Commit graph

7491 commits

Author SHA1 Message Date
Nguyễn Thái Ngọc Duy 7fdff47432 refs.c: remove the_repo from read_ref_at()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:33 +09:00
SZEDER Gábor d2c4e6292a builtin rebase: use oideq()
Use oideq() instead of !oidcmp(), as it is more idiomatic, and might
give the compiler more opportunities to optimize.

Patch generated with 'contrib/coccinelle/free.cocci' and Coccinelle
v1.0.7 (previous Coccinelle versions don't notice this).

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:32 +09:00
SZEDER Gábor 7762f44ee0 builtin rebase: use FREE_AND_NULL
Use the macro FREE_AND_NULL to release memory allocated for
'head_name' and clear its pointer.

Patch generated with 'contrib/coccinelle/free.cocci' and Coccinelle
v1.0.7 (previous Coccinelle versions don't notice this).

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-08 17:26:32 +09:00
Junio C Hamano 0c45fa32ec Merge branch 'br/commit-tree-parseopt'
The command line parser of "git commit-tree" has been rewritten to
use the parse-options API.

* br/commit-tree-parseopt:
  commit-tree: utilize parse-options api
2019-03-20 15:16:08 +09:00
Junio C Hamano 6b5688b760 Merge branch 'ma/clear-repository-format'
The setup code has been cleaned up to avoid leaks around the
repository_format structure.

* ma/clear-repository-format:
  setup: fix memory leaks with `struct repository_format`
  setup: free old value before setting `work_tree`
2019-03-20 15:16:07 +09:00
Junio C Hamano 83b13e284c Merge branch 'jk/virtual-objects-do-exist'
A recent update broke "is this object available to us?" check for
well-known objects like an empty tree (which should yield "yes",
even when there is no on-disk object for an empty tree), which has
been corrected.

* jk/virtual-objects-do-exist:
  rev-list: allow cached objects in existence check
2019-03-20 15:16:07 +09:00
Junio C Hamano 27cdbdd134 Merge branch 'jk/no-sigpipe-during-network-transport'
On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX),
the upload-pack that runs on the other end that hangs up after
detecting an error could cause "git fetch" to die with a signal,
which led to a flakey test.  "git fetch" now ignores SIGPIPE during
the network portion of its operation (this is not a problem as we
check the return status from our write(2)s).

* jk/no-sigpipe-during-network-transport:
  fetch: ignore SIGPIPE during network operation
  fetch: avoid calling write_or_die()
2019-03-20 15:16:06 +09:00
Junio C Hamano ea327760d3 Merge branch 'jk/fsck-doc'
"git fsck --connectivity-only" omits computation necessary to sift
the objects that are not reachable from any of the refs into
unreachable and dangling.  This is now enabled when dangling
objects are requested (which is done by default, but can be
overridden with the "--no-dangling" option).

* jk/fsck-doc:
  fsck: always compute USED flags for unreachable objects
  doc/fsck: clarify --connectivity-only behavior
2019-03-20 15:16:06 +09:00
Junio C Hamano 9fbcc3d203 Merge branch 'js/rebase-orig-head-fix'
"git rebase" that was reimplemented in C did not set ORIG_HEAD
correctly, which has been corrected.

* js/rebase-orig-head-fix:
  built-in rebase: set ORIG_HEAD just once, before the rebase
  built-in rebase: demonstrate that ORIG_HEAD is not set correctly
  built-in rebase: use the correct reflog when switching branches
  built-in rebase: no need to check out `onto` twice
2019-03-20 15:16:05 +09:00
Brandon Richardson cbdeab98e8 commit-tree: utilize parse-options api
Rather than parse options manually, which is both difficult to
read and error prone, parse options supplied to commit-tree
using the parse-options api.

It was discovered that the --no-gpg-sign option was documented
but not implemented in commit 70ddbd7767 (commit-tree: add missing
--gpg-sign flag, 2019-01-19), and the existing implementation
would attempt to translate the option as a tree oid. It was also
suggested earlier in commit 55ca3f99ae (commit-tree: add and document
--no-gpg-sign, 2013-12-13) that commit-tree should be migrated to
utilize the parse-options api, which could help prevent mistakes
like this in the future. Hence this change.

Also update the documentation to better describe that mixing
`-m` and `-F` options will correctly compose commit log messages in the
order in which the options are given.

In the process, mark various strings for translation.

Signed-off-by: Brandon Richardson <brandon1024.br@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-08 10:31:24 +09:00
Junio C Hamano 12e5bdd9c4 Merge branch 'jk/diff-no-index-initialize'
"git diff --no-index" may still want to access Git goodies like
--ext-diff and --textconv, but so far these have been ignored,
which has been corrected.

* jk/diff-no-index-initialize:
  diff: reuse diff setup for --no-index case
2019-03-07 09:59:59 +09:00
Junio C Hamano b0e7fb2e5c Merge branch 'nd/completion-more-parameters'
The command line completion (in contrib/) has been taught to
complete more subcommand parameters.

* nd/completion-more-parameters:
  completion: add more parameter value completion
2019-03-07 09:59:58 +09:00
Junio C Hamano 4751a1673c Merge branch 'ab/receive-pack-use-after-free-fix'
Memfix.

* ab/receive-pack-use-after-free-fix:
  receive-pack: fix use-after-free bug
2019-03-07 09:59:57 +09:00
Junio C Hamano f7213a3d33 Merge branch 'jk/prune-optim'
"git prune" has been taught to take advantage of reachability
bitmap when able.

* jk/prune-optim:
  t5304: rename "sha1" variables to "oid"
  prune: check SEEN flag for reachability
  prune: use bitmaps for reachability traversal
  prune: lazily perform reachability traversal
2019-03-07 09:59:56 +09:00
Junio C Hamano 32038fef00 Merge branch 'jh/trace2'
A more structured way to obtain execution trace has been added.

* jh/trace2:
  trace2: add for_each macros to clang-format
  trace2: t/helper/test-trace2, t0210.sh, t0211.sh, t0212.sh
  trace2:data: add subverb for rebase
  trace2:data: add subverb to reset command
  trace2:data: add subverb to checkout command
  trace2:data: pack-objects: add trace2 regions
  trace2:data: add trace2 instrumentation to index read/write
  trace2:data: add trace2 hook classification
  trace2:data: add trace2 transport child classification
  trace2:data: add trace2 sub-process classification
  trace2:data: add editor/pager child classification
  trace2:data: add trace2 regions to wt-status
  trace2: collect Windows-specific process information
  trace2: create new combined trace facility
  trace2: Documentation/technical/api-trace2.txt
2019-03-07 09:59:56 +09:00
Junio C Hamano ebf846c008 Merge branch 'rj/prune-packed-excess-args'
"git prune-packed" did not notice and complain against excess
arguments given from the command line, which now it does.

* rj/prune-packed-excess-args:
  prune-packed: check for too many arguments
2019-03-07 09:59:55 +09:00
Junio C Hamano c425d361f5 Merge branch 'en/combined-all-paths'
Output from "diff --cc" did not show the original paths when the
merge involved renames.  A new option adds the paths in the
original trees to the output.

* en/combined-all-paths:
  log,diff-tree: add --combined-all-paths option
2019-03-07 09:59:54 +09:00
Junio C Hamano cf0879f7e9 Merge branch 'sc/pack-redundant'
Update the implementation of pack-redundant for performance in a
repository with many packfiles.

* sc/pack-redundant:
  pack-redundant: consistent sort method
  pack-redundant: rename pack_list.all_objects
  pack-redundant: new algorithm to find min packs
  pack-redundant: delete redundant code
  pack-redundant: delay creation of unique_objects
  t5323: test cases for git-pack-redundant
2019-03-07 09:59:54 +09:00
Junio C Hamano 3710f60a80 Merge branch 'du/branch-show-current'
"git branch" learned a new subcommand "--show-current".

* du/branch-show-current:
  branch: introduce --show-current display option
2019-03-07 09:59:54 +09:00
Junio C Hamano 4e021dc28e Merge branch 'wh/author-committer-ident-config'
Four new configuration variables {author,committer}.{name,email}
have been introduced to override user.{name,email} in more specific
cases.

* wh/author-committer-ident-config:
  config: allow giving separate author and committer idents
2019-03-07 09:59:53 +09:00
Junio C Hamano 54b469b9e9 Merge branch 'nd/diff-parseopt'
The diff machinery, one of the oldest parts of the system, which
long predates the parse-options API, uses fairly long and complex
handcrafted option parser.  This is being rewritten to use the
parse-options API.

* nd/diff-parseopt:
  diff.c: convert --raw
  diff.c: convert -W|--[no-]function-context
  diff.c: convert -U|--unified
  diff.c: convert -u|-p|--patch
  diff.c: prepare to use parse_options() for parsing
  diff.h: avoid bit fields in struct diff_flags
  diff.h: keep forward struct declarations sorted
  parse-options: allow ll_callback with OPTION_CALLBACK
  parse-options: avoid magic return codes
  parse-options: stop abusing 'callback' for lowlevel callbacks
  parse-options: add OPT_BITOP()
  parse-options: disable option abbreviation with PARSE_OPT_KEEP_UNKNOWN
  parse-options: add one-shot mode
  parse-options.h: remove extern on function prototypes
2019-03-07 09:59:52 +09:00
Junio C Hamano 7d0c1f4556 Merge branch 'tg/checkout-no-overlay'
"git checkout --no-overlay" can be used to trigger a new mode of
checking out paths out of the tree-ish, that allows paths that
match the pathspec that are in the current index and working tree
and are not in the tree-ish.

* tg/checkout-no-overlay:
  revert "checkout: introduce checkout.overlayMode config"
  checkout: introduce checkout.overlayMode config
  checkout: introduce --{,no-}overlay option
  checkout: factor out mark_cache_entry_for_checkout function
  checkout: clarify comment
  read-cache: add invalidate parameter to remove_marked_cache_entries
  entry: support CE_WT_REMOVE flag in checkout_entry
  entry: factor out unlink_entry function
  move worktree tests to t24*
2019-03-07 09:59:51 +09:00
Jeff King 8d8c2a5aef fsck: always compute USED flags for unreachable objects
The --connectivity-only option avoids opening every object, and instead
just marks reachable objects with a flag and compares this to the set
of all objects. This strategy is discussed in more detail in 3e3f8bd608
(fsck: prepare dummy objects for --connectivity-check, 2017-01-17).

This means that we report _every_ unreachable object as dangling.
Whereas in a full fsck, we'd have actually opened and parsed each of
those unreachable objects, marking their child objects with the USED
flag, to mean "this was mentioned by another object". And thus we can
report only the tip of an unreachable segment of the object graph as
dangling.

You can see this difference with a trivial example:

  tree=$(git hash-object -t tree -w /dev/null)
  one=$(echo one | git commit-tree $tree)
  two=$(echo two | git commit-tree -p $one $tree)

Running `git fsck` will report only $two as dangling, but with
--connectivity-only, both commits (and the tree) are reported. Likewise,
using --lost-found would write all three objects.

We can make --connectivity-only work like the normal case by taking a
separate pass over the unreachable objects, parsing them and marking
objects they refer to as USED. That still avoids parsing any blobs,
though we do pay the cost to access any unreachable commits and trees
(which may or may not be noticeable, depending on how many you have).

If neither --dangling nor --lost-found is in effect, then we can skip
this step entirely, just like we do now. That makes "--connectivity-only
--no-dangling" just as fast as the current "--connectivity-only". I.e.,
we do the correct thing always, but you can still tweak the options to
make it faster if you don't care about dangling objects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-05 22:55:57 +09:00
Jeff King f06ab027ef rev-list: allow cached objects in existence check
This fixes a regression in 7c0fe330d5 (rev-list: handle missing tree
objects properly, 2018-10-05) where rev-list will now complain about the
empty tree when it doesn't physically exist on disk.

Before that commit, we relied on the traversal code in list-objects.c to
walk through the trees. Since it uses parse_tree(), we'd do a normal
object lookup that includes looking in the set of "cached" objects
(which is where our magic internal empty-tree kicks in).

After that commit, we instead tell list-objects.c not to die on any
missing trees, and we check them ourselves using has_object_file(). But
that function uses OBJECT_INFO_SKIP_CACHED, which means we won't use our
internal empty tree.

This normally wouldn't come up. For most operations, Git will try to
write out the empty tree object as it would any other object. And
pack-objects in a push or fetch will send the empty tree (even if it's
virtual on the sending side). However, there are cases where this can
matter. One I found in the wild:

  1. The root tree of a commit became empty by deleting all files,
     without using an index. In this case it was done using libgit2's
     tree builder API, but as the included test shows, it can easily be
     done with regular git using hash-object.

     The resulting repo works OK, as we'd avoid walking over our own
     reachable commits for a connectivity check.

  2. Cloning with --reference pointing to the repository from (1) can
     trigger the problem, because we tell the other side we already have
     that commit (and hence the empty tree), but then walk over it
     during the connectivity check (where we complain about it missing).

Arguably the workflow in step (1) should be more careful about writing
the empty tree object if we're referencing it. But this workflow did
work prior to 7c0fe330d5, so let's restore it.

This patch makes the minimal fix, which is to swap out a direct call to
oid_object_info_extended(), minus the SKIP_CACHED flag, instead of
calling has_object_file(). This is all that has_object_file() is doing
under the hood. And there's little danger of unrelated fallout from
other unexpected "cached" objects, since there's only one call site that
ends such a cached object, and it's in git-blame.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-05 22:28:29 +09:00
Jeff King 143588949c fetch: ignore SIGPIPE during network operation
The default SIGPIPE behavior can be useful for a command that generates
a lot of output: if the receiver of our output goes away, we'll be
notified asynchronously to stop generating it (typically by killing the
program).

But for a command like fetch, which is primarily concerned with
receiving data and writing it to disk, an unexpected SIGPIPE can be
awkward. We're already checking the return value of all of our write()
calls, and dying due to the signal takes away our chance to gracefully
handle the error.

On Linux, we wouldn't generally see SIGPIPE at all during fetch. If the
other side of the network connection hangs up, we'll see ECONNRESET. But
on OS X, we get a SIGPIPE, and the process is killed. This causes t5570
to racily fail, as we sometimes die by signal (instead of the expected
die() call) when the server side hangs up.

Let's ignore SIGPIPE during the network portion of the fetch, which will
cause our write() to return EPIPE, giving us consistent behavior across
platforms.

This fixes the test flakiness, but note that it stops short of fixing
the larger problem. The server side hit a fatal error, sent us an "ERR"
packet, and then hung up. We notice the failure because we're trying to
write to a closed socket. But by dying immediately, we never actually
read the ERR packet and report its content to the user. This is a (racy)
problem on all platforms. So this patch lays the groundwork from which
that problem might be fixed consistently, but it doesn't actually fix
it.

Note the placement of the SIGPIPE handling. The absolute minimal change
would be to ignore SIGPIPE only when we're writing. But twiddling the
signal handler for each write call is inefficient and maintenance
burden. On the opposite end of the spectrum, we could simply declare
that fetch does not need SIGPIPE handling, since it doesn't generate a
lot of output, and we could just ignore it at the start of cmd_fetch().

This patch takes a middle ground. It ignores SIGPIPE during the network
operation (which is admittedly most of the program, since the actual
network operations are all done under the hood by the transport code).
So it's still pretty coarse.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-05 15:02:18 +09:00
Johannes Schindelin cbd29ead92 built-in rebase: set ORIG_HEAD just once, before the rebase
Technically, the scripted version set ORIG_HEAD only in two spots (which
really could have been one, because it called `git checkout $onto^0` to
start the rebase and also if it could take a shortcut, and in both cases
it called `git update-ref $orig_head`).

Practically, it *implicitly* reset ORIG_HEAD whenever `git reset --hard`
was called.

However, what we really want is that it is set exactly once, at the
beginning of the rebase.

So let's do that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-04 13:31:04 +09:00
Johannes Schindelin eaf81605b8 built-in rebase: use the correct reflog when switching branches
By mistake, we used the reflog intended for ORIG_HEAD.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-04 13:31:04 +09:00
Johannes Schindelin e6aac8177d built-in rebase: no need to check out onto twice
In the case that the rebase boils down to a fast-forward, the built-in
rebase reset the working tree twice: once to start the rebase at `onto`,
then realizing that the original (pre-rebase) HEAD was an ancestor and
we basically already fast-forwarded to the post-rebase HEAD,
`reset_head()` was called to update the original ref and to point HEAD
back to it.

That second `reset_head()` call does not need to touch the working tree,
though, as it does not change the actual tip commit (and therefore the
working tree should stay unchanged anyway): only the ref needs to be
updated (because the rebase detached the HEAD, and we want to go back to
the branch on which the rebase was started).

But that second `reset_head()` was called without the flag to leave the
working tree alone (the reason: when that call was introduced, that flag
was not yet even thought of). Let's avoid that unnecessary work by
passing that flag.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-04 13:31:03 +09:00
Martin Ågren e8805af1c3 setup: fix memory leaks with struct repository_format
After we set up a `struct repository_format`, it owns various pieces of
allocated memory. We then either use those members, because we decide we
want to use the "candidate" repository format, or we discard the
candidate / scratch space. In the first case, we transfer ownership of
the memory to a few global variables. In the latter case, we just
silently drop the struct and end up leaking memory.

Introduce an initialization macro `REPOSITORY_FORMAT_INIT` and a
function `clear_repository_format()`, to be used on each side of
`read_repository_format()`. To have a clear and simple memory ownership,
let all users of `struct repository_format` duplicate the strings that
they take from it, rather than stealing the pointers.

Call `clear_...()` at the start of `read_...()` instead of just zeroing
the struct, since we sometimes enter the function multiple times. Thus,
it is important to initialize the struct before calling `read_...()`, so
document that. It's also important because we might not even call
`read_...()` before we call `clear_...()`, see, e.g., builtin/init-db.c.

Teach `read_...()` to clear the struct on error, so that it is reset to
a safe state, and document this. (In `setup_git_directory_gently()`, we
look at `repo_fmt.hash_algo` even if `repo_fmt.version` is -1, which we
weren't actually supposed to do per the API. After this commit, that's
ok.)

We inherit the existing code's combining "error" and "no version found".
Both are signalled through `version == -1` and now both cause us to
clear any partial configuration we have picked up. For "extensions.*",
that's fine, since they require a positive version number. For
"core.bare" and "core.worktree", we're already verifying that we have a
non-negative version number before using them.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-01 08:52:00 +09:00
Jeff King 287ab28bfa diff: reuse diff setup for --no-index case
When "--no-index" is in effect (or implied by the arguments), git-diff
jumps early to a special code path to perform that diff. This means we
miss out on some settings like enabling --ext-diff and --textconv by
default.

Let's jump to the no-index path _after_ we've done more setup on
rev.diffopt. Since some of the options don't affect us (e.g., items
related to the index), let's re-order the setup into two blocks (see the
in-code comments).

Note that we also need to stop re-initializing the diffopt struct in
diff_no_index(). This should not be necessary, as it will already have
been initialized by cmd_diff() (and there are no other callers). That in
turn lets us drop the "repository" argument from diff_no_index (which
never made much sense, since the whole point is that you don't need a
repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-24 07:08:34 -08:00
Jeff Hostetler b3a5d5a80c trace2:data: add subverb for rebase
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Jeff Hostetler c18b6c1a2b trace2:data: add subverb to reset command
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Jeff Hostetler e27dd8ae9f trace2:data: add subverb to checkout command
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Derrick Stolee ae417807b0 trace2:data: pack-objects: add trace2 regions
When studying the performance of 'git push' we would like to know
how much time is spent at various parts of the command. One area
that could cause performance trouble is 'git pack-objects'.

Add trace2 regions around the three main actions taken in this
command:

1. Enumerate objects.
2. Prepare pack.
3. Write pack-file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Jeff Hostetler 6206286e49 trace2:data: add trace2 hook classification
Classify certain child processes as hooks.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:28:21 -08:00
Jeff Hostetler ee4512ed48 trace2: create new combined trace facility
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:27:59 -08:00
Ævar Arnfjörð Bjarmason 9903623761 receive-pack: fix use-after-free bug
The resolve_ref_unsafe() function can, and sometimes will in the case
of this codepath, return the char * passed to it to the caller. In
this case we construct a strbuf, free it, and then continue using the
dst_name after that free().

The code being fixed dates back to da3efdb17b ("receive-pack: detect
aliased updates which can occur with symrefs", 2010-04-19). When it
was originally added it didn't have this bug, it was introduced when
it was subsequently modified to use strbuf in 6b01ecfe22 ("ref
namespaces: Support remote repositories via upload-pack and
receive-pack", 2011-07-08).

This is theoretically a security issue, the C standard makes no
guarantees that a value you use after free() hasn't been poked at or
changed by something else on the system, but in practice modern OSs
will have mapped the relevant page to this process, so nothing else
would have used it. We do no further allocations between the free()
and use-after-free, so we ourselves didn't corrupt or change the
value.

Jeff investigated that and found: "It probably would be an issue if
the allocation were larger. glibc at least will use mmap()/munmap()
after some cutoff[1], in which case we'd get a segfault from hitting
the unmapped page. But for small allocations, it just bumps brk() and
the memory is still available for further allocations after
free(). [...] If you had a sufficiently large refname you might be
able to trigger the bug [...]. I tried to push such a ref. I had to
manually make a packed-refs file with the long name to avoid
filesystem limits (though probably you could have a long a/b/c/ name
on ext4).  But the result can't actually be pushed, because it all has
to fit into a 64k pkt-line as part of the push protocol.".

An a alternative and more succinct way of implementing this would have
been to do the strbuf_release() at the end of check_aliased_update()
and use "goto out" instead of the early "return" statements. Hopefully
this approach of using a helper instead makes it easier to follow.

1. Jeff: "Weirdly, the mmap() cutoff on my glibc system is 135168
   bytes. Which is...2^17 + 2^12? 33 pages? I'm sure there's a good
   reason for that, but I didn't dig into it."

Reported-by: 王健强 <jianqiang.wang@securitygossip.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-20 15:02:12 -08:00
Nguyễn Thái Ngọc Duy 5a59a2301f completion: add more parameter value completion
This adds value completion for a couple more paramters. To make it
easier to maintain these hard coded lists, add a comment at the original
list/code to remind people to update git-completion.bash too.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-20 12:31:56 -08:00
Jeff King c2bf473d0d prune: check SEEN flag for reachability
The git-prune command checks reachability by doing a traversal, and then
checking whether a given object exists in the global object hash. This
can yield false positives if any other part of the code had to create an
object struct for some reason. It's not clear whether this is even
possible, but it's more robust to rely on something a little more
concrete: the SEEN flag set by our traversal.

Note that there is a slight possibility of regression here, as we're
relying on mark_reachable_objects() to consistently set the flag.
However, it has always done so, and we're already relying on that fact
in prune_shallow(), which is called as part of git-prune. So this is
making these two parts of the prune operation more consistent.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-14 15:25:33 -08:00
Jeff King d55a30bb1d prune: lazily perform reachability traversal
The general strategy of "git prune" is to do a full reachability walk,
then for each loose object see if we found it in our walk. But if we
don't have any loose objects, we don't need to do the expensive walk in
the first place.

This patch postpones that walk until the first time we need to see its
results.

Note that this is really a specific case of a more general optimization,
which is that we could traverse only far enough to find the object under
consideration (i.e., stop the traversal when we find it, then pick up
again when asked about the next object, etc). That could save us in some
instances from having to do a full walk. But it's actually a bit tricky
to do with our traversal code, and you'd need to do a full walk anyway
if you have even a single unreachable object (which you generally do, if
any objects are actually left after running git-repack).

So in practice this lazy-load of the full walk catches one easy but
common case (i.e., you've just repacked via git-gc, and there's nothing
unreachable).

The perf script is fairly contrived, but it does show off the
improvement:

  Test                            HEAD^             HEAD
  -------------------------------------------------------------------------
  5304.4: prune with no objects   3.66(3.60+0.05)   0.00(0.00+0.00) -100.0%

and would let us know if we accidentally regress this optimization.

Note also that we need to take special care with prune_shallow(), which
relies on us having performed the traversal. So this optimization can
only kick in for a non-shallow repository. Since this is easy to get
wrong and is not covered by existing tests, let's add an extra test to
t5304 that covers this case explicitly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-14 15:25:32 -08:00
Ramsay Jones 9b0bd87ed2 prune-packed: check for too many arguments
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-11 13:11:20 -08:00
Jean-Noël Avila 32ceace39f Fix typos in translatable strings for v2.21.0
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-11 12:58:06 -08:00
Junio C Hamano b966813e71 Merge branch 'js/rebase-i-redo-exec-fix'
For "rebase -i --reschedule-failed-exec", we do not want the "-y"
shortcut after all.

* js/rebase-i-redo-exec-fix:
  Revert "rebase: introduce a shortcut for --reschedule-failed-exec"
2019-02-08 20:44:52 -08:00
Junio C Hamano 87c9831df0 Merge branch 'nd/checkout-noisy-unmerge'
"git checkout [<tree-ish>] <pathspec>" started reporting the number
of paths that have got updated recently, but the same messages were
given when "git checkout -m <pathspec>" to unresolve conflicts that
have just been resolved.  The message now reports these unresolved
paths separately from the paths that are checked out from the index.

* nd/checkout-noisy-unmerge:
  checkout: count and print -m paths separately
  checkout: update count-checkouts messages
2019-02-08 20:44:51 -08:00
Elijah Newren d76ce4f734 log,diff-tree: add --combined-all-paths option
The combined diff format for merges will only list one filename, even if
rename or copy detection is active.  For example, with raw format one
might see:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	describe.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	phooey.c

This doesn't let us know what the original name of bar.sh was in the
first parent, and doesn't let us know what either of the original names
of phooey.c were in either of the parents.  In contrast, for non-merge
commits, raw format does provide original filenames (and a rename score
to boot).  In order to also provide original filenames for merge
commits, add a --combined-all-paths option (which must be used with
either -c or --cc, and is likely only useful with rename or copy
detection active) so that we can print tab-separated filenames when
renames are involved.  This transforms the above output to:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c	desc.c	desc.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	foo.sh	bar.sh	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	fooey.c	fuey.c	phooey.c

Further, in patch format, this changes the from/to headers so that
instead of just having one "from" header, we get one for each parent.
For example, instead of having

  --- a/phooey.c
  +++ b/phooey.c

we would see

  --- a/fooey.c
  --- a/fuey.c
  +++ b/phooey.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-07 20:15:25 -08:00
Junio C Hamano a1e19004e1 Merge branch 'ss/describe-dirty-in-the-right-directory'
"git --work-tree=$there --git-dir=$here describe --dirty" did not
work correctly as it did not pay attention to the location of the
worktree specified by the user by mistake, which has been
corrected.

* ss/describe-dirty-in-the-right-directory:
  t6120: test for describe with a bare repository
  describe: setup working tree for --dirty
2019-02-06 22:05:29 -08:00
Junio C Hamano 3a14fdec88 Merge branch 'sl/const'
Code cleanup.

* sl/const:
  various: tighten constness of some local variables
2019-02-06 22:05:28 -08:00
Junio C Hamano cba595ab1a Merge branch 'jk/loose-object-cache-oid'
Code clean-up.

* jk/loose-object-cache-oid:
  prefer "hash mismatch" to "sha1 mismatch"
  sha1-file: avoid "sha1 file" for generic use in messages
  sha1-file: prefer "loose object file" to "sha1 file" in messages
  sha1-file: drop has_sha1_file()
  convert has_sha1_file() callers to has_object_file()
  sha1-file: convert pass-through functions to object_id
  sha1-file: modernize loose header/stream functions
  sha1-file: modernize loose object file functions
  http: use struct object_id instead of bare sha1
  update comment references to sha1_object_info()
  sha1-file: fix outdated sha1 comment references
2019-02-06 22:05:27 -08:00
Junio C Hamano 96e6547c2e Merge branch 'pw/rebase-x-sanity-check'
"git rebase -x $cmd" did not reject multi-line command, even though
the command is incapable of handling such a command.  It now is
rejected upfront.

* pw/rebase-x-sanity-check:
  rebase -x: sanity check command
2019-02-06 22:05:26 -08:00
Junio C Hamano e7b120bfa5 Merge branch 'br/commit-tree-fully-spelled-gpg-sign-option'
The documentation of "git commit-tree" said that the command
understands "--gpg-sign" in addition to "-S", but the command line
parser did not know about the longhand, which has been corrected.

* br/commit-tree-fully-spelled-gpg-sign-option:
  commit-tree: add missing --gpg-sign flag
  t7510: invoke git as part of &&-chain
2019-02-06 22:05:25 -08:00