Some varargs functions that use NULL-terminated parameter list were
missing __attributes__ ((sentinel)) aka LAST_ARG_MUST_BE_NULL.
Add them.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The convention is to declare the function attribute to an extern
function together with its declaration in the header file, without
repeating the attribute declaration with its definition in the .c
source file (a file-scope static function declares its attribute
together with its definition in the .c file it is defined, as there
is no other place to do so).
The definition of git_die_config() in config.c did not follow the
convention and had its attribute declared with both its declaration
in the header and its definition in the .c source file.
Remove the one in the config.c to match everybody else.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The last part of the parameter list the function takes is like
parameters to printf. Mark it as such.
An existing call that formats a value of type size_t using "%d" was
found by the compiler with the help with this annotation; fix it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The definition of this function is in path.c but its declaration is
in worktree.h, which is something unexpected. The function is
explained as "Similar to git_path()"; declaring it next to where
git_path() is declared would make more sense.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make it clear that the interactive.singleKey configuration option is
disabled by default, using rather subtle wording that avoids an
emphasis on the actual default value. This should eliminate any
associated doubts.
While there, touch up the remaining wording of the description a bit.
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we deal with a multi-patch series in git-format-patch(1), if we see
`--interdiff` or `--range-diff` but no `--cover-letter`, we return with
an error, saying:
fatal: --range-diff requires --cover-letter or single patch
or:
fatal: --interdiff requires --cover-letter or single patch
This makes sense because the cover-letter is where we place the diff
from the previous version.
However, considering that `format-patch` generates a multi-patch as
needed, let's adopt a similar "cover as necessary" approach when using
`--interdiff` or `--range-diff`.
Therefore, relax the requirement for an explicit `--cover-letter` in a
multi-patch series when the user says `--iterdiff` or `--range-diff`.
Still, if only to return the error, respect "format.coverLetter=no" and
`--no-cover-letter`.
Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Arrange things we are going to create to be removed at end, and then
start creating them. That way, we will clean them up even if we fail
after creating some but before the end of the command.
Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up around writing the .midx files.
* tb/midx-write-cleanup:
pack-bitmap.c: reimplement `midx_bitmap_filename()` with helper
midx: replace `get_midx_rev_filename()` with a generic helper
midx-write.c: support reading an existing MIDX with `packs_to_include`
midx-write.c: extract `fill_packs_from_midx()`
midx-write.c: extract `should_include_pack()`
midx-write.c: pass `start_pack` to `compute_sorted_entries()`
midx-write.c: reduce argument count for `get_sorted_entries()`
midx-write.c: tolerate `--preferred-pack` without bitmaps
We read stdin into a strbuf, but most code paths never release it,
causing a leak (albeit a minor one, as we leak only when exiting from
the main function of the program).
Commit 56f4f4a29d (imap-send: minimum leakfix, 2024-06-04) did the
minimum to plug the one instance we see in the test suite, when we read
an empty input. But it was sufficient only because aside from this noop
invocation, we don't test imap-send at all!
The right spot to free is in the "out" label, which is hit by all code
paths before leaving the function. We couldn't do that in 56f4f4a29d
because there was no unified exit path. That came separately in
3aca5f7fb0 (imap-send: fix leaking memory in `imap_server_conf`,
2024-06-04), which cleaned up many other leaks (but not this one).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/no-writable-strings: (46 commits)
config.mak.dev: enable `-Wwrite-strings` warning
builtin/merge: always store allocated strings in `pull_twohead`
builtin/rebase: always store allocated string in `options.strategy`
builtin/rebase: do not assign default backend to non-constant field
imap-send: fix leaking memory in `imap_server_conf`
imap-send: drop global `imap_server_conf` variable
mailmap: always store allocated strings in mailmap blob
revision: always store allocated strings in output encoding
remote-curl: avoid assigning string constant to non-const variable
send-pack: always allocate receive status
parse-options: cast long name for OPTION_ALIAS
http: do not assign string constant to non-const field
compat/win32: fix const-correctness with string constants
pretty: add casts for decoration option pointers
object-file: make `buf` parameter of `index_mem()` a constant
object-file: mark cached object buffers as const
ident: add casts for fallback name and GECOS
entry: refactor how we remove items for delayed checkouts
line-log: always allocate the output prefix
line-log: stop assigning string constant to file parent buffer
...
Writing to string constants is undefined behaviour and must be avoided
in C. Even so, the compiler does not help us with this by default
because those constants are not in fact marked as `const`. This makes it
rather easy to accidentally assign a constant to a non-const variable or
field and then later on try to either free it or write to it.
Enable `-Wwrite-strings` to catch such mistakes. With this warning
enabled, the type of string constants is changed to `const char[]` and
will thus cause compiler warnings when being assigned to non-const
fields and variables.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `pull_twohead` configuration may sometimes contain an allocated
string, and sometimes it may contain a string constant. Refactor this to
instead always store an allocated string such that we can release its
resources without risk.
While at it, manage the lifetime of other config strings, as well. Note
that we explicitly don't free `cleanup_arg` here. This is because the
variable may be assigned a string constant via command line options.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct rebase_options::strategy` field is a `char *`, but we do end
up assigning string constants to it in two cases:
- When being passed a `--strategy=` option via the command line.
- When being passed a strategy option via `--strategy-option=`, but
not a strategy.
This will cause warnings once we enable `-Wwrite-strings`.
Ideally, we'd just convert the field to be a `const char *`. But we also
assign to this field via the GIT_TEST_MERGE_ALGORITHM envvar, which we
have to strdup(3P) into it.
Instead, refactor the code to make sure that we only ever assign
allocated strings to this field.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct rebase_options::default_backend` field is a non-constant
string, but is being assigned a constant via `REBASE_OPTIONS_INIT`.
Fix this by using `xstrdup()` to assign the variable and introduce a new
function `rebase_options_release()` that releases memory held by the
structure, including the newly-allocated variable.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We never free any of the config strings that we populate into the
`struct imap_server_conf`. Fix this by creating a common exit path where
we can free resources.
While at it, drop the unused member `imap_server_conf::name`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In "imap-send.c", we have a global `sturct imap_server_conf` variable
that keeps track of the configuration of the IMAP server. This variable
is being populated mostly via the Git configuration.
Refactor the code to allocate the structure on the stack instead of
having it globally. This change allows us to track its lifetime more
closely.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Same as with the preceding commit, the `git_mailmap_blob` may sometimes
contain an allocated string and sometimes it may contain a string
constant. This is risky and can easily lead to bugs in case the variable
is getting re-assigned, where the code may then try to free the previous
value to avoid memory leaks.
Safeguard the code by always storing allocated strings in the variable.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `git_log_output_encoding` variable can be set via the `--encoding=`
option. When doing so, we conditionally either assign it to the passed
value, or if the value is "none" we assign it the empty string.
Depending on which of the both code paths we pick though, the variable
may end up being assigned either an allocated string or a string
constant.
This is somewhat risky and may easily lead to bugs when a different code
path may want to reassign a new value to it, freeing the previous value.
We already to this when parsing the "i18n.logoutputencoding" config in
`git_default_i18n_config()`. But because the config is typically parsed
before we parse command line options this has been fine so far.
Regardless of that, safeguard the code such that the variable always
contains an allocated string. While at it, also free the old value in
case there was any to plug a potential memory leak.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When processing remote options, we split the option line into two by
searching for a space. If there is one, we replace the space with '\0',
otherwise we implicitly assume that the value is "true" and thus assign
a string constant.
As the return value of strchr(3P) weirdly enough is a `char *` even
though it gets a `const char *` as input, the assigned-to variable also
is a non-constant. This is fine though because the argument is in fact
an allocated string, and thus we are allowed to modify it. But this will
break once we enable `-Wwrite-strings`.
Refactor the code stop splitting the fields with '\0' altogether.
Instead, we can pass the length of the option name to `set_option()` and
then use strncmp(3P) instead of strcmp(3P).
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `receive_status()`, we record the reason why ref updates have been
rejected by the remote via the `remote_status`. But while we allocate
the assigned string when a reason was given, we assign a string constant
when no reason was given.
This has been working fine so far due to two reasons:
- We don't ever free the refs in git-send-pack(1)'
- Remotes always give a reason, at least as implemented by Git proper.
Adapt the code to always allocate the receive status string and free the
refs.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We assign the long name for OPTION_ALIAS options to a non-constant value
field. We know that the variable will never be written to, but this will
cause warnings once we enable `-Wwrite-strings`.
Cast away the constness to be prepared for this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `write_accept_language()`, we put all acceptable languages into an
array. While all entries in that array are allocated strings, the final
entry in that array is a string constant. This is fine because we
explicitly skip over the last entry when freeing the array, but will
cause warnings once we enable `-Wwrite-strings`.
Adapt the code to also allocate the final entry.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust various places in our Win32 compatibility layer where we are not
assigning string constants to `const char *` variables.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `struct decoration_options` have a prefix and suffix field which are
both non-constant, but we assign a constant pointer to them. This is
safe to do because we pass them to `format_decorations()`, which never
modifies these pointers, and then immediately discard the structure. Add
explicit casts to avoid compilation warnings with `-Wwrite-strings`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `buf` parameter of `index_mem()` is a non-constant string. This will
break once we enable `-Wwrite-strings` because we also pass constants
from at least one callsite.
Adapt the parameter to be a constant. As we cannot free the buffer
without casting now, this also requires us to move the lifetime of the
nested buffer around.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The buffers of cached objects are never modified, but are still stored
as a non-constant pointer. This will cause a compiler warning once we
enable the `-Wwrite-strings` compiler warning as we assign an empty
constant string when initializing the static `empty_tree` cached object.
Convert the field to be constant. This requires us to shuffle around
the code a bit because we memcpy(3P) into the allocated buffer in
`pretend_object_file()`. This is easily fixed though by allocating the
buffer into a temporary variable first.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `xgetpwuid_self()`, we return a fallback identity when it was not
possible to look up the current identity. This fallback identity needs
to be internal and must never be written to by the calles as specified
by getpwuid(3P). As both the `pw_name` and `pw_gecos` fields are marked
as non-constant though, it will cause a warning to assign constant
strings to them once compiling with `-Wwrite-strings`.
Add explicit casts to avoid the warning.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When finalizing a delayed checkout, we sort out several strings from the
passed-in string list by first assigning the empty string to those
filters and then calling `string_list_remove_empty_items()`. Assigning
the empty string will cause compiler warnings though as the string is
a `char *` once we enable `-Wwrite-strings`.
Refactor the code to use a `NULL` pointer with `filter_string_list()`
instead to avoid this warning.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The returned string by `output_prefix()` is sometimes a string constant
and sometimes an allocated string. This has been fine until now because
we always leak the allocated strings, and thus we never tried to free
the string constant.
Fix the code to always return an allocated string and free the returned
value at all callsites.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop assigning a string constant to the file parent buffer and instead
assign an allocated string. While the code is fine in practice, it will
break once we compile with `-Wwrite-strings`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `fill_textconv()` function is responsible for converting an input
file with a textconv driver, which is then passed to the caller. Weirdly
though, the function also handles the case where there is no textconv
driver at all. In that case, it will return either the contents of the
populated filespec, or an empty string if the filespec is invalid.
These two cases have differing memory ownership semantics. When there is
a textconv driver, then the result is an allocated string. Otherwise,
the result is either a string constant or owned by the filespec struct.
All callers are in fact aware of this weirdness and only end up freeing
the output buffer when they had a textconv driver.
Ideally, we'd split up this interface to only perform the conversion via
the textconv driver, and BUG in case the caller didn't provide one. This
would make memory ownership semantics much more straight forward. For
now though, let's simply cast the empty string constant to `char *` to
avoid a warning with `-Wwrite-strings`. This is equivalent to the same
cast that we already have in `fill_mmfile()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `get_head_names()`, we assign the "refs/heads/*" string constant to
`struct refspec_item::{src,dst}`, which are both non-constant pointers.
Ideally, we'd refactor the code such that both of these fields were
constant. But `struct refspec_item` is used for two different usecases
with conflicting requirements:
- To query for a source or destination based on the given refspec. The
caller either sets `src` or `dst` as the branch that we want to
search for, and the respective other field gets populated. The
fields should be constant when being used as a query parameter,
which is owned by the caller, and non-constant when being used as an
out parameter, which is owned by the refspec item. This is is
contradictory in itself already.
- To store refspec items with their respective source and destination
branches, in which case both fields should be owned by the struct.
Ideally, we'd split up this interface to clearly separate between
querying and storing, which would enable us to clarify lifetimes of the
strings. This would be a much bigger undertaking though.
Instead, accept the status quo for now and cast away the constness of
the source and destination patterns. We know that those are not being
written to or freed, so while this is ugly it certainly is fine for now.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a global tag refspec structure that is used by both git-clone(1)
and git-fetch(1). Initialization of the structure will break once we
enable `-Wwrite-strings`, even though the breakage is harmless. While we
could just add casts, the structure isn't really required in the first
place as we can simply initialize the structures at the respective
callsites.
Refactor the code accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reftable records are used in multiple ways throughout the reftable
library. In many of those cases they merely act as input to a function
without getting modified by it at all. Most importantly, this happens
when writing records and when querying for records.
We rely on this in our tests and thus assign string constants to those
fields, which is about to generate warnings as those fields are of type
`char *`. While we could go through the process and instead allocate
those strings in all of our tests, this feels quite unnecessary.
Instead, add casts to `char *` for all of those strings. As this is part
of our tests, this also nicely serves as a demonstration that nothing
writes or frees those string constants, which would otherwise lead to
segfaults.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When copying refs, we execute `write_copy_table()` to write the new
table. As the names are given to us via `arg->newname` and
`arg->oldname`, respectively, we optimize away some allocations by
assigning those fields to the reftable records we are about to write
directly, without duplicating them. This requires us to cast the input
to `char *` pointers as they are in fact constant strings. Later on, we
then unset the refname for all of the records before calling
`reftable_log_record_release()` on them.
We also do this when assigning the "HEAD" constant, but here we do not
cast because its type is `char[]` by default. It's about to be turned
into `const char *` though once we enable `-Wwrite-strings` and will
thus cause another warning.
It's quite dubious whether this micro-optimization really helps. We're
about to write to disk anyway, which is going to be way slower than a
small handful of allocations. Let's drop the optimization altogther and
instead copy arguments to simplify the code and avoid the future warning
with `-Wwrite-strings`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are multiple cases where we intentionally leak config strings:
- `struct gpg_format` is used to track programs that can be used for
signing commits, either via gpg(1), gpgsm(1) or ssh-keygen(1). The
user can override the commands via several config variables. As the
array is populated once, only, and the struct memers are never
written to or free'd.
- `struct ll_merge_driver` is used to track merge drivers. Same as
with the GPG format, these drivers are populated once and then
reused. Its data is never written to or free'd, either.
- `struct userdiff_funcname` and `struct userdiff_driver` can be
configured via `diff.<driver>.*` to add additional drivers. Again,
these have a global lifetime and are never written to or free'd.
All of these are intentionally kept alive and are never written to.
Furthermore, all of these are being assigned both string constants in
some places, and allocated strings in other places. This will cause
warnings once we enable `-Wwrite-strings`, so let's mark the respective
fields as `const char *` and cast away the constness when assigning
those values.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We're about to enable `-Wwrite-strings`, which changes the type of
string constants to `const char[]`. Fix various sites where we assign
such constants to non-const variables.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add 'symref-update' command to the '--stdin' mode of 'git-update-ref' to
allow updates of symbolic refs. The 'symref-update' command takes in a
<new-target>, which the <ref> will be updated to. If the <ref> doesn't
exist it will be created.
It also optionally takes either an `ref <old-target>` or `oid
<old-oid>`. If the <old-target> is provided, it checks to see if the
<ref> targets the <old-target> before the update. If <old-oid> is provided
it checks <ref> to ensure that it is a regular ref and <old-oid> is the
OID before the update. This by extension also means that this when a
zero <old-oid> is provided, it ensures that the ref didn't exist before.
The divergence in syntax from the regular `update` command is because if
we don't use a `(ref | oid)` prefix for the old_value, then there is
ambiguity around if the value provided should be treated as an oid or a
reference. This is more so the reason, because we allow anything
committish to be provided as an oid. While 'symref-verify' and
'symref-delete' also take in `<old-target>` we do not have this
divergence there as those commands only work with symrefs. Whereas
'symref-update' also works with regular refs and allows users to convert
regular refs to symrefs.
The command allows users to perform symbolic ref updates within a
transaction. This provides atomicity and allows users to perform a set
of operations together.
This command supports deref mode, to ensure that we can update
dereferenced regular refs to symrefs.
Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a reference transaction update, we can provide the old/new
oid/target for the update. We have checks in place to ensure that for
each old/new, either oid or target is set and not both.
In the reftable backend, when dealing with updates without the
`REF_NO_DEREF` flag, we don't selectively propagate data as needed.
Since there are no active users of the path, this is not caught. As we
want to introduce the 'symref-update' command in the upcoming commit,
which would use this flow, correct it.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add 'symref-create' command to the '--stdin' mode 'git-update-ref' to
allow creation of symbolic refs in a transaction. The 'symref-create'
command takes in a <new-target>, which the created <ref> will point to.
Also, support the 'core.prefersymlinkrefs' config, wherein if the config
is set and the filesystem supports symlinks, we create the symbolic ref
as a symlink. We fallback to creating a regular symref if creating the
symlink is unsuccessful.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new command 'symref-delete' to allow deletions of symbolic refs in
a transaction via the '--stdin' mode of the 'git-update-ref' command.
The 'symref-delete' command can, when given an <old-target>, delete the
provided <ref> only when it points to <old-target>.
This command is only compatible with the 'no-deref' mode because we
optionally want to check the 'old_target' of the ref being deleted.
De-referencing a symbolic ref would provide a regular ref and we already
have the 'delete' command for regular refs.
While users can also use 'git symbolic-ref -d' to delete symbolic refs,
the 'symref-delete' command in 'git-update-ref' allows users to do so
within a transaction, which promises atomicity of the operation and can
be batched with other commands.
When no 'old_target' is provided it can also delete regular refs,
similar to how the 'delete' command can delete symrefs when no 'old_oid'
is provided.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'symref-verify' command allows users to verify if a provided <ref>
contains the provided <old-target> without changing the <ref>. If
<old-target> is not provided, the command will verify that the <ref>
doesn't exist.
The command allows users to verify symbolic refs within a transaction,
and this means users can perform a set of changes in a transaction only
when the verification holds good.
Since we're checking for symbolic refs, this command will only work with
the 'no-deref' mode. This is because any dereferenced symbolic ref will
point to an object and not a ref and the regular 'verify' command can be
used in such situations.
Add required tests for symref support in 'verify'. Since we're here,
also add reflog checks for the pre-existing 'verify' tests, there is no
divergence from behavior, but we never tested to ensure that reflog
wasn't affected by the 'verify' command.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a reference update tries to update a symref, but the ref in
question is actually a regular ref, we raise an error. However the error
raised in this situation is:
verifying symref target: '<ref>': reference is missing but expected <old-target>
which is very generic and doesn't indicate the mismatch of types. Let's
make this error more specific:
cannot lock ref '<ref>': expected symref with target '<old-target>': but is a regular ref
so that users have a clearer understanding.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The files and reftable backend, need to check if a ref must exist, so
that the required validation can be done. A ref must exist only when the
`old_oid` value of the update has been explicitly set and it is not the
`null_oid` value.
Since we also support symrefs now, we need to ensure that even when
`old_target` is set a ref must exist. While this was missed when we
added symref support in transactions, there are no active users of this
path. As we introduce the 'symref-verify' command in the upcoming
commits, it is important to fix this.
So let's export this to a function called
`ref_update_expects_existing_old_ref()` and expose it internally via
'refs-internal.h'.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The update_info_file() function within server-info.c is responsible for
moving the info/refs and info/packs files around when updating server
info.
These updates are staged into a temporary file and then moved into place
atomically to avoid race conditions when reading those files. However,
the temporary file used to stage these changes is managed outside of the
tempfile.h API, and thus survives process death.
Manage these files instead with the tempfile.h API so that they are
automatically cleaned up upon abnormal process death.
Unfortunately, and unlike in the previous step, there isn't a
straightforward way to inject a failure into the update-server-info step
that causes us to die() rather than take the cleanup path in label
'out', hence the lack of a test here.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the introduction of split commit graph layers in 92b1ea66b9
(Merge branch 'ds/commit-graph-incremental', 2019-07-19), the function
write_commit_graph_file() has done the following when writing an
incremental commit-graph layer:
- used a lock_file to control access to the commit-graph-chain file
- used an auxiliary file (whose descriptor was stored in 'fd') to
write the new commit-graph layer itself
Using a lock_file to control access to the commit-graph-chain is
sensible, since only one writer may modify it at a time. Likewise, when
the commit-graph machinery is writing out a single layer, the lock_file
structure is used to modify the commit-graph itself. This is also
sensible, since the non-incremental commit-graph may also have at most
one writer.
However, using an auxiliary temporary file without using the tempfile.h
API means that writes that fail after the temporary graph layer has been
created will leave around a file in
$GIT_DIR/objects/info/commit-graphs/tmp_graph_XXXXXX
The commit-graph-chain file and non-incremental commit-graph do not
suffer from this problem as the lockfile.h API uses the tempfile.h API
transparently, so processes that died before moving those finals into
their final location cleaned up after themselves.
Ensure that the temporary file used to write incremental commit-graphs
is also managed with the tempfile.h API, to ensure that we do not ever
leave tmp_graph_XXXXXX files laying around.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
