A common mistake when writing binary search is to allow possible
integer overflow by using the simple average:
mid = (min + max) / 2;
Instead, use the overflow-safe version:
mid = min + (max - min) / 2;
This translation is safe since the operation occurs inside a loop
conditioned on "min < max". The included changes were found using
the following git grep:
git grep '/ *2;' '*.c'
Making this cleanup will prevent future review friction when a new
binary search is contructed based on existing code.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix regression of "git add -p" for users with "color.ui = always"
in their configuration, by merging the topic below and adjusting it
for the 'master' front.
* jk/ui-color-always-to-auto:
t7301: use test_terminal to check color
t4015: use --color with --color-moved
color: make "always" the same as "auto" in config
provide --color option for all ref-filter users
t3205: use --color instead of color.branch=always
t3203: drop "always" color test
t6006: drop "always" color config tests
t7502: use diff.noprefix for --verbose test
t7508: use test_terminal for color output
t3701: use test-terminal to collect color output
t4015: prefer --color to -c color.diff=always
test-terminal: set TERM=vt100
Many variables that points at a region of memory that will live
throughout the life of the program have been marked with UNLEAK
marker to help the leak checkers concentrate on real leaks..
* ma/builtin-unleak:
builtin/: add UNLEAKs
Code clean-up.
* rs/cleanup-strbuf-users:
graph: use strbuf_addchars() to add spaces
use strbuf_addstr() for adding strings to strbufs
path: use strbuf_add_real_path()
Code clean-up.
* rs/resolve-ref-optional-result:
refs: pass NULL to resolve_refdup() if hash is not needed
refs: pass NULL to refs_resolve_refdup() if hash is not needed
Our documentation advises to not re-use a strbuf, after strbuf_release
has been called on it. Use the proper reset instead.
Currently 'strbuf_release' releases and re-initializes the strbuf, so it
is safe, but slow. 'strbuf_reset' only resets the internal length variable,
such that this could also be accounted for as a micro-optimization.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The error messages shown when the branch command is misused
by supplying it wrong number of parameters wasn't meaningful.
That's because it used the the phrase "too many branches"
assuming all parameters to be "valid" branch names. It's not
always the case as exemplified below,
$ git branch
foo
* master
$ git branch -m foo foo old
fatal: too many branches for a rename operation
Change the messages to be more general thus making no assumptions
about the "parameters".
Signed-off-by: Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/ui-color-always-to-auto-maint:
color: make "always" the same as "auto" in config
provide --color option for all ref-filter users
t3205: use --color instead of color.branch=always
t3203: drop "always" color test
t6006: drop "always" color config tests
t7502: use diff.noprefix for --verbose test
t7508: use test_terminal for color output
t3701: use test-terminal to collect color output
t4015: prefer --color to -c color.diff=always
test-terminal: set TERM=vt100
When ref-filter learned about want_color() in 11b087adfd
(ref-filter: consult want_color() before emitting colors,
2017-07-13), it became useful to be able to turn colors off
and on for specific commands. For git-branch, you can do so
with --color/--no-color.
But for git-for-each-ref and git-tag, the other users of
ref-filter, you have no option except to tweak the
"color.ui" config setting. Let's give both of these commands
the usual color command-line options.
This is a bit more obvious as a method for overriding the
config. And it also prepares us for the behavior of "always"
changing (so that we are still left with a way of forcing
color when our output goes to a non-terminal).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
"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
Use strbuf_addstr() instead of strbuf_addf() for adding strings. That's
simpler and makes the intent clearer.
Patch generated by Coccinelle and contrib/coccinelle/strbuf.cocci;
adjusted indentation in refs/packed-backend.c manually.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add some UNLEAKs where we are about to return from `cmd_*`. UNLEAK the
variables in the same order as we've declared them. While addressing
`msg` in builtin/tag.c, convert the existing `strbuf_release()` calls as
well.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to get rid of several write-only variables.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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()`
"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
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
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 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
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>
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>
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>
"git rev-parse" learned "--is-shallow-repository", that is to be
used in a way similar to existing "--is-bare-repository" and
friends.
* ow/rev-parse-is-shallow-repo:
rev-parse: rev-parse: add --is-shallow-repository
"git gc" tries to avoid running two instances at the same time by
reading and writing pid/host from and to a lock file; it used to
use an incorrect fscanf() format when reading, which has been
corrected.
* aw/gc-lockfile-fscanf-fix:
gc: call fscanf() with %<len>s, not %<len>c, when reading hostname
Step #0 of a planned & larger series to make the in-core object
store per in-core repository object.
* jn/per-repo-object-store-fixes:
replace-objects: evaluate replacement refs without using the object store
push, fetch: error out for submodule entries not pointing to commits
pack: make packed_git_mru global a value instead of a pointer
Many codepaths did not diagnose write failures correctly when disks
go full, due to their misuse of write_in_full() helper function,
which have been corrected.
* jk/write-in-full-fix:
read_pack_header: handle signed/unsigned comparison in read result
config: flip return value of store_write_*()
notes-merge: use ssize_t for write_in_full() return value
pkt-line: check write_in_full() errors against "< 0"
convert less-trivial versions of "write_in_full() != len"
avoid "write_in_full(fd, buf, len) != len" pattern
get-tar-commit-id: check write_in_full() return against 0
config: avoid "write_in_full(fd, buf, len) < len" pattern
This allows us to get rid of some write-only variables, among them seven
SHA1 buffers.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a couple of places, we pop objects off an object array `foo` by
decreasing `foo.nr`. We access `foo.nr` in many places, but most if not
all other times we do so read-only, e.g., as we iterate over the array.
But when we change `foo.nr` behind the array's back, it feels a bit
nasty and looks like it might leak memory.
Leaks happen if the popped element has an allocated `name` or `path`.
At the moment, that is not the case. Still, 1) the object array might
gain more fields that want to be freed, 2) a code path where we pop
might start using names or paths, 3) one of these code paths might be
copied to somewhere where we do, and 4) using a dedicated function for
popping is conceptually cleaner.
Introduce and use `object_array_pop()` instead. Release memory in the
new function. Document that popping an object leaves the associated
elements in limbo.
The converted places were identified by grepping for "\.nr\>" and
looking for "--".
Make the new function return NULL on an empty array. This is consistent
with `pop_commit()` and allows the following:
while ((o = object_array_pop(&foo)) != NULL) {
// do something
}
But as noted above, we don't need to go out of our way to avoid reading
`foo.nr`. This is probably more readable:
while (foo.nr) {
... o = object_array_pop(&foo);
// do something
}
The name of `object_array_pop()` does not quite align with
`add_object_array()`. That is unfortunate. On the other hand, it matches
`object_array_clear()`. Arguably it's `add_...` that is the odd one out,
since it reads like it's used to "add" an "object array". For that
reason, side with `object_array_clear()`.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of freeing `foo.objects` for an object array `foo` (sometimes
conditionally), call `object_array_clear(&foo)`. This means we don't
poke as much into the implementation, which is already a good thing, but
also that we release the individual entries as well, thereby fixing at
least one memory-leak (in diff-lib.c).
If someone is holding on to a pointer to an element's `name` or `path`,
that is now a dangling pointer, i.e., we'd be turning an unpleasant
situation into an outright bug. To the best of my understanding no such
long-term pointers are being taken.
The way we handle `study` in builting/reflog.c still looks like it might
leak. That will be addressed in the next commit.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Setting `leak_pending = 1` tells `prepare_revision_walk()` not to
release the `pending` array, and makes that the caller's responsibility.
See 4a43d374f (revision: add leak_pending flag, 2011-10-01) and
353f5657a (bisect: use leak_pending flag, 2011-10-01).
Commit 1da1e07c8 (clean up name allocation in prepare_revision_walk,
2014-10-15) fixed a memory leak in `prepare_revision_walk()` by
switching from `free()` to `object_array_clear()`. However, where we use
the `leak_pending`-mechanism, we're still only calling `free()`.
Use `object_array_clear()` instead. Copy some helpful comments from
353f5657a to the other callers that we update to clarify the memory
responsibilities, and to highlight that the commits are not affected
when we clear the array -- it is indeed correct to both tidy up the
commit flags and clear the object array.
Document `leak_pending` in revision.h to help future users get this
right.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Release `pathspec` and the string list `partial`.
When we clear the string list, make sure we do not free the `util`
pointers. That would result in double-freeing, since we set them up as
`item->util = item` in `list_paths()`.
Initialize the string list early, so that we can always release it. That
introduces some unnecessary overhead in various code paths, but means
there is one and only one way out of the function. If we ever accumulate
more things we need to free, it should be straightforward to do so.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a new branch B by copying the branch A that happens to
be the current branch, it also updates HEAD to point at the new
branch. It probably was made this way because "git branch -c A B"
piggybacked its implementation on "git branch -m A B",
This does not match the usual expectation. If I were sitting on a
blue chair, and somebody comes and repaints it to red, I would
accept ending up sitting on a chair that is now red (I am also OK to
stand, instead, as there no longer is my favourite blue chair). But
if somebody creates a new red chair, modelling it after the blue
chair I am sitting on, I do not expect to be booted off of the blue
chair and ending up on sitting on the new red one.
Let's fix this before it hits 'next'. Those who want to create a
new branch and switch to it can do "git checkout B" after doing a
"git branch -c B", and if that operation is so useful and deserves a
short-hand way to do so, perhaps extend "git checkout -b B" to copy
configurations while creating the new branch B.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Gcc 7 adds -Wimplicit-fallthrough, which can warn when a
switch case falls through to the next case. The general idea
is that the compiler can't tell if this was intentional or
not, so you should annotate any intentional fall-throughs as
such, leaving it to complain about any unannotated ones.
There's a GNU __attribute__ which can be used for
annotation, but of course we'd have to #ifdef it away on
non-gcc compilers. Gcc will also recognize
specially-formatted comments, which matches our current
practice. Let's extend that practice to all of the
unannotated sites (which I did look over and verify that
they were behaving as intended).
Ideally in each case we'd actually give some reasons in the
comment about why we're falling through, or what we're
falling through to. And gcc does support that with
-Wimplicit-fallthrough=2, which relaxes the comment pattern
matching to anything that contains "fallthrough" (or a
variety of spelling variants). However, this isn't the
default for -Wimplicit-fallthrough, nor for -Wextra. In the
name of simplicity, it's probably better for us to support
the default level, which requires "fallthrough" to be the
only thing in the comment (modulo some window dressing like
"else" and some punctuation; see the gcc manual for the
complete set of patterns).
This patch suppresses all warnings due to
-Wimplicit-fallthrough. We might eventually want to add that
to the DEVELOPER Makefile knob, but we should probably wait
until gcc 7 is more widely adopted (since earlier versions
will complain about the unknown warning type).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit dc944b65f1 (get_sha1_with_context: dynamically
allocate oc->path, 2017-05-19) changed the rules that
callers must follow for seeing if we parsed a path in the
object name. The rules switched from "check if the oc.path
buffer is empty" to "check if the oc.path pointer is NULL".
But that commit forgot to update some sites in
cat_one_file(), meaning we might dereference a NULL pointer.
You can see this by making a path-aware request like
--textconv without specifying --path, and giving an object
name that doesn't have a path in it. Like:
git cat-file --textconv HEAD
which will reliably segfault.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When run with the "-C" option, fast-export writes 'C' commands in its
output whenever the internal diff mechanism detects a file copy,
indicating that fast-import should copy the given existing file to the
given new filename. However, the diff mechanism works against the
prior version of the file, whereas fast-import uses whatever is current.
This causes issues when a commit both modifies a file and uses it as the
source for a copy.
Therefore, teach fast-export to refrain from writing 'C' when it has
already written a modification command for a file.
An existing test in t9350-fast-export is also fixed in this patch. The
existing line "C file6 file7" copies the wrong version of file6, but it
has coincidentally worked because file7 was subsequently overridden.
Reported-by: Juraj Oršulić <juraj.orsulic@fer.hr>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When `git describe` uses `--match`, it matches only tags, basically
ignoring the `--all` argument even when it is specified.
Fix it by also matching branch name and $remote_name/$remote_branch_name,
for remote-tracking references, with the specified patterns. Update
documentation accordingly and add tests.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
