Operations that do not touch (majority of) packed refs have been
optimized by making accesses to packed-refs file lazy; we no longer
pre-parse everything, and an access to a single ref in the
packed-refs does not touch majority of irrelevant refs, either.
* mh/mmap-packed-refs: (21 commits)
packed-backend.c: rename a bunch of things and update comments
mmapped_ref_iterator: inline into `packed_ref_iterator`
ref_cache: remove support for storing peeled values
packed_ref_store: get rid of the `ref_cache` entirely
ref_store: implement `refs_peel_ref()` generically
packed_read_raw_ref(): read the reference from the mmapped buffer
packed_ref_iterator_begin(): iterate using `mmapped_ref_iterator`
read_packed_refs(): ensure that references are ordered when read
packed_ref_cache: keep the `packed-refs` file mmapped if possible
packed-backend.c: reorder some definitions
mmapped_ref_iterator_advance(): no peeled value for broken refs
mmapped_ref_iterator: add iterator over a packed-refs file
packed_ref_cache: remember the file-wide peeling state
read_packed_refs(): read references with minimal copying
read_packed_refs(): make parsing of the header line more robust
read_packed_refs(): only check for a header at the top of the file
read_packed_refs(): use mmap to read the `packed-refs` file
die_unterminated_line(), die_invalid_line(): new functions
packed_ref_cache: add a backlink to the associated `packed_ref_store`
prefix_ref_iterator: break when we leave the prefix
...
The output from "git diff --summary" was broken in a recent topic
that has been merged to 'master' and lost a LF after reporting of
mode change. This has been fixed.
* sb/diff-color-move:
diff: correct newline in summary for renamed files
Code clean-up.
* jk/validate-headref-fix:
validate_headref: use get_oid_hex for detached HEADs
validate_headref: use skip_prefix for symref parsing
validate_headref: NUL-terminate HEAD buffer
Code clean-up to prevent future mistakes by copying and pasting
code that checks the result of read_in_full() function.
* jk/read-in-full:
worktree: check the result of read_in_full()
worktree: use xsize_t to access file size
distinguish error versus short read from read_in_full()
avoid looking at errno for short read_in_full() returns
prefer "!=" when checking read_in_full() result
notes-merge: drop dead zero-write code
files-backend: prefer "0" for write_in_full() error check
Some commands (most notably "git status") makes an opportunistic
update when performing a read-only operation to help optimize later
operations in the same repository. The new "--no-optional-locks"
option can be passed to Git to disable them.
* jk/no-optional-locks:
git: add --no-optional-locks option
Add comment to a few functions that use a short-lived buffer the
caller can peek and copy out of.
* hn/path-ownership-comment:
read_gitfile_gently: clarify return value ownership.
real_path: clarify return value ownership
"git branch" learned "-c/-C" to create a new branch by copying an
existing one.
* sd/branch-copy:
branch: fix "copy" to never touch HEAD
branch: add a --copy (-c) option to go with --move (-m)
branch: add test for -m renaming multiple config sections
config: create a function to format section headers
Recent versions of "git rev-parse --parseopt" did not parse the
option specification that does not have the optional flags (*=?!)
correctly, which has been corrected.
* bc/rev-parse-parseopt-fix:
parse-options: only insert newline in help text if needed
parse-options: write blank line to correct output stream
t0040,t1502: Demonstrate parse_options bugs
git-rebase: don't ignore unexpected command line arguments
rev-parse parseopt: interpret any whitespace as start of help text
rev-parse parseopt: do not search help text for flag chars
t1502: demonstrate rev-parse --parseopt option mis-parsing
The final batch to "git rebase -i" updates to move more code from
the shell script to C.
* js/rebase-i-final:
rebase -i: rearrange fixup/squash lines using the rebase--helper
t3415: test fixup with wrapped oneline
rebase -i: skip unnecessary picks using the rebase--helper
rebase -i: check for missing commits in the rebase--helper
t3404: relax rebase.missingCommitsCheck tests
rebase -i: also expand/collapse the SHA-1s via the rebase--helper
rebase -i: do not invent onelines when expanding/collapsing SHA-1s
rebase -i: remove useless indentation
rebase -i: generate the script via rebase--helper
t3415: verify that an empty instructionFormat is handled as before
Memory leaks in various codepaths have been plugged.
* ma/leakplugs:
pack-bitmap[-write]: use `object_array_clear()`, don't leak
object_array: add and use `object_array_pop()`
object_array: use `object_array_clear()`, not `free()`
leak_pending: use `object_array_clear()`, not `free()`
commit: fix memory leak in `reduce_heads()`
builtin/commit: fix memory leak in `prepare_index()`
As "git commit" to conclude a conflicted "git merge" honors the
commit-msg hook, "git merge" that records a merge commit that
cleanly auto-merges should, but it didn't.
* sb/merge-commit-msg-hook (2017-09-22) 1 commit
(merged to 'next' on 2017-09-25 at 096e0502a8)
+ Documentation/githooks: mention merge in commit-msg hook
Add documentation for a topic that has recently graduated to the
'master' branch.
* sb/merge-commit-msg-hook:
Documentation/githooks: mention merge in commit-msg hook
"git fast-export" with -M/-C option issued "copy" instruction on a
path that is simultaneously modified, which was incorrect.
* jt/fast-export-copy-modify-fix:
fast-export: do not copy from modified file
"git describe --match <pattern>" has been taught to play well with
the "--all" option.
* mk/describe-match-with-all:
describe: teach --match to handle branches and remotes
"git status --ignored", when noticing that a directory without any
tracked path is ignored, still enumerated all the ignored paths in
the directory, which is unnecessary. The codepath has been
optimized to avoid this overhead.
* jm/status-ignored-directory-optim:
Improve performance of git status --ignored
Leaving spaces around the `-delimeters for commands means asciidoc fails
to parse them as the start of a literal string. Remove an extraneous
space that is causing a literal to not be formatted as such.
Signed-off-by: Adam Dinwoodie <adam@dinwoodie.org>
Acked-by: Andreas Heiduk <asheiduk@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation for '-X<option>' for merges was misleadingly
written to suggest that "-s theirs" exists, which is not the case.
* jc/merge-x-theirs-docfix:
merge-strategies: avoid implying that "-s theirs" exists
The delta format used in the packfile cannot reference data at
offset larger than what can be expressed in 4-byte, but the
generator for the data failed to make sure the offset does not
overflow. This has been corrected.
* mk/diff-delta-avoid-large-offset:
diff-delta: do not allow delta offset truncation
The machinery to create xdelta used in pack files received the
sizes of the data in size_t, but lost the higher bits of them by
storing them in "unsigned int" during the computation, which is
fixed.
* mk/diff-delta-uint-may-be-shorter-than-ulong:
diff-delta: fix encoding size that would not fit in "unsigned int"
Code clean-up.
* rs/resolve-ref-optional-result:
refs: pass NULL to resolve_ref_unsafe() if hash is not needed
refs: pass NULL to refs_resolve_ref_unsafe() if hash is not needed
refs: make sha1 output parameter of refs_resolve_ref_unsafe() optional
"git mailinfo" was loose in decoding quoted printable and produced
garbage when the two letters after the equal sign are not
hexadecimal. This has been fixed.
* rs/mailinfo-qp-decode-fix:
mailinfo: don't decode invalid =XY quoted-printable sequences
The built-in pattern to detect the "function header" for HTML did
not match <H1>..<H6> elements without any attributes, which has
been fixed.
* ik/userdiff-html-h-element-fix:
userdiff: fix HTML hunk header regexp
Many codepaths have been updated to squelch -Wimplicit-fallthrough
warnings from Gcc 7 (which is a good code hygiene).
* jk/fallthrough:
consistently use "fallthrough" comments in switches
curl_trace(): eliminate switch fallthrough
test-line-buffer: simplify command parsing
"git filter-branch" cannot reproduce a history with a tag without
the tagger field, which only ancient versions of Git allowed to be
created. This has been corrected.
* ic/fix-filter-branch-to-handle-tag-without-tagger:
filter-branch: use hash-object instead of mktag
filter-branch: stash away ref map in a branch
filter-branch: preserve and restore $GIT_AUTHOR_* and $GIT_COMMITTER_*
filter-branch: reset $GIT_* before cleaning up
"git describe --match" learned to take multiple patterns in v2.13
series, but the feature ignored the patterns after the first one
and did not work at all. This has been fixed.
* jk/describe-omit-some-refs:
describe: fix matching to actually match all patterns
When a submodule diff should be displayed we currently just add the
submodule objects to the main object store and then e.g. walk the
revision graph and create a summary for that submodule.
It is possible that we are missing the submodule either completely or
partially, which we currently differentiate with different error messages
depending on whether (1) the whole submodule object store is missing or
(2) just the needed for this particular diff. (1) is reported as
"not initialized", and (2) is reported as "commits not present".
If a submodule is deinit'ed its repository data is still around inside
the superproject, such that the diff can still be produced. In that way
the error message (1) is misleading as we can have a diff despite the
submodule being not initialized.
Downgrade the error message (1) to be the same as (2) and just say
the commits are not present, as that is the true reason why the diff
cannot be shown.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 146fdb0dfe (diff.c: emit_diff_symbol learns about DIFF_SYMBOL_SUMMARY,
2017-06-29), the conversion from direct printing to the symbol emission
dropped the new line character for renamed, copied and rewritten files.
Add the emission of a newline, add a test for this case.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some tools like IDEs or fancy editors may periodically run
commands like "git status" in the background to keep track
of the state of the repository. Some of these commands may
refresh the index and write out the result in an
opportunistic way: if they can get the index lock, then they
update the on-disk index with any updates they find. And if
not, then their in-core refresh is lost and just has to be
recomputed by the next caller.
But taking the index lock may conflict with other operations
in the repository. Especially ones that the user is doing
themselves, which _aren't_ opportunistic. In other words,
"git status" knows how to back off when somebody else is
holding the lock, but other commands don't know that status
would be happy to drop the lock if somebody else wanted it.
There are a couple possible solutions:
1. Have some kind of "pseudo-lock" that allows other
commands to tell status that they want the lock.
This is likely to be complicated and error-prone to
implement (and maybe even impossible with just
dotlocks to work from, as it requires some
inter-process communication).
2. Avoid background runs of commands like "git status"
that want to do opportunistic updates, preferring
instead plumbing like diff-files, etc.
This is awkward for a couple of reasons. One is that
"status --porcelain" reports a lot more about the
repository state than is available from individual
plumbing commands. And two is that we actually _do_
want to see the refreshed index. We just don't want to
take a lock or write out the result. Whereas commands
like diff-files expect us to refresh the index
separately and write it to disk so that they can depend
on the result. But that write is exactly what we're
trying to avoid.
3. Ask "status" not to lock or write the index.
This is easy to implement. The big downside is that any
work done in refreshing the index for such a call is
lost when the process exits. So a background process
may end up re-hashing a changed file multiple times
until the user runs a command that does an index
refresh themselves.
This patch implements the option 3. The idea (and the test)
is largely stolen from a Git for Windows patch by Johannes
Schindelin, 67e5ce7f63 (status: offer *not* to lock the
index and update it, 2016-08-12). The twist here is that
instead of making this an option to "git status", it becomes
a "git" option and matching environment variable.
The reason there is two-fold:
1. An environment variable is carried through to
sub-processes. And whether an invocation is a
background process or not should apply to the whole
process tree. So you could do "git --no-optional-locks
foo", and if "foo" is a script or alias that calls
"status", you'll still get the effect.
2. There may be other programs that want the same
treatment.
I've punted here on finding more callers to convert,
since "status" is the obvious one to call as a repeated
background job. But "git diff"'s opportunistic refresh
of the index may be a good candidate.
The test is taken from 67e5ce7f63, and it's worth repeating
Johannes's explanation:
Note that the regression test added in this commit does
not *really* verify that no index.lock file was written;
that test is not possible in a portable way. Instead, we
verify that .git/index is rewritten *only* when `git
status` is run without `--no-optional-locks`.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a candidate HEAD isn't a symref, we check that it
contains a viable sha1. But in a post-sha1 world, we should
be checking whether it has any plausible object-id.
We can do that by switching to get_oid_hex().
Note that both before and after this patch, we only check
for a plausible object id at the start of the file, and then
call that good enough. We ignore any content _after_ the
hex, so a string like:
0123456789012345678901234567890123456789 foo
is accepted. Though we do put extra bytes like this into
some pseudorefs (e.g., FETCH_HEAD), we don't typically do so
with HEAD. We could tighten this up by using parse_oid_hex(),
like:
if (!parse_oid_hex(buffer, &oid, &end) &&
*end++ == '\n' && *end == '\0')
return 0;
But we're probably better to remain on the loose side. We're
just checking here for a plausible-looking repository
directory, so heuristics are acceptable (if we really want
to be meticulous, we should use the actual ref code to parse
HEAD).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the previous commit guarantees that our symref buffer
is NUL-terminated, we can just use skip_prefix() and friends
to parse it. This is shorter and saves us having to deal
with magic numbers and keeping the "len" counter up to date.
While we're at it, let's name the rather obscure "buf" to
"refname", since that is the thing we are parsing with it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are checking to see if we have a git repo, we peek
into the HEAD file and see if it's a plausible symlink,
symref, or detached HEAD.
For the latter two, we read the contents with read_in_full(),
which means they aren't NUL-terminated. The symref check is
careful to respect the length we got, but the sha1 check
will happily parse up to 40 bytes, even if we read fewer.
E.g.,:
echo 1234 >.git/HEAD
git rev-parse
will parse 36 uninitialized bytes from our stack buffer.
This isn't a big deal in practice. Our buffer is 256 bytes,
so we know we'll never read outside of it. The worst case is
that the uninitialized bytes look like valid hex, and we
claim a bogus HEAD file is valid. The chances of this
happening randomly are quite slim, but let's be careful.
One option would be to check that "len == 41" before feeding
the buffer to get_sha1_hex(). But we'd like to eventually
prepare for a world with variable-length hashes. Let's
NUL-terminate as soon as we've read the buffer (we already
even leave a spare byte to do so!). That fixes this problem
without depending on the size of an object id.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We try to read "len" bytes into a buffer and just assume
that it happened correctly. In practice this should usually
be the case, since we just stat'd the file to get the
length. But we could be fooled by transient errors or by
other processes racily truncating the file.
Let's be more careful. There's a slim chance this could
catch a real error, but it also prevents people and tools
from getting worried while reading the code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To read the "gitdir" file into memory, we stat the file and
allocate a buffer. But we store the size in an "int", which
may be truncated. We should use a size_t and xsize_t(),
which will detect truncation.
An overflow is unlikely for a "gitdir" file, but it's a good
practice to model.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many callers of read_in_full() expect to see the exact
number of bytes requested, but their error handling lumps
together true read errors and short reads due to unexpected
EOF.
We can give more specific error messages by separating these
cases (showing errno when appropriate, and otherwise
describing the short read).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a caller tries to read a particular set of bytes via
read_in_full(), there are three possible outcomes:
1. An error, in which case -1 is returned and errno is
set.
2. A short read, in which fewer bytes are returned and
errno is unspecified (we never saw a read error, so we
may have some random value from whatever syscall failed
last).
3. The full read completed successfully.
Many callers handle cases 1 and 2 together by just checking
the result against the requested size. If their combined
error path looks at errno (e.g., by calling die_errno), they
may report a nonsense value.
Let's fix these sites by having them distinguish between the
two error cases. That avoids the random errno confusion, and
lets us give more detailed error messages.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Comparing the result of read_in_full() using less-than is
potentially dangerous, as a negative return value may be
converted to an unsigned type and be considered a success.
This is discussed further in 561598cfcf (read_pack_header:
handle signed/unsigned comparison in read result,
2017-09-13).
Each of these instances is actually fine in practice:
- in get-tar-commit-id, the HEADERSIZE macro expands to a
signed integer. If it were switched to an unsigned type
(e.g., a size_t), then it would be a bug.
- the other two callers check for a short read only after
handling a negative return separately. This is a fine
practice, but we'd prefer to model "!=" as a general
rule.
So all of these cases can be considered cleanups and not
actual bugfixes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
