This adds the counterpart of git-update-ref that lets you read
and create "symbolic refs". By default it uses a symbolic link
to represent ".git/HEAD -> refs/heads/master", but it can be compiled
to use the textfile symbolic ref.
The places that did 'readlink .git/HEAD' and 'ln -s refs/heads/blah
.git/HEAD' have been converted to use new git-symbolic-ref command, so
that they can deal with either implementation.
Signed-off-by: Junio C Hamano <junio@twinsun.com>
Symbolic refs are understood by resolve_ref(), so existing read_ref()
users will automatically understand them as well.
Signed-off-by: Junio C Hamano <junio@twinsun.com>
This extends the ref reading to understand a "symbolic ref": a ref file
that starts with "ref: " and points to another ref file, and thus
introduces the notion of ref aliases.
This is in preparation of allowing HEAD to eventually not be a symlink,
but one of these symbolic refs instead.
[jc: Linus originally required the prefix to be "ref: " five bytes
and nothing else, but I changed it to allow and strip any number of
leading whitespaces to match what update-ref.c does.]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Because there is no reason not to, and this makes things a bit
safer when running "git prune".
[jc: I do not necessarily agree with the reasoning of the
original author that it is a good way to keep "git prune" from
stomping on objects to have a symlink that points at .git/refs
of the repository A in the .git/refs of the repository B when
repository A borrows object database from repository B. For one
thing, the object database that everybody borrows objects from
may not even have its own .git/refs hierarchy. Come to think of
it, maybe we should disallow symlink inside .git/refs hierarchy;
we update the files there by creat/rename pair, so having
symlinks would not work anyway when you do anything that would
update them.]
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.
It always uses a git-relative pathname, ie "refs/heads/master" instead of
".git/refs/heads/master" or whatever your GIT_DIR might be.
This way when we send refs back-and-forth between repositories, there's
never any question about GIT_DIR on either side.
"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 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>
