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()
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 are no more callers, and it's a rather confusing
interface. This could just be folded into
git_config_with_options(), but for the sake of readability,
we'll leave it as a separate (static) helper function.
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>
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>
The code to read the pack data using the offsets stored in the pack
idx file has been made more carefully check the validity of the
data in the idx.
* jk/pack-idx-corruption-safety:
sha1_file.c: mark strings for translation
use_pack: handle signed off_t overflow
nth_packed_object_offset: bounds-check extended offset
t5313: test bounds-checks of corrupted/malicious pack/idx files
Many codepaths forget to check return value from git_config_set();
the function is made to die() to make sure we do not proceed when
setting a configuration variable failed.
* ps/config-error:
config: rename git_config_set_or_die to git_config_set
config: rename git_config_set to git_config_set_gently
compat: die when unable to set core.precomposeunicode
sequencer: die on config error when saving replay opts
init-db: die on config errors when initializing empty repo
clone: die on config error in cmd_clone
remote: die on config error when manipulating remotes
remote: die on config error when setting/adding branches
remote: die on config error when setting URL
submodule--helper: die on config error when cloning module
submodule: die on config error when linking modules
branch: die on config error when editing branch description
branch: die on config error when unsetting upstream
branch: report errors in tracking branch setup
config: introduce set_or_die wrappers
The configuration system has been taught to phrase where it found a
bad configuration variable in a better way in its error messages.
"git config" learnt a new "--show-origin" option to indicate where
the values come from.
* ls/config-origin:
config: add '--show-origin' option to print the origin of a config value
config: add 'origin_type' to config_source struct
rename git_config_from_buf to git_config_from_mem
t: do not hide Git's exit code in tests using 'nul_to_q'
If a pack .idx file has a corrupted offset for an object, we
may try to access an offset in the .idx or .pack file that
is larger than the file's size. For the .pack case, we have
use_pack() to protect us, which realizes the access is out
of bounds. But if the corrupted value asks us to look in the
.idx file's secondary 64-bit offset table, we blindly add it
to the mmap'd index data and access arbitrary memory.
We can fix this with a simple bounds-check compared to the
size we found when we opened the .idx file.
Note that there's similar code in index-pack that is
triggered only during "index-pack --verify". To support
both, we pull the bounds-check into a separate function,
which dies when it sees a corrupted file.
It would be nice if we could return an error, so that the
pack code could try to find a good copy of the object
elsewhere. Currently nth_packed_object_offset doesn't have
any way to return an error, but it could probably use "0" as
a sentinel value (since no object can start there). This is
the minimal fix, and we can improve the resilience later on
top.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "v(iew)" subcommand of the interactive "git am -i" command was
broken in 2.6.0 timeframe when the command was rewritten in C.
* jc/am-i-v-fix:
am -i: fix "v"iew
pager: factor out a helper to prepare a child process to run the pager
pager: lose a separate argv[]
Rename git_config_set_or_die functions to git_config_set, leading
to the new default behavior of dying whenever a configuration
error occurs.
By now all callers that shall die on error have been transitioned
to the _or_die variants, thus making this patch a simple rename
of the functions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The desired default behavior for `git_config_set` is to die
whenever an error occurs. Dying is the default for a lot of
internal functions when failures occur and is in this case the
right thing to do for most callers as otherwise we might run into
inconsistent repositories without noticing.
As some code may rely on the actual return values for
`git_config_set` we still require the ability to invoke these
functions without aborting. Rename the existing `git_config_set`
functions to `git_config_set_gently` to keep them available for
those callers.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the config origin_type to print more detailed error messages that
inform the user about the origin of a config error (file, stdin, blob).
Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This matches the naming used in the index_{fd,mem,...} functions.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running a pager, we need to run the program git_pager() gave
us, but we need to make sure we spawn it via the shell (i.e. it is
valid to say PAGER='less -S', for example) and give default values
to $LESS and $LV environment variables. Factor out these details
to a separate helper function.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A lot of call-sites for the existing family of `git_config_set`
functions do not check for errors that may occur, e.g. when the
configuration file is locked. In many cases we simply want to die
when such a situation arises.
Introduce wrappers that will cause the program to die in those
cases. These wrappers are temporary only to ease the transition
to let `git_config_set` die by default. They will be removed
later on when `git_config_set` itself has been replaced by
`git_config_set_gently`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The underlying machinery used by "ls-files -o" and other commands
have been taught not to create empty submodule ref cache for a
directory that is not a submodule. This removes a ton of wasted
CPU cycles.
* jk/ref-cache-non-repository-optim:
resolve_gitlink_ref: ignore non-repository paths
clean: make is_git_repository a public function
A few unportable C construct have been spotted by clang compiler
and have been fixed.
* jk/clang-pedantic:
bswap: add NO_UNALIGNED_LOADS define
avoid shifting signed integers 31 bits
The underlying machinery used by "ls-files -o" and other commands
have been taught not to create empty submodule ref cache for a
directory that is not a submodule. This removes a ton of wasted
CPU cycles.
* jk/ref-cache-non-repository-optim:
resolve_gitlink_ref: ignore non-repository paths
clean: make is_git_repository a public function
To correctly perform its testing function,
test-dump-untracked-cache should not change the state of the
untracked cache in the index.
As a previous patch makes read_index_from() change the state of
the untracked cache and as test-dump-untracked-cache indirectly
calls this function, we need a mechanism to prevent
read_index_from() from changing the untracked cache state when
it's called from test-dump-untracked-cache.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we know that mtime on directory as given by the environment
is usable for the purpose of untracked cache, we may want the
untracked cache to be always used without any mtime test or
kernel name check being performed.
Also when we know that mtime is not usable for the purpose of
untracked cache, for example because the repo is shared over a
network file system, we may want the untracked-cache to be
automatically removed from the index.
Allow the user to express such preference by setting the
'core.untrackedCache' configuration variable, which can take
'keep', 'false', or 'true' and default to 'keep'.
When read_index_from() is called, it now adds or removes the
untracked cache in the index to respect the value of this
variable. So it does nothing if the value is `keep` or if the
variable is unset; it adds the untracked cache if the value is
`true`; and it removes the cache if the value is `false`.
`git update-index --[no-|force-]untracked-cache` still adds the
untracked cache to, or removes it, from the index, but this
shows a warning if it goes against the value of
core.untrackedCache, because the next time the index is read
the untracked cache will be added or removed if the
configuration is set to do so.
Also `--untracked-cache` used to check that the underlying
operating system and file system change `st_mtime` field of a
directory if files are added or deleted in that directory. But
because those tests take a long time, `--untracked-cache` no
longer performs them. Instead, there is now
`--test-untracked-cache` to perform the tests. This change
makes `--untracked-cache` the same as `--force-untracked-cache`.
This last change is backward incompatible and should be
mentioned in the release notes.
Helped-by: Duy Nguyen <pclouds@gmail.com>
Helped-by: Torsten Bögershausen <tboegi@web.de>
Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
read-cache: Duy'sfixup
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
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>
A few unportable C construct have been spotted by clang compiler
and have been fixed.
* jk/clang-pedantic:
bswap: add NO_UNALIGNED_LOADS define
avoid shifting signed integers 31 bits
Paths that have been told the index about with "add -N" are not
quite yet in the index, but a few commands behaved as if they
already are in a harmful way.
* nd/ita-cleanup:
grep: make it clear i-t-a entries are ignored
add and use a convenience macro ce_intent_to_add()
blame: remove obsolete comment
In-core storage of the reverse index for .pack files (which lets
you go from a pack offset to an object name) has been streamlined.
* jk/pack-revindex:
pack-revindex: store entries directly in packed_git
pack-revindex: drop hash table
We sometimes use 32-bit unsigned integers as bit-fields.
It's fine to access the MSB, because it's unsigned. However,
doing so as "1 << 31" is wrong, because the constant "1" is
a signed int, and we shift into the sign bit, causing
undefined behavior.
We can fix this by using "1U" as the constant.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A pack_revindex struct has two elements: the revindex
entries themselves, and a pointer to the packed_git. We need
both to do lookups, because only the latter knows things
like the number of objects in the pack.
Now that packed_git contains the pack_revindex struct it's
just as easy to pass around the packed_git itself, and we do
not need the extra back-pointer.
We can instead just store the entries directly in the pack.
All functions which took a pack_revindex now just take a
packed_git. We still lazy-load in find_pack_revindex, so
most callers are unaffected.
The exception is the bitmap code, which computes the
revindex and caches the pointer when we load the bitmaps. We
can continue to load, drop the extra cache pointer, and just
access bitmap_git.pack.revindex directly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The main entry point to the pack-revindex code is
find_pack_revindex(). This calls revindex_for_pack(), which
lazily computes and caches the revindex for the pack.
We store the cache in a very simple hash table. It's created
by init_pack_revindex(), which inserts an entry for every
packfile we know about, and we never grow or shrink the
hash. If we ever need the revindex for a pack that isn't in
the hash, we die() with an internal error.
This can lead to a race, because we may load more packs
after having called init_pack_revindex(). For example,
imagine we have one process which needs to look at the
revindex for a variety of objects (e.g., cat-file's
"%(objectsize:disk)" format). Simultaneously, git-gc is
running, which is doing a `git repack -ad`. We might hit a
sequence like:
1. We need the revidx for some packed object. We call
find_pack_revindex() and end up in init_pack_revindex()
to create the hash table for all packs we know about.
2. We look up another object and can't find it, because
the repack has removed the pack it's in. We re-scan the
pack directory and find a new pack containing the
object. It gets added to our packed_git list.
3. We call find_pack_revindex() for the new object, which
hits revindex_for_pack() for our new pack. It can't
find the packed_git in the revindex hash, and dies.
You could also replace the `repack` above with a push or
fetch to create a new pack, though these are less likely
(you would have to somehow learn about the new objects to
look them up).
Prior to 1a6d8b9 (do not discard revindex when re-preparing
packfiles, 2014-01-15), this was safe, as we threw away the
revindex whenever we re-scanned the pack directory (and thus
re-created the revindex hash on the fly). However, we don't
want to simply revert that commit, as it was solving a
different race.
So we have a few options:
- We can fix the race in 1a6d8b9 differently, by having
the bitmap code look in the revindex hash instead of
caching the pointer. But this would introduce a lot of
extra hash lookups for common bitmap operations.
- We could teach the revindex to dynamically add new packs
to the hash table. This would perform the same, but
would mean adding extra code to the revindex hash (which
currently cannot be resized at all).
- We can get rid of the hash table entirely. There is
exactly one revindex per pack, so we can just store it
in the packed_git struct. Since it's initialized lazily,
it does not add to the startup cost.
This is the best of both worlds: less code and fewer
hash table lookups. The original code likely avoided
this in the name of encapsulation. But the packed_git
and reverse_index code are fairly intimate already, so
it's not much of a loss.
This patch implements the final option. It's a minimal
conversion that retains the pack_revindex struct. No callers
need to change, and we can do further cleanup in a follow-on
patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"format-patch" has learned a new option to zero-out the commit
object name on the mbox "From " line.
* bc/format-patch-null-from-line:
format-patch: check that header line has expected format
format-patch: add an option to suppress commit hash
sha1_file.c: introduce a null_oid constant
null_oid is the struct object_id equivalent to null_sha1.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More transition from "unsigned char[40]" to "struct object_id".
This needed a few merge fixups, but is mostly disentangled from other
topics.
* bc/object-id:
remote: convert functions to struct object_id
Remove get_object_hash.
Convert struct object to object_id
Add several uses of get_object_hash.
object: introduce get_object_hash macro.
ref_newer: convert to use struct object_id
push_refs_with_export: convert to struct object_id
get_remote_heads: convert to struct object_id
parse_fetch: convert to use struct object_id
add_sought_entry_mem: convert to struct object_id
Convert struct ref to use object_id.
sha1_file: introduce has_object_file helper.
Code preparation for pluggable ref backends.
* dt/refs-backend-pre-vtable:
refs: break out ref conflict checks
files_log_ref_write: new function
initdb: make safe_create_dir public
refs: split filesystem-based refs code into a new file
refs/refs-internal.h: new header file
refname_is_safe(): improve docstring
pack_if_possible_fn(): use ref_type() instead of is_per_worktree_ref()
copy_msg(): rename to copy_reflog_msg()
verify_refname_available(): new function
verify_refname_available(): rename function
Apple's common crypto implementation of SHA1_Update() does not take
more than 4GB at a time, and we now have a compile-time workaround
for it.
* ad/sha1-update-chunked:
sha1: allow limiting the size of the data passed to SHA1_Update()
sha1: provide another level of indirection for the SHA-1 functions
Having a leftover .idx file without corresponding .pack file in
the repository hurts performance; "git gc" learned to prune them.
We may want to do the same for .bitmap (and notice but not prune
.keep) without corresponding .pack, but that can be a separate
topic.
* dk/gc-idx-wo-pack:
gc: remove garbage .idx files from pack dir
t5304: test cleaning pack garbage
prepare_packed_git(): refactor garbage reporting in pack directory
Apple's common crypto implementation of SHA1_Update() does not take
more than 4GB at a time, and we now have a compile-time workaround
for it.
* ad/sha1-update-chunked:
sha1: allow limiting the size of the data passed to SHA1_Update()
sha1: provide another level of indirection for the SHA-1 functions
Add has_object_file, which is a wrapper around has_sha1_file, but for
struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Having a leftover .idx file without corresponding .pack file in
the repository hurts performance; "git gc" learned to prune them.
* dk/gc-idx-wo-pack:
gc: remove garbage .idx files from pack dir
t5304: test cleaning pack garbage
prepare_packed_git(): refactor garbage reporting in pack directory
Soon we will want to create initdb functions for ref backends, and
code from initdb that calls this function needs to move into the files
backend. So this function needs to be public.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Using the previous commit's inredirection mechanism for SHA1,
support a chunked implementation of SHA1_Update() that limits the
amount of data in the chunk passed to SHA1_Update().
This is enabled by using the Makefile variable SHA1_MAX_BLOCK_SIZE
to specify chunk size. When using Apple's CommonCrypto library this
is set to 1GiB (the implementation cannot handle more 4GiB).
Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git source uses git_SHA1_Update() and friends to call into the
code that computes the hashes. Traditionally, we used to map these
directly to underlying implementation of the SHA-1 hash (e.g.
SHA1_Update() from OpenSSL or blk_SHA1_Update() from block-sha1/).
This arrangement however makes it hard to tweak behaviour of the
underlying implementation without fully replacing. If we want to
introduce a tweaked_SHA1_Update() wrapper to implement the "Update"
in a slightly different way, for example, the implementation of the
wrapper still would want to call into the underlying implementation,
but tweaked_SHA1_Update() cannot call git_SHA1_Update() to get to
the underlying implementation (often but not always SHA1_Update()).
Add another level of indirection that maps platform_SHA1_Update()
and friends to their underlying implementations, and by default make
git_SHA1_Update() and friends map to platform_SHA1_* functions.
Doing it this way will later allow us to map git_SHA1_Update() to
tweaked_SHA1_Update(), and the latter can use platform_SHA1_Update()
in its implementation.
Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The name-hash subsystem that is used to cope with case insensitive
filesystems keeps track of directories and their on-filesystem
cases for all the paths in the index by holding a pointer to a
randomly chosen cache entry that is inside the directory (for its
ce->ce_name component). This pointer was not updated even when the
cache entry was removed from the index, leading to use after free.
This was fixed by recording the path for each directory instead of
borrowing cache entries and restructuring the API somewhat.
* dt/name-hash-dir-entry-fix:
name-hash: don't reuse cache_entry in dir_entry
The submodule code has been taught to work better with separate
work trees created via "git worktree add".
* mk/submodule-gitdir-path:
path: implement common_dir handling in git_pathdup_submodule()
submodule refactor: use strbuf_git_path_submodule() in add_submodule_odb()
"git clone --dissociate" runs a big "git repack" process at the
end, and it helps to close file descriptors that are open on the
packs and their idx files before doing so on filesystems that
cannot remove a file that is still open.
* js/clone-dissociate:
clone --dissociate: avoid locking pack files
sha1_file.c: add a function to release all packs
sha1_file: consolidate code to close a pack's file descriptor
t5700: demonstrate a Windows file locking issue with `git clone --dissociate`
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
The name-hash subsystem that is used to cope with case insensitive
filesystems keeps track of directories and their on-filesystem
cases for all the paths in the index by holding a pointer to a
randomly chosen cache entry that is inside the directory (for its
ce->ce_name component). This pointer was not updated even when the
cache entry was removed from the index, leading to use after free.
This was fixed by recording the path for each directory instead of
borrowing cache entries and restructuring the API somewhat.
* dt/name-hash-dir-entry-fix:
name-hash: don't reuse cache_entry in dir_entry
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
