In order to do partial commits, git-commit overlays a tree on the
cache and checks pathspecs against the result. Currently, the
overlaying is done using "prefix" which prevents relative pathspecs
with ".." and absolute pathspec from matching when they refer to
files not under "prefix" and absent from the index, but still in
the tree (i.e.  files staged for removal).

The point of providing a prefix at all is performance optimization.
If we say there is no common prefix for the files of interest, then
we have to read the entire tree into the index.

But even if we cannot use the working directory as a prefix, we can
still figure out if there is a common prefix for all given paths,
and use that instead. The pathspec_prefix() routine from ls-files.c
does exactly that.

Any use of global variables is removed from pathspec_prefix() so
that it can be called from commit.c.
Reported-by: NReuben Thomas <rrt@sc3d.org>
Analyzed-by: NMichael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Otherwise, a negative error return becomes a very large read
value. We catch this in practice because we compare the
expected and actual numbers of bytes (and you are not likely
to be reading (size_t)-1 bytes), but this makes the
correctness a little more obvious.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In particular, sparse issues the "symbol 'a_symbol' was not declared.
Should it be static?" warnings for the following symbols:

    setup.c:159:3: 'pathspec_magic'
    setup.c:176:12: 'prefix_pathspec'

These symbols only require file scope, so we add the static modifier
to their declarations.
Signed-off-by: NRamsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A colon followed by anything !isalnum() (e.g. ":/heh") at this point is
known not to be an existing rev.  Just give a generic "neither a rev nor
a path" error message.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git cmd :/no-such-string-ever-existed" runs an extra round of get_sha1()
since 009fee47 (Detailed diagnosis when parsing an object name fails.,
2009-12-07).  Once without error diagnosis to see there is no commit with
such a string in the log message (hence "it cannot be a ref"), and after
seeing that :/no-such-string-ever-existed is not a filename (hence "it
cannot be a path, either"), another time to give "better diagnosis".

The thing is, the second time it runs, we already know that traversing the
history all the way down to the root will _not_ find any matching commit.

Rename misguided "gently" parameter, which is turned off _only_ when the
"detailed diagnosis" codepath knows that it cannot be a ref and making the
call only for the caller to die with a message.  Flip its meaning (and
adjust the callers) and call it "only_to_die", which is not a great name,
but it describes far more clearly what the codepaths that switches their
behaviour based on this variable do.

On my box, the command spends ~1.8 seconds without the patch to make the
report; with the patch it spends ~1.12 seconds.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We may want to give the pathspec subsystem such a feature, but not while
we are still using get_pathspec() that returns a stupid "char **" that
loses subtle nuances that existed in the input string.

In the meantime, the callers of get_pathspec() that want to support it
could do an equivalent before feeding their argv[] to the function
themselves quite easily.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This reverts commit d0546e2d, which
was only meant to be a Proof-of-concept used during the discussion.

The real implementation of the feature needs to wait until we migrate
all the code to use "struct pathspec", not "char **", to represent
richer semantics given to pathspec.

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The earlier design was to take whatever non-alnum that the short format
parser happens to support, leaving the rest as part of the pattern, so a
version of git that knows '*' magic and a version that does not would have
behaved differently when given ":*Makefile".  The former would have
applied the '*' magic to the pattern "Makefile", while the latter would
used no magic to the pattern "*Makefile".

Instead, just reserve all non-alnum ASCII letters that are neither glob
nor regexp special as potential magic signature, and when we see a magic
that is not supported, die with an error message, just like the longhand
codepath does.

With this, ":%#!*Makefile" will always mean "%#!" magic applied to the
pattern "*Makefile", no matter what version of git is used (it is a
different matter if the version of git supports all of these three magic
matching rules).

Also make ':' without anything else to mean "there is no pathspec".  This
would allow differences between "git log" and "git log ." run from the top
level of the working tree (the latter simplifies no-op commits away from
the history) to be expressed from a subdirectory by saying "git log :".
Helped-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Support ":/" magic string that can be prefixed to a pathspec element to
say "this names the path from the top-level of the working tree", when
you are in the subdirectory.

For example, you should be able to say:

    $ edit Makefile ;# top-level
    $ cd Documentation
    $ edit git.txt ;# in the subdirectory

and then do one of three things, still inside the subdirectory:

    $ git add -u .  ;# add only Documentation/git.txt
    $ git add -u :/ ;# add everything, including paths outside Documentation
    $ git add -u    ;# whatever the default setting is.

To truly support magic pathspec, the API needs to be restructured so that
get_pathspec() and init_pathspec() are unified into one call.  Currently,
the former just prefixes the user supplied pathspec with the current
subdirectory path, and the latter takes the output from the former and
pre-parses them into a bit richer structure for easier handling.  They
should become a single API function that takes the current subdirectory
path and the remainder of argv[] (after parsing --options and revision
arguments from the command line) and returns an array of parsed pathspec
elements, and "magic" should become attributes of struct pathspec_item.

This patch implements only "top" magic because it can be hacked into the
system without such a refactoring.

The syntax for magic pathspec prefix is designed to be extensible yet
simple to type to invoke a simple magic like "from the top".  The parser
for the magic prefix is hooked into get_pathspec() function in this patch,
and it needs to be moved when we refactor the API.

But we have to start from somewhere.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The same old problem reappears after setup code is reworked.  We tend
to assume there is at least one path component in a path and forget
that path can be simply '/'.
Reported-by: NMatthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.

The function calls have been replaced 1-to-1 in their usage.
Signed-off-by: NCarlos Martín Nieto <cmn@elego.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The original intention of --work-tree was to allow people to work in a
subdirectory of their working tree that does not have an embedded .git
directory.  Because their working tree, which their $cwd was in, did not
have an embedded .git, they needed to use $GIT_DIR to specify where it is,
and because this meant there was no way to discover where the root level
of the working tree was, so we needed to add $GIT_WORK_TREE to tell git
where it was.

However, this facility has long been (mis)used by people's scripts to
start git from a working tree _with_ an embedded .git directory, let git
find .git directory, and then pretend as if an unrelated directory were
the associated working tree of the .git directory found by the discovery
process.  It happens to work in simple cases, and is not worth causing
"regression" to these scripts.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

otherwise, comparison to validate against work tree will fail when
the path includes a symlink and the name passed is not canonical.
Signed-off-by: NCarlo Marcelo Arenas Belon <carenas@sajinet.com.pe>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When setup_work_tree() is called, it moves cwd to $GIT_WORK_TREE and
makes internal copy of $GIT_WORK_TREE absolute. The environt variable,
if set by user, remains unchanged. If the variable is relative, it is
no longer correct because its base dir has changed.

Instead of making $GIT_WORK_TREE absolute too, we just say "." and let
subsequent git processes handle it.
Reported-by: NMichel Briand <michelbriand@free.fr>
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function is the most complex one among the three setup_*
functions because all GIT_DIR, GIT_WORK_TREE, core.worktree and
core.bare are involved.

Because core.worktree is only effective inside
setup_explicit_git_dir() and the extra code in setup_git_directory()
is to handle that. The extra code can now be retired.

Also note that setup_explicit assignment is removed, worktree setting
is no longer decided by get_git_work_tree(). get_git_work_tree() will
be simplified in the next commit.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If core.bare is true, discard the discovered worktree, move back to
original cwd.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

work_tree_env argument is removed because this function does not need
it. GIT_WORK_TREE is only effective inside setup_explicit_git_dir.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

get_git_work_tree() takes input as core.worktree, core.bare,
GIT_WORK_TREE and decides correct worktree setting.

Unfortunately it does not do its job well. core.worktree and
GIT_WORK_TREE should only be taken into account, if GIT_DIR is set
(which is handled by setup_explicit_git_dir). For other setup cases,
only core.bare matters.

Add a temporary variable setup_explicit to adjust get_git_work_tree()
behavior as such. This variable will be gone once setup_* rework is
done.

Also remove is_bare_repository_cfg check in set_git_work_tree() to
ease the rework. We are going to check for core.bare and core.worktree
early before setting worktree. For example, if core.bare is true, no
need to set worktree.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When git_config() is called, either git_dir has already been set (by
$GIT_DIR env or set_git_dir()), or it will default git_dir to ".git".

git_config_early() gives setup functions more freedom because it does
not require git_dir. Give it a config path, it will happily examine
it.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

prefix_path() allocates new buffer. There's no reason for it to keep
the buffer for itself and waste memory.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Save the path from the original cwd to the cwd at the end of the
setup procedure in the startup_info struct introduced in e37c1329
(2010-08-05).  The value cannot vary from thread to thread anyway,
since the cwd is global.

So now in your builtin command, instead of passing prefix around,
when you want to convert a user-supplied path to a cwd-relative
path, you can use startup_info->prefix directly.

Caveat: As with the return value from setup_git_directory_gently(),
startup_info->prefix would be NULL when the original cwd is not a
subdir of the toplevel.

Longer term, this would allow the prefix to be reused when several
noncooperating functions require access to the same repository (for
example, when accessing configuration before running a builtin).
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Current prefix_filename() is proofed against the case where the prefix
'pfx' is NULL or a 0-length string, _except on Windows_.

Change the behaviour to work the same on both platforms, and only
check pfx_len so that callers passing a NULL prefix with a nonzero
pfx_len segfault early on both.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As v1.7.2~16^2 (git --paginate: paginate external commands
again, 2010-07-14) explains, builtins (like git config) that
do not use RUN_SETUP are not finding GIT_DIR set correctly when
it is time to launch the pager from run_builtin().  If they
were to search for a repository sooner, then the outcome of such
early repository accesses would be more predictable and reliable.

The cmd_*() functions learn whether a repository was found through the
*nongit_ok return value from setup_git_directory_gently().  If
run_builtin() is to take care of the repository search itself, that
datum needs to be retrievable from somewhere else.  Use the
startup_info struct for this.

As a bonus, this information becomes available to functions such as
git_config() which might want to avoid trying to access a repository
when none is present.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Finish the clean-up of setup_git_directory_gently() by splitting the
last case of validation+setup (global variables, prefix, check_format,
set_git_dir) into its own function.  Now setup_git_git_directory_gently
itself takes care of discovery only and the functions that pick up
from there are nearby in the source file so they can be easily
compared.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

v1.6.1.3~4^2 (Fix gitdir detection when in subdir of gitdir,
2009-01-16) did not go far enough: when a git directory is
an ancestor of the original working directory, not only
should GIT_DIR be set to point to the .git directory, but
the original working directory should be restored before
carrying out the relevant command.

This way, the effect of running a git command from a subdir
of .git will be the same whether or not GIT_DIR is explicitly
set.

Noticed while investigating v1.6.0.3~1 (rehabilitate 'git
index-pack' inside the object store, 2008-10-20).
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This does not eliminate any code, but it skims some off of
the main loop of setup_git_directory_gently so that can be
understood more easily.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Perhaps some day, other similar conditions (hitting the mount point,
hitting the root of the file system) will share this code.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a repository is found as an ancestor of the original
working directory, it is assumed by default to be bare.
Handle this case with its own function.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The repository discovery procedure looks something like this:

	while (same filesystem) {
		check .git in working dir
		check .
		chdir(..)
	}

Add a function for the first step to make the actual code look a bit
closer to that pseudocode.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If $GIT_DIR is set, setup_git_directory_gently does not have
to do any repository discovery at all.  Split off a function
for the validation it still does do, in the hope that this will
make setup_git_directory_gently proper less daunting to read.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This prevents a buffer overrun that could otherwise be triggered by
creating a file called '.git' with contents

  gitdir: (something really long)
Signed-off-by: NGreg Brockman <gdb@mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This prevents a buffer overrun that could otherwise be triggered by
creating a file called '.git' with contents

  gitdir: (something really long)
Signed-off-by: NGreg Brockman <gdb@mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The original declaration was int, which seems to cause trouble on my
machine.  It causes spurious "filesystem boundary" errors when running
the testsuite.  The cause seems to be

  $ stat -c%d .
  2147549952

which is too large for a 32-bit int type.

Using the correct type, dev_t, solves the issue.  (Because I'm
paranoid and forgetful, I checked -- yes, Unix v7 had dev_t.)

Other uses of st_dev seem to be reasonably safe.   fill_stat_cache_info
truncates it to an 'unsigned int', but that value seems to be used only
to validate the cache, and only if USE_STDEV is defined.
Signed-off-by: NRaja R Harinath <harinath@hurrynot.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a missing ONE_FILESYSTEM defaults to true, the only users who set this
variable set it to false to tell git not to limit the discovery to one
filesystem; there are too many negations in one sentence to make a simple
panda brain dizzy.

Use the variable GIT_DISCOVERY_ACROSS_FILESYSTEM that changes the
behaviour from the default "limit to one filesystem" to "cross the
boundary as I ask you to"; makes the semantics much more straight
forward.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Regarding the new environment variable, Linus Torvalds
<torvalds@linux-foundation.org> writes on Tue, 30 Mar 2010 in
<alpine.LFD.2.00.1003301537150.3707@i5.linux-foundation.org>:

    I suspect that it is _very_ unusual to have a source repo that crosses
    multiple filesystems, and the original reason for this patch-series
    seems to me to be likely to be more common than that multi-fs case. So
    having the logic go the other way would seem to match the common case,
    no?

The "crossing filesystem boundary" condition is checked by comparing
st_dev field in the result from stat(2).  This is slightly worrysome if
non-POSIX ports return different values in the field even for directories
in the same work tree extracted to the same "filesystem".  Erik Faye-Lund
confirms that in the msysgit port st_dev is 0, so this should be safe, as
"even Windows is safe" ;-)

This will affect those who use /.git to cram /etc and /home/me in the same
repostiory, /home is mounted from non-root filesystem, and a git operation
is done from inside /home/me/src.  But that is such a corner case we don't
want to give preference over helping people who will benefit from having
this default so that they do not have to suffer from slow automounters.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This patch makes git pay attention to the GIT_ONE_FILESYSTEM environment
variable. When that variable is set, git will stop searching for a
GIT_DIR when it attempts to cross a filesystem boundary.

When working in an environment with too many automount points to make
maintaining a GIT_CEILING_DIRECTORIES list enjoyable, GIT_ONE_FILESYSTEM
gives the option of turning all such attempts off with one setting.
Signed-off-by: NLars R. Damerow <lars@pixar.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Without this truncation the error message printed only shows the cwd
from the start of the search, not where it failed.
Signed-off-by: NLars R. Damerow <lars@pixar.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git should work regardless where the working directory is located,
even at root. This patch fixes two places where it assumes working
directory always have parent directory.

In setup_git_directory_gently(), when Git goes up to root and finds
.git there, it happily sets worktree to "" instead of "/".

In prefix_path(), loosen the outside repo check a little bit. Usually
when a path XXX is inside worktree /foo, it must be either "/foo", or
"/foo/...". When worktree is simply "/", we can safely ignore the
check: we have a slash at the beginning already.

Not related to worktree, but also set gitdir correctly if a bare repo
is placed (insanely?) at root.

Thanks João Carlos Mendes Luís for pointing out this problem.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>