tests: order arguments to git-rev-list properly
It is a common mistake to put positional arguments before flags when
invoking git-rev-list. Order the positional arguments last.

This patch skips git-rev-list invocations which include the --not flag,
since the ordering of flags and positional arguments affects the
behavior. This patch also skips invocations of git-rev-list that occur
in command substitution in which the exit code is discarded, since
fixing those properly will require a more involved cleanup.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:18 +09:00
Matthew DeVore
b00b6ace5c t9109: don't swallow Git errors upstream of pipes
'git ... | foo' will mask any errors or crashes in git, so split up such
pipes in this file.

One testcase uses several separate pipe sequences in a row which are
awkward to split up. Wrap the split-up pipe in a function so the
awkwardness is not repeated. Also change that testcase's surrounding
quotes from double to single to avoid premature string interpolation.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:18 +09:00
Matthew DeVore
61de0ff695 tests: don't swallow Git errors upstream of pipes
Some pipes in tests lose the exit code of git processes, which can mask
unexpected behavior like crashes. Split these pipes up so that git
commands are only at the end of pipes rather than the beginning or
middle.

The violations fixed in this patch were found in the process of fixing
pipe placement in a prior patch.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:18 +09:00
Matthew DeVore
dcbaa0b361 t/*: fix ordering of expected/observed arguments
Fix various places where the ordering was obviously wrong, meaning it
was easy to find with grep.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:18 +09:00
Matthew DeVore
bdbc17e86a tests: standardize pipe placement
Instead of using a line-continuation and pipe on the second line, take
advantage of the shell's implicit line continuation after a pipe
character.  So for example, instead of

	some long line \
		| next line

use

	some long line |
	next line

And add a blank line before and after the pipe where it aids readability
(it usually does).

This better matches the coding style documented in
Documentation/CodingGuidelines and used in shell scripts elsewhere in
the tree.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:18 +09:00
Matthew DeVore
a378fee5b0 Documentation: add shell guidelines
Add the following guideline to Documentation/CodingGuidelines:

	Break overlong lines after "&&", "||", and "|", not before
	them; that way the command can continue to subsequent lines
	without backslash at the end.

And the following to t/README (since it is specific to writing tests):

	Pipes and $(git ...) should be avoided when they swallow exit
	codes of Git processes

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:17 +09:00
Matthew DeVore
441ee35d83 t/README: reformat Do, Don't, Keep in mind lists
The list of Don'ts for test writing has grown large such that it is hard
to see at a glance which section an item is in. In other words, if I
ignore a little bit of surrounding context, the "don'ts" look like
"do's."

To make the list more readable, prefix "Don't" in front of every first
sentence in the items.

Also, the "Keep in mind" list is out of place and awkward, because it
was a very short "list" beneath two very long ones, and it seemed easy
to miss under the list of "don'ts," and it only had one item. So move
this item to the list of "do's" and phrase as "Remember..."

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:51:17 +09:00
Derrick Stolee
53c36670e7 commit-graph: reduce initial oid allocation
While writing a commit-graph file, we store the full list of
commits in a flat list. We use this list for sorting and ensuring
we are closed under reachability.

The initial allocation assumed that (at most) one in four objects
is a commit. This is a dramatic over-count for many repos,
especially large ones. Since we grow the repo dynamically, reduce
this count by a factor of eight. We still set it to a minimum of
1024 before allocating.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:25:05 +09:00
Martin Ågren
0bfb48e672 builtin/commit-graph.c: UNLEAK variables
`graph_verify()`, `graph_read()` and `graph_write()` do the hard work of
`cmd_commit_graph()`. As soon as these return, so does
`cmd_commit_graph()`.

`strbuf_getline()` may allocate memory in the strbuf, yet return EOF.
We need to release the strbuf or UNLEAK it. Go for the latter since we
are close to returning from `graph_write()`.

`graph_write()` also fails to free the strings in the string list. They
have been added to the list with `strdup_strings` set to 0. We could
flip `strdup_strings` before clearing the list, which is our usual hack
in situations like this. But since we are about to exit, let's just
UNLEAK the whole string list instead.

UNLEAK `graph` in `graph_verify`. While at it, and for consistency,
UNLEAK in `graph_read()` as well, and remove an unnecessary UNLEAK just
before dying.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:25:05 +09:00
Derrick Stolee
f4dbdfc4d5 commit-graph: clean up leaked memory during write
The write_commit_graph() method in commit-graph.c leaks some lits
and strings during execution. In addition, a list of strings is
leaked in write_commit_graph_reachable(). Clean these up so our
memory checking is cleaner.

Further, if we use a list of pack-files to find the commits, we
can leak the packed_git structs after scanning them for commits.

Running the following commands demonstrates the leak before and
the fix after:

* valgrind --leak-check=full ./git commit-graph write --reachable
* valgrind --leak-check=full ./git commit-graph write --stdin-packs

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:25:05 +09:00
Strain, Roger L
68f8ff8151 subtree: improve decision on merges kept in split
When multiple identical parents are detected for a commit being considered
for copying, explicitly check whether one is the common merge base between
the commits. If so, the other commit can be used as the identical parent;
if not, a merge must be performed to maintain history.

In some situations two parents of a merge commit may appear to both have
identical subtree content with each other and the current commit. However,
those parents can potentially come from different commit graphs.

Previous behavior would simply select one of the identical parents to
serve as the replacement for this commit, based on the order in which they
were processed.

New behavior compares the merge base between the commits to determine if
a new merge commit is necessary to maintain history despite the identical
content.

Signed-off-by: Strain, Roger L <roger.strain@swri.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:09:34 +09:00
Strain, Roger L
315a84f9aa subtree: use commits before rejoins for splits
Adds recursive evaluation of parent commits which were not part of the
initial commit list when performing a split.

Split expects all relevant commits to be reachable from the target commit
but not reachable from any previous rejoins. However, a branch could be
based on a commit prior to a rejoin, then later merged back into the
current code. In this case, a parent to the commit will not be present in
the initial list of commits, trigging an "incorrect order" warning.

Previous behavior was to consider that commit to have no parent, creating
an original commit containing all subtree content. This commit is not
present in an existing subtree commit graph, changing commit hashes and
making pushing to a subtree repo impossible.

New behavior will recursively check these unexpected parent commits to
track them back to either an earlier rejoin, or a true original commit.
The generated synthetic commits will properly match previously-generated
commits, allowing successful pushing to a prior subtree repo.

Signed-off-by: Strain, Roger L <roger.strain@swri.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:09:34 +09:00
Strain, Roger L
dd21d43b58 subtree: make --ignore-joins pay attention to adds
Changes the behavior of --ignore-joins to always consider a subtree add
commit, and ignore only splits and squashes.

The --ignore-joins option is documented to ignore prior --rejoin commits.
However, it additionally ignored subtree add commits generated when a
subtree was initially added to a repo.

Due to the logic which determines whether a commit is a mainline commit
or a subtree commit (namely, the presence or absence of content in the
subtree prefix) this causes commits before the initial add to appear to
be part of the subtree. An --ignore-joins split would therefore consider
those commits part of the subtree history and include them at the
beginning of the synthetic history, causing the resulting hashes to be
incorrect for all later commits.

Signed-off-by: Strain, Roger L <roger.strain@swri.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:09:34 +09:00
Strain, Roger L
565e4b7981 subtree: refactor split of a commit into standalone method
In a particularly complex repo, subtree split was not creating
compatible splits for pushing back to a separate repo. Addressing
one of the issues requires recursive handling of parent commits
that were not initially considered by the algorithm. This commit
makes no functional changes, but relocates the code to be called
recursively into a new method to simply comparisons of later
commits.

Signed-off-by: Strain, Roger L <roger.strain@swri.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-07 08:09:34 +09:00
Phillip Wood
47cb16a264 diff --color-moved: fix a memory leak
Free the hashmap items as well as the hashmap itself. This was found
with asan.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 22:48:21 -07:00
Phillip Wood
9c1a6c2bf8 diff --color-moved-ws: fix another memory leak
This is obvious in retrospect, it was found with asan.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 22:48:17 -07:00
Phillip Wood
fe4516d103 diff --color-moved-ws: fix a memory leak
Don't duplicate the indentation string if we're not going to use it.
This was found with asan.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 22:48:12 -07:00
Phillip Wood
cf074a9b0e diff --color-moved-ws: fix out of bounds string access
When adjusting the start of the string to take account of the change
in indentation the code was not checking that the string being
adjusted was in fact longer than the indentation change. This was
detected by asan.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 22:48:07 -07:00
Phillip Wood
74d156f4a1 diff --color-moved-ws: fix double free crash
Running

  git diff --color-moved-ws=allow-indentation-change v2.18.0 v2.19.0

results in a crash due to a double free. This happens when two
potential moved blocks start with consecutive lines. As
pmb_advance_or_null_multi_match() advances it copies the ws_delta from
the last matching line to the next. When the first of our consecutive
lines is advanced its ws_delta well be copied to the second,
overwriting the ws_delta of the block containing the second line. Then
when the second line is advanced it will copy the new ws_delta to the
line below it and so on. Eventually one of these blocks will stop
matching and the ws_delta will be freed. From then on the other block
is in a use-after-free state and when it stops matching it will try to
free the ws_delta that has already been freed by the other block.

The solution is to store the ws_delta in the array of potential moved
blocks rather than with the lines. This means that it no longer needs
to be copied around and one block cannot overwrite the ws_delta of
another. Additionally it saves some malloc/free calls as we don't keep
allocating and freeing ws_deltas.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 22:47:26 -07:00