Since c6d3cce6f3 (pipe_command(): handle ENOSPC when writing to a
pipe, 2022-08-17), one `write()` call that results in an `errno` value
`ENOSPC` (which typically indicates out of disk space, which makes
little sense in the context of a pipe) is treated the same as `EAGAIN`.
However, contrary to expectations, as diagnosed in
https://github.com/python/cpython/issues/101881#issuecomment-1428667015,
when writing to a non-blocking pipe on Windows, an `errno` value of
`ENOSPC` means something else: the write _fails_. Completely. Because
more data was provided than the internal pipe buffer can handle.
Somewhat surprising, considering that `write()` is allowed to write less
than the specified amount, e.g. by writing only as much as fits in that
buffer. But it doesn't, it writes no byte at all in that instance.
Let's handle this by manually detecting when an `ENOSPC` indicates that
a pipe's buffer is smaller than what needs to be written, and re-try
using the pipe's buffer size as `size` parameter.
It would be plausible to try writing the entire buffer in a loop,
feeding pipe buffer-sized chunks, but experiments show that trying to
write more than one buffer-sized chunk right after that will immediately
fail because the buffer is unlikely to be drained as fast as `write()`
could write again. And the whole point of a non-blocking pipe is to be
non-blocking.
Which means that the logic that determines the pipe's buffer size
unfortunately has to be run potentially many times when writing large
amounts of data to a non-blocking pipe, as there is no elegant way to
cache that information between `write()` calls. It's the best we can do,
though, so it has to be good enough.
This fix is required to let t3701.60 (handle very large filtered diff)
pass with the MSYS2 runtime provided by the MSYS2 project: Without this
patch, the failed write would result in an infinite loop. This patch is
not required with Git for Windows' variant of the MSYS2 runtime only
because Git for Windows added an ugly work-around specifically to avoid
a hang in that test case.
The diff is slightly chatty because it extends an already-existing
conditional that special-cases a _different_ `errno` value for pipes,
and because this patch needs to account for the fact that
`_get_osfhandle()` potentially overwrites `errno`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"To dereference" and "to peel" were sometimes used in in-code
comments and documentation but without description in the glossary.
* vd/glossary-dereference-peel:
glossary: add definitions for dereference & peel
A few stray single quotes crept into the usage string in a2ce608244
(send-email docs: add format-patch options, 2021-10-25). Remove them.
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add 'gitglossary' definitions for "dereference" (as it used for both symrefs
and objects) and "peel". These terms are used in options and documentation
throughout Git, but they are not clearly defined anywhere and the behavior
they refer to depends heavily on context. Provide explicit definitions to
clarify existing documentation to users and help contributors to use the
most appropriate terminology possible in their additions to Git.
Update other definitions in the glossary that use the term "dereference" to
link to 'def_dereference'.
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-list --unpacked --objects" failed to exclude packed
non-commit objects, which has been corrected.
* tb/rev-list-unpacked-fix:
pack-bitmap: drop --unpacked non-commit objects from results
list-objects: drop --unpacked non-commit objects from results
Leakfix.
* ps/leakfixes:
setup: fix leaking repository format
setup: refactor `upgrade_repository_format()` to have common exit
shallow: fix memory leak when registering shallow roots
test-bloom: stop setting up Git directory twice
Another step to deprecate test_i18ngrep.
* jc/test-i18ngrep:
tests: teach callers of test_i18ngrep to use test_grep
test framework: further deprecate test_i18ngrep
"git merge-file" learns a mode to read three contents to be merged
from blob objects.
* bc/merge-file-object-input:
merge-file: add an option to process object IDs
git-merge-file doc: drop "-file" from argument placeholders
"git rev-list --missing" did not work for missing commit objects,
which has been corrected.
* kn/rev-list-missing-fix:
rev-list: add commit object support in `--missing` option
rev-list: move `show_commit()` to the bottom
revision: rename bit to `do_not_die_on_missing_objects`
Teach "git show-ref" a mode to check the existence of a ref.
* ps/show-ref:
t: use git-show-ref(1) to check for ref existence
builtin/show-ref: add new mode to check for reference existence
builtin/show-ref: explicitly spell out different modes in synopsis
builtin/show-ref: ensure mutual exclusiveness of subcommands
builtin/show-ref: refactor options for patterns subcommand
builtin/show-ref: stop using global vars for `show_one()`
builtin/show-ref: stop using global variable to count matches
builtin/show-ref: refactor `--exclude-existing` options
builtin/show-ref: fix dead code when passing patterns
builtin/show-ref: fix leaking string buffer
builtin/show-ref: split up different subcommands
builtin/show-ref: convert pattern to a local variable
The codepath to traverse the commit-graph learned to notice that a
commit is missing (e.g., corrupt repository lost an object), even
though it knows something about the commit (like its parents) from
what is in commit-graph.
* ps/do-not-trust-commit-graph-blindly-for-existence:
commit: detect commits that exist in commit-graph but not in the ODB
commit-graph: introduce envvar to disable commit existence checks
Further limit tree depth max to avoid Windows build running out of
the stack space.
* jk/tree-name-and-depth-limit:
max_tree_depth: lower it for MSVC to avoid stack overflows
When performing revision queries with `--objects` and
`--use-bitmap-index`, the output may incorrectly contain objects which
are packed, even when the `--unpacked` option is given. This affects
traversals, but also other querying operations, like `--count`,
`--disk-usage`, etc.
Like in the previous commit, the fix is to exclude those objects from
the result set before they are shown to the user (or, in this case,
before the bitmap containing the result of the traversal is enumerated
and its objects listed).
This is performed by a new function in pack-bitmap.c, called
`filter_packed_objects_from_bitmap()`. Note that we do not have to
inspect individual bits in the result bitmap, since we know that the
first N (where N is the number of objects in the bitmap's pack/MIDX)
bits correspond to objects which packed by definition.
In other words, for an object to have a bitmap position (not in the
extended index), it must appear in either the bitmap's pack or one of
the packs in its MIDX.
This presents an appealing optimization to us, which is that we can
simply memset() the corresponding number of `eword_t`'s to zero,
provided that we handle any objects which spill into the next word (but
don't occupy all 64 bits of the word itself).
We only have to handle objects in the bitmap's extended index. These
objects may (or may not) appear in one or more pack(s). Since these
objects are known to not appear in either the bitmap's MIDX or pack,
they may be stored as loose, appear in other pack(s), or both.
Before returning a bitmap containing the result of the traversal back to
the caller, drop any bits from the extended index which appear in one or
more packs. This implements the correct behavior for rev-list operations
which use the bitmap index to compute their result.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In git-rev-list(1), we describe the `--unpacked` option as:
Only useful with `--objects`; print the object IDs that are not in
packs.
This is true of commits, which we discard via get_commit_action(), but
not of the objects they reach. So if we ask for an --objects traversal
with --unpacked, we may get arbitrarily many objects which are indeed
packed.
I am nearly certain this behavior dates back to the introduction of
`--unpacked` via 12d2a18780 ("git rev-list --unpacked" shows only
unpacked commits, 2005-07-03), but I couldn't get that revision of Git
to compile for me. At least as early as v2.0.0 this has been subtly
broken:
$ git.compile --version
git version 2.0.0
$ git.compile rev-list --objects --all --unpacked
72791fe96c93f9ec5c311b8bc966ab349b3b5bbe
05713d991c18bbeef7e154f99660005311b5004d v1.0
153ed8b7719c6f5a68ce7ffc43133e95a6ac0fdb
8e4020bb5a8d8c873b25de15933e75cc0fc275df one
9200b628cf9dc883a85a7abc8d6e6730baee589c two
3e6b46e1b7e3b91acce99f6a823104c28aae0b58 unpacked.t
There, only the first, third, and sixth entries are loose, with the
remaining set of objects belonging to at least one pack.
The implications for this are relatively benign: bare 'git repack'
invocations which invoke pack-objects with --unpacked are impacted, and
at worst we'll store a few extra objects that should have been excluded.
Arguably changing this behavior is a backwards-incompatible change,
since it alters the set of objects emitted from rev-list queries with
`--objects` and `--unpacked`. But I argue that this change is still
sensible, since the existing implementation deviates from
clearly-written documentation.
The fix here is straightforward: avoid showing any non-commit objects
which are contained in packs by discarding them within list-objects.c,
before they are shown to the user. Note that similar treatment for
`list-objects.c::show_commit()` is not needed, since that case is
already handled by `revision.c::get_commit_action()`.
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Offer a slightly more verbose description of the issue fixed by
7144dee3ec (credential/libsecret: erase matching creds only, 2023-07-26)
and cb626f8e5c (credential/wincred: erase matching creds only,
2023-07-26).
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git bugreport" learned to complain when it received a command line
argument that it will not use.
* es/bugreport-no-extra-arg:
bugreport: reject positional arguments
t0091-bugreport: stop using i18ngrep