The start-up sequence of "git" needs to figure out some configured
settings before it finds and set itself up in the location of the
repository and was quite messy due to its "chicken-and-egg" nature.
The code has been restructured.
* js/early-config:
setup.c: mention unresolved problems
t1309: document cases where we would want early config not to die()
setup_git_directory_gently_1(): avoid die()ing
t1309: test read_early_config()
read_early_config(): really discover .git/
read_early_config(): avoid .git/config hack when unneeded
setup: make read_early_config() reusable
setup: introduce the discover_git_directory() function
setup_git_directory_1(): avoid changing global state
setup: prepare setup_discovered_git_dir() for the root directory
setup_git_directory(): use is_dir_sep() helper
t7006: replace dubious test
During the review of the `early-config` patch series, two issues
have been identified that have been with us forever. Mark the
identified problems for later so that we do not forget them.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function now has a new caller in addition to setup_git_directory():
the newly introduced discover_git_directory(). That function wants to
discover the current .git/ directory, and in case of a corrupted one
simply pretend that there is none to be found.
Example: if a stale .git file exists in the parent directory, and the
user calls `git -p init`, we want Git to simply *not* read any
repository config for the pager (instead of aborting with a message that
the .git file is corrupt).
Let's actually pretend that there was no GIT_DIR to be found in that case
when being called from discover_git_directory(), but keep the previous
behavior (i.e. to die()) for the setup_git_directory() case.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We modified the setup_git_directory_gently_1() function earlier to make
it possible to discover the GIT_DIR without changing global state.
However, it is still a bit cumbersome to use if you only need to figure
out the (possibly absolute) path of the .git/ directory. Let's just
provide a convenient wrapper function with an easier signature that
*just* discovers the .git/ directory.
We will use it in a subsequent patch to fix the early config.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For historical reasons, Git searches for the .git/ directory (or the
.git file) by changing the working directory successively to the parent
directory of the current directory, until either anything was found or
until a ceiling or a mount point is hit.
Further global state may be changed in case a .git/ directory was found.
We do have a use case, though, where we would like to find the .git/
directory without having any global state touched, though: when we read
the early config e.g. for the pager or for alias expansion.
Let's just move all of code that changes any global state out of the
function `setup_git_directory_gently_1()` into
`setup_git_directory_gently()`.
In subsequent patches, we will use the _1() function in a new
`discover_git_directory()` function that we will then use for the early
config code.
Note: the new loop is a *little* tricky, as we have to handle the root
directory specially: we cannot simply strip away the last component
including the slash, as the root directory only has that slash. To remedy
that, we introduce the `min_offset` variable that holds the minimal length
of an absolute path, and using that to special-case the root directory,
including an early exit before trying to find the parent of the root
directory.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, the offset parameter (indicating what part of the cwd
parameter corresponds to the current directory after discovering the
.git/ directory) is set to 0 when we are running in the root directory.
However, in the next patches we will avoid changing the current working
directory while searching for the .git/ directory, meaning that the
offset corresponding to the root directory will have to be 1 to reflect
that this directory is characterized by the path "/" (and not "").
So let's make sure that setup_discovered_git_directory() only tries to
append the trailing slash to non-root directories.
Note: the setup_bare_git_directory() does not need a corresponding
change, as it does not want to return a prefix.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git v2.12 was shipped with an embarrassing breakage where various
operations that verify paths given from the user stopped dying when
seeing an issue, and instead later triggering segfault.
* js/realpath-pathdup-fix:
real_pathdup(): fix callsites that wanted it to die on error
t1501: demonstrate NULL pointer access with invalid GIT_WORK_TREE
An helper function to make it easier to append the result from
real_path() to a strbuf has been added.
* rs/strbuf-add-real-path:
strbuf: add strbuf_add_real_path()
cocci: use ALLOC_ARRAY
In 4ac9006f83 (real_path: have callers use real_pathdup and
strbuf_realpath, 2016-12-12), we changed the xstrdup(real_path())
pattern to use real_pathdup() directly.
The problem with this change is that real_path() calls
strbuf_realpath() with die_on_error = 1 while real_pathdup() calls
it with die_on_error = 0. Meaning that in cases where real_path()
causes Git to die() with an error message, real_pathdup() is silent
and returns NULL instead.
The callers, however, are ill-prepared for that change, as they expect
the return value to be non-NULL (and otherwise the function died
with an appropriate error message).
Fix this by extending real_pathdup()'s signature to accept the
die_on_error flag and simply pass it through to strbuf_realpath(),
and then adjust all callers after a careful audit whether they would
handle NULLs well.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is okay in practice to test for forward slashes in the output of
getcwd(), because we go out of our way to convert backslashes to forward
slashes in getcwd()'s output on Windows.
Still, the correct way to test for a dir separator is by using the
helper function we introduced for that very purpose. It also serves as a
good documentation what the code tries to do (not "how").
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function for appending the canonized absolute pathname of a given
path to a strbuf. It keeps the existing contents intact, as expected of
a function of the strbuf_add() family, while avoiding copying the result
if the given strbuf is empty. It's more consistent with the rest of the
strbuf API than strbuf_realpath(), which it's wrapping.
Also add a semantic patch demonstrating its intended usage and apply it
to the current tree. Using strbuf_add_real_path() instead of calling
strbuf_addstr() and real_path() avoids an extra copy to a static buffer.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a later patch we want to react to only a subset of errors, defaulting
the rest to die as usual. Separate the block that takes care of dying
into its own function so we have easy access to it.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This follows a93bedada (setup: add gentle version of read_gitfile,
2015-06-09), and assumes the same reasoning. resolve_git_dir is unsuited
for speculative calls, so we want to use the gentle version to find out
about potential errors.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Migrate callers of real_path() who duplicate the retern value to use
real_pathdup or strbuf_realpath.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update tests that compare the strings newly marked for translation to
succeed when running under GETTEXT_POISON.
Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The repository set-up sequence has been streamlined (the biggest
change is that there is no longer git_config_early()), so that we
do not attempt to look into refs/* when we know we do not have a
Git repository.
* jk/check-repository-format:
verify_repository_format: mark messages for translation
setup: drop repository_format_version global
setup: unify repository version callbacks
init: use setup.c's repo version verification
setup: refactor repo format reading and verification
config: drop git_config_early
check_repository_format_gently: stop using git_config_early
lazily load core.sharedrepository
wrap shared_repository global in get/set accessors
setup: document check_repository_format()
A recent update 75faa45a (replace trivial malloc + sprintf / strcpy
calls with xstrfmt, 2015-09-24) rewrote
prepare an empty buffer
if (len)
append the first len bytes of "prefix" to the buffer
append "path" to the buffer
that computed "path", optionally prefixed by "prefix", into
xstrfmt("%.*s%s", len, prefix, path);
However, passing a NULL pointer to the printf(3) family of functions
to format it with %s conversion, even with the precision set to 0,
i.e.
xstrfmt("%.*s", 0, NULL)
yields undefined results, at least on some platforms.
Avoid this problem by substituting prefix with "" when len==0, as
prefix can legally be NULL in that case. This would mimick the
intent of the original code better.
Reported-by: Tom G. Christensen <tgc@jupiterrise.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Nobody reads this anymore, and they're not likely to; the
interesting thing is whether or not we passed
check_repository_format(), and possibly the individual
"extension" variables.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Once upon a time, check_repository_format_gently would parse
the config with a single callback, and that callback would
set up a bunch of global variables. But now that we have
separate workdirs, we have to be more careful. Commit
31e26eb (setup.c: support multi-checkout repo setup,
2014-11-30) introduced a reduced callback which omits some
values like core.worktree. In the "main" callback we call
the reduced one, and then add back in the missing variables.
Now that we have split the config-parsing from the munging
of the global variables, we can do it all with a single
callback, and keep all of the "are we in a separate workdir"
logic together.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we want to know if we're in a git repository of
reasonable vintage, we can call check_repository_format_gently(),
which does three things:
1. Reads the config from the .git/config file.
2. Verifies that the version info we read is sane.
3. Writes some global variables based on this.
There are a few things we could improve here.
One is that steps 1 and 3 happen together. So if the
verification in step 2 fails, we still clobber the global
variables. This is especially bad if we go on to try another
repository directory; we may end up with a state of mixed
config variables.
The second is there's no way to ask about the repository
version for anything besides the main repository we're in.
git-init wants to do this, and it's possible that we would
want to start doing so for submodules (e.g., to find out
which ref backend they're using).
We can improve both by splitting the first two steps into
separate functions. Now check_repository_format_gently()
calls out to steps 1 and 2, and does 3 only if step 2
succeeds.
Note that the public interface for read_repository_format()
and what check_repository_format_gently() needs from it are
not quite the same, leading us to have an extra
read_repository_format_1() helper. The extra needs from
check_repository_format_gently() will go away in a future
patch, and we can simplify this then to just the public
interface.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's a chicken-and-egg problem with using the regular
git_config during the repository setup process. We get
around it here by using a special interface that lets us
specify the per-repo config, and avoid calling
git_pathdup().
But this interface doesn't actually make sense. It will look
in the system and per-user config, too; we definitely would
not want to accept a core.repositoryformatversion from
there.
The git_config_from_file interface is a better match, as it
lets us look at a single file.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "shared_repository" config is loaded as part of
check_repository_format_version, but it's not quite like the
other values we check there. Something like
core.repositoryformatversion only makes sense in per-repo
config, but core.sharedrepository can be set in a per-user
config (e.g., to make all "git init" invocations shared by
default).
So it would make more sense as part of git_default_config.
Commit 457f06d (Introduce core.sharedrepository, 2005-12-22)
says:
[...]the config variable is set in the function which
checks the repository format. If this were done in
git_default_config instead, a lot of programs would need
to be modified to call git_config(git_default_config)
first.
This is still the case today, but we have one extra trick up
our sleeve. Now that we have the git_configset
infrastructure, it's not so expensive for us to ask for a
single value. So we can simply lazy-load it on demand.
This should be OK to do in general. There are some problems
with loading config before setup_git_directory() is called,
but we shouldn't be accessing the value before then (if we
were, then it would already be broken, as the variable would
not have been set by check_repository_format_version!). The
trickiest caller is git-init, but it handles the values
manually itself.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It would be useful to control access to the global
shared_repository, so that we can lazily load its config.
The first step to doing so is to make sure all access
goes through a set of functions.
This step is purely mechanical, and should result in no
change of behavior.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function's interface is rather enigmatic, so let's
document it further.
While we're here, let's also drop the return value. It will
always either be "0" or the function will die (consequently,
neither of its two callers bothered to check the return).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When setup_git_directory() is called, we set a flag in
startup_info to indicate we have a repository. But there are
a few other mechanisms by which we might set up a repo:
1. When creating a new repository via init_db(), we
transition from no-repo to being in a repo. We should
tweak this flag at that moment.
2. In enter_repo(), a stricter form of
setup_git_directory() used by server-side programs, we
check the repository format config. After doing so, we
know we're in a repository, and can set the flag.
With these changes, library code can now reliably tell
whether we are in a repository and act accordingly. We'll
leave the "prefix" field as NULL, which is what happens when
setup_git_directory() finds there is no prefix.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit a60645f (setup: remember whether repository was
found, 2010-08-05) introduced the startup_info structure,
which records some parts of the setup_git_directory()
process (notably, whether we actually found a repository or
not).
One of the uses of this data is for functions to behave
appropriately based on whether we are in a repo. But the
startup_info struct is just a pointer to storage provided by
the main program, and the only program that sets it up is
the git.c wrapper. Thus builtins have access to
startup_info, but externally linked programs do not.
Worse, library code which is accessible from both has to be
careful about accessing startup_info. This can be used to
trigger a die("BUG") via get_sha1():
$ git fast-import <<-\EOF
tag foo
from HEAD:./whatever
EOF
fatal: BUG: startup_info struct is not initialized.
Obviously that's fairly nonsensical input to feed to
fast-import, but we should never hit a die("BUG"). And there
may be other ways to trigger it if other non-builtins
resolve sha1s.
So let's point the storage for startup_info to a static
variable in setup.c, making it available to all users of the
library code. We _could_ turn startup_info into a regular
extern struct, but doing so would mean tweaking all of the
existing use sites. So let's leave the pointer indirection
in place. We can, however, drop any checks for NULL, as
they will always be false (and likewise, we can drop the
test covering this case, which was a rather artificial
situation using one of the test-* programs).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update various codepaths to avoid manually-counted malloc().
* jk/tighten-alloc: (22 commits)
ewah: convert to REALLOC_ARRAY, etc
convert ewah/bitmap code to use xmalloc
diff_populate_gitlink: use a strbuf
transport_anonymize_url: use xstrfmt
git-compat-util: drop mempcpy compat code
sequencer: simplify memory allocation of get_message
test-path-utils: fix normalize_path_copy output buffer size
fetch-pack: simplify add_sought_entry
fast-import: simplify allocation in start_packfile
write_untracked_extension: use FLEX_ALLOC helper
prepare_{git,shell}_cmd: use argv_array
use st_add and st_mult for allocation size computation
convert trivial cases to FLEX_ARRAY macros
use xmallocz to avoid size arithmetic
convert trivial cases to ALLOC_ARRAY
convert manual allocations to argv_array
argv-array: add detach function
add helpers for allocating flex-array structs
harden REALLOC_ARRAY and xcalloc against size_t overflow
tree-diff: catch integer overflow in combine_diff_path allocation
...
"git show 'HEAD:Foo[BAR]Baz'" did not interpret the argument as a
rev, i.e. the object named by the the pathname with wildcard
characters in a tree object.
* nd/dwim-wildcards-as-pathspecs:
get_sha1: don't die() on bogus search strings
check_filename: tighten dwim-wildcard ambiguity
checkout: reorder check_filename conditional
We frequently allocate strings as xmalloc(len + 1), where
the extra 1 is for the NUL terminator. This can be done more
simply with xmallocz, which also checks for integer
overflow.
There's no case where switching xmalloc(n+1) to xmallocz(n)
is wrong; the result is the same length, and malloc made no
guarantees about what was in the buffer anyway. But in some
cases, we can stop manually placing NUL at the end of the
allocated buffer. But that's only safe if it's clear that
the contents will always fill the buffer.
In each case where this patch does so, I manually examined
the control flow, and I tried to err on the side of caution.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git worktree" had a broken code that attempted to auto-fix
possible inconsistency that results from end-users moving a
worktree to different places without telling Git (the original
repository needs to maintain backpointers to its worktrees, but
"mv" run by end-users who are not familiar with that fact will
obviously not adjust them), which actually made things worse
when triggered.
* nd/do-not-move-worktree-manually:
worktree: stop supporting moving worktrees manually
worktree.c: fix indentation
When specifying both revisions and pathnames, we allow
"<rev> -- <pathspec>" to be spelled without the "--" as long
as it is not ambiguous. The original logic was something
like:
1. Resolve each item with get_sha1(). If successful,
we know it can be a <rev>. Verify that it _isn't_ a
filename, using verify_non_filename(), and complain of
ambiguity otherwise.
2. If get_sha1() didn't succeed, make sure that it _is_
a file, using verify_filename(). If not, complain
that it is neither a <rev> nor a <pathspec>.
Both verify_filename() and verify_non_filename() rely on
check_filename(), which definitely said "yes, this is a
file" or "no, it is not" using lstat().
Commit 28fcc0b (pathspec: avoid the need of "--" when
wildcard is used, 2015-05-02) introduced a convenience
feature: check_filename() will consider anything with
wildcard meta-characters as a possible filename, without
even checking the filesystem.
This works well for case 2. For such a wildcard, we would
previously have died and said "it is neither". Post-28fcc0b,
we assume it's a pathspec and proceed.
But it makes some instances of case 1 worse. We may have an
extended sha1 expression that contains meta-characters
(e.g., "HEAD^{/foo.*bar}"), and we now complain that it's
also a filename, due to the wildcard characters (even though
that wildcard would not match anything in the filesystem).
One solution would be to actually expand the pathname and
see if it matches anything on the filesystem. But that's
potentially expensive, and we do not have to be so rigorous
for this DWIM magic (if you want rigor, use "--").
Instead, we can just use different rules for cases 1 and 2.
When we know something is a rev, we will complain only if it
meets a much higher standard for "this is also a file";
namely that it actually exists in the filesystem. Case 2
remains the same: we use the looser "it could be a filename"
standard introduced by 28fcc0b.
We can accomplish this by pulling the wildcard logic out of
check_filename() and putting it into verify_filename(). Its
partner verify_non_filename() does not need a change, since
check_filename() goes back to implementing the "higher
standard".
Besides these two callers of check_filename(), there is one
other: git-checkout does a similar DWIM itself. It hits this
code path only after get_sha1() has returned failure, making
it case 2, which gets the special wildcard treatment.
Note that we drop the tests in t2019 in favor of a more
complete set in t6133. t2019 was not the right place for
them (it's about refname ambiguity, not dwim parsing
ambiguity), and the second test explicitly checked for the
opposite result of the case we are fixing here (which didn't
really make any sense; as shown by the test_must_fail in the
test, it would only serve to annoy people).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have always had is_git_directory(), for looking at a
specific directory to see if it contains a git repo. In
0179ca7 (clean: improve performance when removing lots of
directories, 2015-06-15), we added is_git_repository() which
checks for a non-bare repository by looking at its ".git"
entry.
However, the fix in 0179ca7 needs to be applied other
places, too. Let's make this new helper globally available.
We need to give it a better name, though, to avoid confusion
with is_git_directory(). This patch does that, documents
both functions with a comment to reduce confusion, and
removes the clean-specific references in the comments.
Based-on-a-patch-by: Andreas Krey <a.krey@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current update_linked_gitdir() has a bug that can create "gitdir"
file in non-multi-worktree setup. Worse, sometimes it can write relative
path to "gitdir" file, which will not work (e.g. "git worktree list"
will display the worktree's location incorrectly)
Instead of fixing this, we step back a bit. The original design was
probably not well thought out. For now, if the user manually moves a
worktree, they have to fix up "gitdir" file manually or the worktree
will get pruned.
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare for Git on-disk repository representation to undergo
backward incompatible changes by introducing a new repository
format version "1", with an extension mechanism.
* jk/repository-extension:
introduce "preciousObjects" repository extension
introduce "extensions" form of core.repositoryformatversion
Many allocations that is manually counted (correctly) that are
followed by strcpy/sprintf have been replaced with a less error
prone constructs such as xstrfmt.
Macintosh-specific breakage was noticed and corrected in this
reroll.
* jk/war-on-sprintf: (70 commits)
name-rev: use strip_suffix to avoid magic numbers
use strbuf_complete to conditionally append slash
fsck: use for_each_loose_file_in_objdir
Makefile: drop D_INO_IN_DIRENT build knob
fsck: drop inode-sorting code
convert strncpy to memcpy
notes: document length of fanout path with a constant
color: add color_set helper for copying raw colors
prefer memcpy to strcpy
help: clean up kfmclient munging
receive-pack: simplify keep_arg computation
avoid sprintf and strcpy with flex arrays
use alloc_ref rather than hand-allocating "struct ref"
color: add overflow checks for parsing colors
drop strcpy in favor of raw sha1_to_hex
use sha1_to_hex_r() instead of strcpy
daemon: use cld->env_array when re-spawning
stat_tracking_info: convert to argv_array
http-push: use an argv_array for setup_revisions
fetch-pack: use argv_array for index-pack / unpack-objects
...
It's a common pattern to do:
foo = xmalloc(strlen(one) + strlen(two) + 1 + 1);
sprintf(foo, "%s %s", one, two);
(or possibly some variant with strcpy()s or a more
complicated length computation). We can switch these to use
xstrfmt, which is shorter, involves less error-prone manual
computation, and removes many sprintf and strcpy calls which
make it harder to audit the code for real buffer overflows.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When submodule is a linked worktree, "git diff --submodule" and other
calls which directly access the submodule's object database do not correctly
calculate its path. Fix it by changing the git_pathdup_submodule() behavior,
to use either common or per-worktree directory.
Do it similarly as for parent repository, but ignore the GIT_COMMON_DIR
environment variable, because it would mean common directory for the parent
repository and does not make sense for submodule.
Also add test for functionality which uses this call.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code in "multiple-worktree" support that attempted to recover
from an inconsistent state updated an incorrect file.
* nd/fixup-linked-gitdir:
setup: update the right file in multiple checkouts
All of the callsites covered by this change call write_file() or
write_file_gently() to create a one-liner file. Drop the caller
supplied LF and let these callees to append it as necessary.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code is introduced in 23af91d (prune: strategies for linked
checkouts - 2014-11-30), and it's supposed to implement this rule from
that commit's message:
- linked checkouts are supposed to keep its location in $R/gitdir up
to date. The use case is auto fixup after a manual checkout move.
Note the name, "$R/gitdir", not "$R/gitfile". Correct the path to be
updated accordingly.
While at there, make sure I/O errors are not silently dropped.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All callers except three passed 1 for the "fatal" parameter to ask
this function to die upon error, but to a casual reader of the code,
it was not all obvious what that 1 meant. Instead, split the
function into two based on a common write_file_v() that takes the
flag, introduce write_file_gently() as a new way to attempt creating
a file without dying on error, and make three callers to call it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace "is this subdirectory a separate repository that should not
be touched?" check "git clean" does by checking if it has .git/HEAD
using the submodule-related code with a more optimized check.
* ee/clean-remove-dirs:
read_gitfile_gently: fix use-after-free
clean: improve performance when removing lots of directories
p7300: add performance tests for clean
t7300: add tests to document behavior of clean and nested git
setup: sanity check file size in read_gitfile_gently
setup: add gentle version of read_gitfile
The "dir" variable is a pointer into the "buf" array. When
we hit the cleanup_return path, the first thing we do is
free(buf); but one of the error messages prints "dir", which
will access the memory after the free.
We can fix this by reorganizing the error path a little. We
act on the fatal, error-printing conditions first, as they
want to access memory and do not care about freeing. Then we
free any memory, and finally return.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If this extension is used in a repository, then no
operations should run which may drop objects from the object
storage. This can be useful if you are sharing that storage
with other repositories whose refs you cannot see.
For instance, if you do:
$ git clone -s parent child
$ git -C parent config extensions.preciousObjects true
$ git -C parent config core.repositoryformatversion 1
you now have additional safety when running git in the
parent repository. Prunes and repacks will bail with an
error, and `git gc` will skip those operations (it will
continue to pack refs and do other non-object operations).
Older versions of git, when run in the repository, will
fail on every operation.
Note that we do not set the preciousObjects extension by
default when doing a "clone -s", as doing so breaks
backwards compatibility. It is a decision the user should
make explicitly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Normally we try to avoid bumps of the whole-repository
core.repositoryformatversion field. However, it is
unavoidable if we want to safely change certain aspects of
git in a backwards-incompatible way (e.g., modifying the set
of ref tips that we must traverse to generate a list of
unreachable, safe-to-prune objects).
If we were to bump the repository version for every such
change, then any implementation understanding version `X`
would also have to understand `X-1`, `X-2`, and so forth,
even though the incompatibilities may be in orthogonal parts
of the system, and there is otherwise no reason we cannot
implement one without the other (or more importantly, that
the user cannot choose to use one feature without the other,
weighing the tradeoff in compatibility only for that
particular feature).
This patch documents the existing repositoryformatversion
strategy and introduces a new format, "1", which lets a
repository specify that it must run with an arbitrary set of
extensions. This can be used, for example:
- to inform git that the objects should not be pruned based
only on the reachability of the ref tips (e.g, because it
has "clone --shared" children)
- that the refs are stored in a format besides the usual
"refs" and "packed-refs" directories
Because we bump to format "1", and because format "1"
requires that a running git knows about any extensions
mentioned, we know that older versions of the code will not
do something dangerous when confronted with these new
formats.
For example, if the user chooses to use database storage for
refs, they may set the "extensions.refbackend" config to
"db". Older versions of git will not understand format "1"
and bail. Versions of git which understand "1" but do not
know about "refbackend", or which know about "refbackend"
but not about the "db" backend, will refuse to run. This is
annoying, of course, but much better than the alternative of
claiming that there are no refs in the repository, or
writing to a location that other implementations will not
read.
Note that we are only defining the rules for format 1 here.
We do not ever write format 1 ourselves; it is a tool that
is meant to be used by users and future extensions to
provide safety with older implementations.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The setup code used to die when core.bare and core.worktree are set
inconsistently, even for commands that do not need working tree.
* jk/die-on-bogus-worktree-late:
setup_git_directory: delay core.bare/core.worktree errors
read_gitfile_gently will allocate a buffer to fit the entire file that
should be read. Add a sanity check of the file size before opening to
avoid allocating a potentially huge amount of memory if we come across
a large file that someone happened to name ".git". The limit is set to
a sufficiently unreasonable size that should never be exceeded by a
genuine .git file.
Signed-off-by: Erik Elfström <erik.elfstrom@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
