This is a long overdue clean-up to the code for parsing and passing
diff options. It also tightens some constness issues.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Right now we don't return any error value at all from parse_date(), and if
we can't parse it, we just silently leave the result buffer unchanged.
That's fine for the current user, which will always default to the current
date, but it's a crappy interface, and we might well be better off with an
error message rather than just the default date.
So let's change the thing to return a negative value if an error occurs,
and the length of the result otherwise (snprintf behaviour: if the buffer
is too small, it returns how big it _would_ have been).
[ I started looking at this in case we could support date-based revision
names. Looks ugly. Would have to parse relative dates.. ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Add -m/--modified to show files that have been modified wrt. the index.
[jc: The original came from Brian Gerst on Sep 1st but it only checked
if the paths were cache dirty without actually checking the files were
modified. I also added the usage string and a new test.]
Signed-off-by: Junio C Hamano <junkio@cox.net>
The git port (9418) is officially listed by IANA now.
So document it.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We have deprecated the old environment variable names for quite a
while and now it's time to remove them. Gone are:
SHA1_FILE_DIRECTORIES AUTHOR_DATE AUTHOR_EMAIL AUTHOR_NAME
COMMIT_AUTHOR_EMAIL COMMIT_AUTHOR_NAME SHA1_FILE_DIRECTORY
Signed-off-by: Junio C Hamano <junkio@cox.net>
Hi. This patch contains the following possible cleanups:
* Make some needlessly global functions in local-pull.c static
* Change 'char *' to 'const char *' where appropriate
Signed-off-by: Peter Hagervall <hager@cs.umu.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This reverts 6c5f9baa3b commit, whose
change breaks gcc-2.95.
Not that I ignore portability to compilers that are properly C99, but
keeping compilation with GCC working is more important, at least for
now. We would probably end up declaring with "name[1]" and teach the
allocator to subtract one if we really aimed for portability, but that
is left for later rounds.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Omitting the first branch in ?: is a GNU extension. Cute,
but not supported by other compilers. Replaced mostly
by explicit tests. Calls to getenv() simply are repeated
on non-GNU compilers.
Signed-off-by: Jason Riedy <ejr@cs.berkeley.edu>
It cannot be checked with #ifndef, if you really think about what it
does which cannot be done only with the preprocessor. My thinko.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Not all programs necessarily have a pathspec array of pathnames, some of
them (like git-update-cache) want to do things one file at a time. So
export the single-path interface too.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We always show the diff as an absolute path, but pathnames to diff are
taken relative to the current working directory (and if no pathnames are
given, the default ends up being all of the current working directory).
Note that "../xyz" also works, so you can do
cd linux/drivers/char
git diff ../block
and it will generate a diff of the linux/drivers/block changes.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Note that the pack file has to be in the usual location if it gets
installed later.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
It was a mistake to use GIT_ALTERNATE_OBJECT_DIRECTORIES
environment variable to specify what alternate object pools to
look for missing objects when working with an object database.
It is not a property of the process running the git commands,
but a property of the object database that is partial and needs
other object pools to complete the set of objects it lacks.
This patch allows you to have $GIT_OBJECT_DIRECTORY/info/alternates
whose contents is in exactly the same format as the environment
variable, to let an object database name alternate object pools
it depends on.
Signed-off-by: Junio C Hamano <junkio@cox.net>
GCC's format __attribute__ is good for checking errors, especially
with -Wformat=2 parameter. This fixes most of the reported problems
against 2005-08-09 snapshot.
Per discussion with people interested in binary packaging,
change the default template location from /etc/git-core to
/usr/share/git-core hierarchy. If a user wants to run git
before installing for whatever reason, in addition to adding
$src to the PATH environment variable, git-init-db can be run
with --template=$src/templates/blt/ parameter.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows git-send-pack to push local refs to a destination
repository under different names.
Here is the name mapping rules for refs.
* If there is no ref mapping on the command line:
- if '--all' is specified, it is equivalent to specifying
<local> ":" <local> for all the existing local refs on the
command line
- otherwise, it is equivalent to specifying <ref> ":" <ref> for
all the refs that exist on both sides.
* <name> is just a shorthand for <name> ":" <name>
* <src> ":" <dst>
push ref that matches <src> to ref that matches <dst>.
- It is an error if <src> does not match exactly one of local
refs.
- It is an error if <dst> matches more than one remote refs.
- If <dst> does not match any remote refs, either
- it has to start with "refs/"; <dst> is used as the
destination literally in this case.
- <src> == <dst> and the ref that matched the <src> must not
exist in the set of remote refs; the ref matched <src>
locally is used as the name of the destination.
For example,
- "git-send-pack --all <remote>" works exactly as before;
- "git-send-pack <remote> master:upstream" pushes local master
to remote ref that matches "upstream". If there is no such
ref, it is an error.
- "git-send-pack <remote> master:refs/heads/upstream" pushes
local master to remote refs/heads/upstream, even when
refs/heads/upstream does not exist.
- "git-send-pack <remote> master" into an empty remote
repository pushes the local ref/heads/master to the remote
ref/heads/master.
Signed-off-by: Junio C Hamano <junkio@cox.net>
A template mechanism to populate newly initialized repository
with default set of files is introduced. Use it to ship example
hooks that can be used for update and post update checks, as
Josef Weidendorfer suggests.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This causes ssh-pull to request objects in prefetch() and read then in
fetch(), such that it reduces the unpipelined round-trip time.
This also makes sha1_write_from_fd() support having a buffer of data
which it accidentally read from the fd after the object; this was
formerly not a problem, because it would always get a short read at
the end of an object, because the next object had not been
requested. This is no longer true.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This adds support for reading an uninstalled index, and installing a
pack file that was added while the program was running, as well as
functions for determining where to put the file.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduce a new file $GIT_DIR/info/grafts (or $GIT_GRAFT_FILE)
which is a list of "fake commit parent records". Each line of
this file is a commit ID, followed by parent commit IDs, all
40-byte hex SHA1 separated by a single SP in between. The
records override the parent information we would normally read
from the commit objects, allowing both adding "fake" parents
(i.e. grafting), and pretending as if a commit is not a child of
some of its real parents (i.e. cauterizing).
Signed-off-by: Junio C Hamano <junkio@cox.net>
The git-update-server-info command prepares informational files
to help clients discover the contents of a repository, and pull
from it via a dumb transport protocols. Currently, the
following files are produced.
- The $repo/info/refs file lists the name of heads and tags
available in the $repo/refs/ directory, along with their
SHA1. This can be used by git-ls-remote command running on
the client side.
- The $repo/info/rev-cache file describes the commit ancestry
reachable from references in the $repo/refs/ directory. This
file is in an append-only binary format to make the server
side friendly to rsync mirroring scheme, and can be read by
git-show-rev-cache command.
- The $repo/objects/info/pack file lists the name of the packs
available, the interdependencies among them, and the head
commits and tags contained in them. Along with the other two
files, this is designed to help clients to make smart pull
decisions.
The git-receive-pack command is changed to invoke it at the end,
so just after a push to a public repository finishes via "git
push", the server info is automatically updated.
In addition, building of the rev-cache file can be done by a
standalone git-build-rev-cache command separately.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Moving these functions allows all of the logic for figuring out what
these values are to be shared between programs.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
... and make git-diff-files use it too. This all _should_ make the
diffcore-pathspec.c phase unnecessary, since the diff'ers now all do the
path matching early interally.
Useful for pulling stuff off a dedicated server. Instead of connecting
with ssh or just starting a local pipeline, we connect over TCP to the
other side and try to see if there's a git server listening.
Of course, since I haven't written the git server yet, that will never
happen. But the server really just needs to listen on a port, and
execute a "git-upload-pack" when somebody connects.
(It should read one packet-line, which should be of the format
"git-upload-pack directoryname\n"
and eventually we migth have other commands the server might accept).
Add write_sha1_to_fd(), which writes an object to a file descriptor. This
includes support for unpacking it and recompressing it.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes the first half of write_sha1_file() and
index_fd() externally visible, to allow callers to compute the
object ID without actually storing it in the object database.
[JC demangled the whitespaces himself because he liked the patch
so much, and reworked the interface to index_fd() slightly,
taking suggestion from Linus and of his own.]
Signed-off-by: Bryan Larsen <bryan.larsen@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The function write_one_ref() is passed the list of refs received
from the other end, which was obtained by directory traversal
under $GIT_DIR/refs; this can contain paths other than what
git-init-db prepares and would fail to clone when there is
such.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
"git_path()" returns a static pathname pointer into the git directory
using a printf-like format specifier.
"head_ref()" works like "for_each_ref()", except for just the HEAD.
This implements show_pack_info() function used in verify-pack
command when -v flag is used to obtain something like
unpack-objects used to give when it was first written.
It shows the following for each non-deltified object found in
the pack:
SHA1 type size offset
For deltified objects, it shows this instead:
SHA1 type size offset depth base_sha1
In order to get the output in the order that appear in the pack
file for debugging purposes, you can do this:
$ git-verify-pack -v packfile | sort -n -k 4,4
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Nico pointed out that having verify_pack.c and verify-pack.c was
confusing. Rename verify_pack.c to pack-check.c as suggested,
and enhances the verification done quite a bit.
- Built-in sha1_file unpacking knows that a base object of a
deltified object _must_ be in the same pack, and takes
advantage of that fact.
- Earlier verify-pack command only checked the SHA1 sum for the
entire pack file and did not look into its contents. It now
checks everything idx file claims to have unpacks correctly.
- It now has a hook to give more detailed information for
objects contained in the pack under -v flag.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's not working yet, but it's at the point where I want to be able to
track my changes. The theory of operation is that this is the "remote"
side of a "git push". It can tell us what references the remote side
has, receives out reference update commands and a pack-file, and can
execute the unpacking command.
Given a list of <pack>.idx files, this command validates the
index file and the corresponding .pack file for consistency.
This patch also uses the same validation mechanism in fsck-cache
when the --full flag is used.
During normal operation, sha1_file.c verifies that a given .idx
file matches the .pack file by comparing the SHA1 checksum
stored in .idx file and .pack file as a minimum sanity check.
We may further want to check the pack signature and version when
we map the pack, but that would be a separate patch.
Earlier, errors to map a pack file was not flagged fatal but led
to a random fatal error later. This version explicitly die()s
when such an error is detected.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The commands git-fsck-cache and probably git-*-pull needs to have a way
to enumerate objects contained in packed GIT archives and alternate
object pools. This commit exposes the data structure used to keep track
of them from sha1_file.c, and adds a couple of accessor interface
functions for use by the enhanced git-fsck-cache command.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This lets us eliminate one use of map_sha1_file() outside
sha1_file.c, to bring us one step closer to the packed GIT.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Packed delta files created by git-pack-objects seems to be the
way to go, and existing "delta" object handling code has exposed
the object representation details to too many places. Remove it
while we refactor code to come up with a proper interface in
sha1_file.c.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
An earlier change to optimize directory-file conflict check
broke what "read-tree --emu23" expects. This is fixed by this
commit.
(1) Introduces an explicit flag to tell add_cache_entry() not to
check for conflicts and use it when reading an existing tree
into an empty stage --- by definition this case can never
introduce such conflicts.
(2) Makes read-cache.c:has_file_name() and read-cache.c:has_dir_name()
aware of the cache stages, and flag conflict only with paths
in the same stage.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make 'sha1' parameters const where possible
Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds code to read a hash out of a specified file under
{GIT_DIR}/refs/, and to write such files atomically and optionally with an
compare and lock.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a "-u" flag to update the tree as a result of a merge.
Right now this code is way too anal about things, and fails merges it
shouldn't, but let me fix up the different cases and this will allow for
much smoother merging even in the presense of dirty data in the working
tree.
This adds sha1_file_size() helper function and uses it in the
rename/copy similarity estimator. The helper function handles
deltified object as well.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a remote repository is deltified, we need to get the
objects that a deltified object we want to obtain is based upon.
The initial parts of each retrieved SHA1 file is inflated and
inspected to see if it is deltified, and its base object is
asked from the remote side when it is. Since this partial
inflation and inspection has a small performance hit, it can
optionally be skipped by giving -d flag to git-*-pull commands.
This flag should be used only when the remote repository is
known to have no deltified objects.
Rsync transport does not have this problem since it fetches
everything the remote side has.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make a separate helper for parsing the header of an object file
(really carefully) and for unpacking the rest. This means that
anybody who uses the "unpack_sha1_header()" interface can easily
look at the header and decide to unpack the rest too, without
doing any extra work.
It's for people who aren't necessarily interested in the whole
unpacked file, but do want to know the header information (size,
type, etc..)
For example, the delta code can use this to figure out whether
an object is already a delta object, and what it is a delta
against, without actually bothering to unpack all of the actual
data in the delta.
Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.
This one compares two pathnames that may be partial basenames, not
full paths. We need to get the path sorting right, since a directory
name will sort as if it had the final '/' at the end.
With -u flag, git-checkout-cache picks up the stat information
from newly created file and updates the cache. This removes the
need to run git-update-cache --refresh immediately after running
git-checkout-cache.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- Raw hashes should be unsigned char.
- String functions want signed char.
- Hash and compress functions want unsigned char.
Signed-off By: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
xmalloc() and xrealloc() now take their sizes as size_t-type arguments.
Introduced complementary xcalloc().
Signed-off-by: Brad Roberts <braddr@puremagic.com>
Signed-off-by: Petr Baudis <pasky@ucw.cz>
It is kind of surprising that this was missed in the last round,
but the work tree scanner in git-ls-files was still deliberately
ignoring symlinks. This patch fixes it, so that --others will
correctly report unregistered symlinks.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Petr Baudis <pasky@ucw.cz>
This allows git to be built even with linkers which are not smart enough
to join those symbols, and makes this correct C. Pointed out by several
people.
During the mailing list discussion on renaming GIT_ environment
variables, people felt that having one environment that lets the
user (or Porcelain) specify both SHA1_FILE_DIRECTORY (now
GIT_OBJECT_DIRECTORY) and GIT_INDEX_FILE for the default layout
would be handy. This change introduces GIT_DIR environment
variable, from which the defaults for GIT_INDEX_FILE and
GIT_OBJECT_DIRECTORY are derived. When GIT_DIR is not defined,
it defaults to ".git". GIT_INDEX_FILE defaults to
"$GIT_DIR/index" and GIT_OBJECT_DIRECTORY defaults to
"$GIT_DIR/objects".
Special thanks for ideas and discussions go to Petr Baudis and
Daniel Barkalow. Bugs are mine ;-)
Signed-off-by: Junio C Hamano <junkio@cox.net>
H. Peter Anvin mentioned that using SHA1_whatever as an
environment variable name is not nice and we should instead use
names starting with "GIT_" prefix to avoid conflicts. Here is
what this patch does:
* Renames the following environment variables:
New name Old Name
GIT_AUTHOR_DATE AUTHOR_DATE
GIT_AUTHOR_EMAIL AUTHOR_EMAIL
GIT_AUTHOR_NAME AUTHOR_NAME
GIT_COMMITTER_EMAIL COMMIT_AUTHOR_EMAIL
GIT_COMMITTER_NAME COMMIT_AUTHOR_NAME
GIT_ALTERNATE_OBJECT_DIRECTORIES SHA1_FILE_DIRECTORIES
GIT_OBJECT_DIRECTORY SHA1_FILE_DIRECTORY
* Introduces a compatibility macro, gitenv(), which does an
getenv() and if it fails calls gitenv_bc(), which in turn
picks up the value from old name while giving a warning about
using an old name.
* Changes all users of the environment variable to fetch
environment variable with the new name using gitenv().
* Updates the documentation and scripts shipped with Linus GIT
distribution.
The transition plan is as follows:
* We will keep the backward compatibility list used by gitenv()
for now, so the current scripts and user environments
continue to work as before. The users will get warnings when
they have old name but not new name in their environment to
the stderr.
* The Porcelain layers should start using new names. However,
just in case it ends up calling old Plumbing layer
implementation, they should also export old names, taking
values from the corresponding new names, during the
transition period.
* After a transition period, we would drop the compatibility
support and drop gitenv(). Revert the callers to directly
call getenv() but keep using the new names.
The last part is probably optional and the transition
duration needs to be set to a reasonable value.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When "path" exists as a file or a symlink in the index, an
attempt to add "path/file" is refused because it results in file
vs directory conflict. Similarly when "path/file1",
"path/file2", etc. exist, an attempt to add "path" as a file or
a symlink is refused. With git-update-cache --replace, these
existing entries that conflict with the entry being added are
automatically removed from the cache, with warning messages.
Signed-off-by: Junio C Hamano <junkio@cox.net>
SHA1_FILE_DIRECTORIES environment variable is a colon separated paths
used when looking for SHA1 files not found in the usual place for
reading. Creating a new SHA1 file does not use this alternate object
database location mechanism. This is useful to archive older, rarely
used objects into separate directories.
Signed-off-by: Junio C Hamano <junkio@cox.net>
It didn't properly mark all cache updates as being dirty, and
causes merge errors due to that. In particular, it didn't notice
when a file was force-removed.
Besides, it was ugly as hell. I've put in place a slightly cleaner
version, but I've not enabled the optimization because I don't
want to be burned again.
Allow to store and track symlink in the repository. A symlink is stored
the same way as a regular file, only with the appropriate mode bits set.
The symlink target is therefore stored in a blob object.
This will hopefully make our udev repository fully functional. :)
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make it much safer: we write to a temporary file, and then link that
temporary file to the final destination. This avoids all the nasty
races if several people write the same object at the same time.
It should also result in nicer on-disk layout, since it means that
objects all get created in the same subdirectory. That makes a lot
of block allocation algorithms happier, since the objects will now
be allocated from the same zone.
A new command, git-write-blob, is introduced. This registers
the contents of any file on the filesystem as a blob in the
object database and reports its SHA1 to the standard output.
To implement it, the patch promotes index_fd() from a static
function in update-cache.c to extern and moves it to a library
source, sha1_file.c.
This command is used to update git-merge-one-file-script so that
it does not smudge the work tree.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This allows the programs to use various simplified versions of
the SHA1 names, eg just say "HEAD" for the SHA1 pointed to by
the .git/HEAD file etc.
For example, this commit has been done with
git-commit-tree $(git-write-tree) -p HEAD
instead of the traditional "$(cat .git/HEAD)" syntax.
...since everything out there is either strange (libc mktime has issues
with timezones) or introduces unnecessary dependencies for people (libcurl).
This goes back to the old date parsing, but moves it out into a file of
its own, and does the "struct tm" to "seconds since epoch" handling by
hand.
I grepped through the tz-database and it seems there's one "country"
left that has non-60-minute DST: Lord Howe Island. All others dropped
that before 1970.
This patch renames read_tree_with_tree_or_commit_sha1() to
read_object_with_reference() and extends it to automatically
dereference not just "commit" objects but "tag" objects. With
this patch, you can say e.g.:
ls-tree $tag
read-tree -m $(merge-base $tag $HEAD) $tag $HEAD
diff-cache $tag
diff-tree $tag $HEAD
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce xmalloc and xrealloc to die gracefully with a descriptive
message when out of memory, rather than taking a SIGSEGV.
Signed-off-by: Christopher Li<chrislgit@chrisli.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds two functions: one to check if an object is present in the local
database, and one to add an object to the local database by reading it
from a file descriptor and checking its hash.
Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This one is about a million times simpler, and much more likely to be
correct too.
Instead of trying to match up a tree object against the index, we just
read in the tree object side-by-side into the index, and just walk the
resulting index file. This was what all the read-tree cleanups were
all getting to.
This one includes the Mozilla SHA1 implementation sent in by Edgar Toernig.
It's dual-licenced under MPL-1.1 or GPL, so in the context of git, we
obviously use the GPL version.
Side note: the Mozilla SHA1 implementation is about twice as fast as the
default openssl one on my G5, but the default openssl one has optimized
x86 assembly language on x86. So choose wisely.
We use that to specify alternative index files, which can be useful
if you want to (for example) generate a temporary index file to do
some specific operation that you don't want to mess with your main
one with.
It defaults to the regular ".git/index" if it hasn't been specified.
This patch implements read_tree_with_tree_or_commit_sha1(),
which can be used when you are interested in reading an unpacked
raw tree data but you do not know nor care if the SHA1 you
obtained your user is a tree ID or a commit ID. Before this
function's introduction, you would have called read_sha1_file(),
examined its type, parsed it to call read_sha1_file() again if
it is a commit, and verified that the resulting object is a
tree. Instead, this function does that for you. It returns
NULL if the given SHA1 is not either a tree or a commit.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
