Pushing a non-fast-forward update to a remote repository will result in
an error, but the hint text doesn't provide the correct resolution in
every case. Give better resolution advice in three push scenarios:

1) If you push your current branch and it triggers a non-fast-forward
error, you should merge remote changes with 'git pull' before pushing
again.

2) If you push to a shared repository others push to, and your local
tracking branches are not kept up to date, the 'matching refs' default
will generate non-fast-forward errors on outdated branches. If this is
your workflow, the 'matching refs' default is not for you. Consider
setting the 'push.default' configuration variable to 'current' or
'upstream' to ensure only your current branch is pushed.

3) If you explicitly specify a ref that is not your current branch or
push matching branches with ':', you will generate a non-fast-forward
error if any pushed branch tip is out of date. You should checkout the
offending branch and merge remote changes before pushing again.

Teach transport.c to recognize these scenarios and configure push.c
to hint for them. If 'git push's default behavior changes or we
discover more scenarios, extension is easy. Standardize on the
advice API and add three new advice variables, 'pushNonFFCurrent',
'pushNonFFDefault', and 'pushNonFFMatching'. Setting any of these
to 'false' will disable their affiliated advice. Setting
'pushNonFastForward' to false will disable all three, thus preserving the
config option for users who already set it, but guaranteeing new
users won't disable push advice accidentally.
Based-on-patch-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NChristopher Tiwald <christiwald@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In particular, sparse complains as follows:

        SP ctype.c
    ctype.c:30:12: warning: symbol 'tolower_trans_tbl' was not declared.\
         Should it be static?

An appropriate extern declaration for the 'tolower_trans_tbl' symbol
is included in the "cache.h" header file. In order to suppress the
warning, therefore, we could replace the "git-compat-util.h" header
inclusion with "cache.h", since "cache.h" includes "git-compat-util.h"
in turn. Here, however, we choose to move the extern declaration for
'tolower_trans_tbl' into "git-compat-util.h", alongside the other
extern declaration from ctype.c for 'sane_ctype'.
Signed-off-by: NRamsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

check_leading_path() and has_dirs_only_path() both always use the default
cache, which could be a caveat for adding parallelism (which is a concern
and even a GSoC proposal).

Reimplement these two in terms of new threaded_check_leading_path() and
threaded_has_dirs_only_path() that take their own copy of the cache.
Signed-off-by: NJared Hance <jaredhance@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In order to prepare the kwset machinery for a case-insensitive search, we
used to use a static table of 256 elements and filled it every time before
calling kwsalloc().  Because the kwset machinery will never modify this
table, just allocate a single instance globally and fill it at the compile
time.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It can be useful to split your ~/.gitconfig across multiple
files. For example, you might have a "main" file which is
used on many machines, but a small set of per-machine
tweaks. Or you may want to make some of your config public
(e.g., clever aliases) while keeping other data back (e.g.,
your name or other identifying information). Or you may want
to include a number of config options in some subset of your
repos without copying and pasting (e.g., you want to
reference them from the .git/config of participating repos).

This patch introduces an include directive for config files.
It looks like:

  [include]
    path = /path/to/file

This is syntactically backwards-compatible with existing git
config parsers (i.e., they will see it as another config
entry and ignore it unless you are looking up include.path).

The implementation provides a "git_config_include" callback
which wraps regular config callbacks. Callers can pass it to
git_config_from_file, and it will transparently follow any
include directives, passing all of the discovered options to
the real callback.

Include directives are turned on automatically for "regular"
git config parsing. This includes calls to git_config, as
well as calls to the "git config" program that do not
specify a single file (e.g., using "-f", "--global", etc).
They are not turned on in other cases, including:

  1. Parsing of other config-like files, like .gitmodules.
     There isn't a real need, and I'd rather be conservative
     and avoid unnecessary incompatibility or confusion.

  2. Reading single files via "git config". This is for two
     reasons:

       a. backwards compatibility with scripts looking at
          config-like files.

       b. inspection of a specific file probably means you
	  care about just what's in that file, not a general
          lookup for "do we have this value anywhere at
	  all". If that is not the case, the caller can
	  always specify "--includes".

  3. Writing files via "git config"; we want to treat
     include.* variables as literal items to be copied (or
     modified), and not expand them. So "git config
     --unset-all foo.bar" would operate _only_ on
     .git/config, not any of its included files (just as it
     also does not operate on ~/.gitconfig).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is a magic global variable that was intended as an
override to the usual git-config lookup process. Once upon a
time, you could specify GIT_CONFIG to any git program, and
it would look only at that file. This turned out to be
confusing and cause a lot of bugs for little gain. As a
result, dc871831 (Only use GIT_CONFIG in "git config", not
other programs, 2008-06-30) took this away for all callers
except git-config.

Since git-config no longer uses it either, the variable can
just go away. As the diff shows, nobody was setting to
anything except NULL, so we can just replace any sites where
it was read with NULL.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Callers may want to provide a specific version of a file in which to look
for config. Right now this can be done by setting the magic global
config_exclusive_filename variable.  By providing a version of git_config
that takes a filename, we can take a step towards making this magic global
go away.

Furthermore, by providing a more "advanced" interface, we now have a a
natural place to add new options for callers like git-config, which care
about tweaking the specifics of config lookup, without disturbing the
large number of "simple" users (i.e., every other part of git).

The astute reader of this patch may notice that the logic for handling
config_exclusive_filename was taken out of git_config_early, but added
into git_config. This means that git_config_early will no longer respect
config_exclusive_filename.  That's OK, because the only other caller of
git_config_early is check_repository_format_gently, but the only function
which sets config_exclusive_filename is cmd_config, which does not call
check_repository_format_gently (and if it did, it would have been a bug,
anyway, as we would be checking the repository format in the wrong file).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The other config-writing functions (git_config_set and
git_config_set_multivar) each have an -"in_file" version to
write a specific file. Let's add one for rename_section,
with the eventual goal of moving away from the magic
config_exclusive_filename global.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/blame.c has a helper function to compute how many columns
we need to show a line-number, whose implementation is reusable as
a more generic helper function to count the number of columns
necessary to show any cardinal number.

Rename it to decimal_width(), move it to pager.c and export it for
use by future callers.
Signed-off-by: NZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

term_columns() checks for terminal width via ioctl(2) on the standard
output, but we spawn the pager too early for this check to be useful.

The effect of this buglet can be observed by opening a wide terminal and
running "git -p help --all", which still shows 80-column output, while
"git help --all" uses the full terminal width. Run the check before we
spawn the pager to fix this.

While at it, move term_columns() to pager.c and export it from cache.h so
that callers other than the help subsystem can use it.
Signed-off-by: NZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When you specify a local repository on the command line of
clone, ls-remote, upload-pack, receive-pack, or upload-archive,
or in a request to git-daemon, we perform a little bit of
lookup magic, doing things like looking in working trees for
.git directories and appending ".git" for bare repos.

For clone, this magic happens in get_repo_path. For
everything else, it happens in enter_repo. In both cases,
there are some ambiguous or confusing cases that aren't
handled well, and there is one case that is not handled the
same by both methods.

This patch tries to provide (and test!) standard, sensible
lookup rules for both code paths. The intended changes are:

  1. When looking up "foo", we have always preferred
     a working tree "foo" (containing "foo/.git" over the
     bare "foo.git". But we did not prefer a bare "foo" over
     "foo.git". With this patch, we do so.

  2. We would select directories that existed but didn't
     actually look like git repositories. With this patch,
     we make sure a selected directory looks like a git
     repo. Not only is this more sensible in general, but it
     will help anybody who is negatively affected by change
     (1) negatively (e.g., if they had "foo.git" next to its
     separate work tree "foo", and expect to keep finding
     "foo.git" when they reference "foo").

  3. The enter_repo code path would, given "foo", look for
     "foo.git/.git" (i.e., do the ".git" append magic even
     for a repo with working tree). The clone code path did
     not; with this patch, they now behave the same.

In the unlikely case of a working tree overlaying a bare
repo (i.e., a ".git" directory _inside_ a bare repo), we
continue to treat it as a working tree (prefering the
"inner" .git over the bare repo). This is mainly because the
combination seems nonsensical, and I'd rather stick with
existing behavior on the off chance that somebody is relying
on it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We have been carefully choosing feature names used in the protocol
extensions so that the vocabulary does not contain a word that is a
substring of another word, so it is not a real problem, but we have
recently added "quiet" feature word, which would mean we cannot later
add some other word with "quiet" (e.g. "quiet-push"), which is awkward.

Let's make sure that we can eventually be able to do so by teaching the
clients and servers that feature words consist of non whitespace
letters. This parser also allows us to later add features with parameters
e.g. "feature=1.5" (parameter values need to be quoted for whitespaces,
but we will worry about the detauls when we do introduce them).
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>

This function was used for comparing local and remote ref
names during fetch (which makes it a candidate for "most
confusingly named function of the year").

It no longer has any callers, so let's get rid of it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The get_remote_heads function reads the list of remote refs
during git protocol session. It dates all the way back to
def88e9a (Commit first cut at "git-fetch-pack", 2005-07-04).
At that time, the idea was to come up with a list of refs we
were interested in, and then filter the list as we got it
from the remote side.

Later, 1baaae5e (Make maximal use of the remote refs,
2005-10-28) stopped filtering at the get_remote_heads layer,
letting us use the non-matching refs to find common history.

As a result, all callers now simply pass an empty match
list (and any future callers will want to do the same). So
let's drop these now-useless parameters.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

resolve_ref() may return a pointer to a shared buffer and can be
overwritten by the next resolve_ref() calls. Callers need to
pay attention, not to keep the pointer when the next call happens.

Rename with "_unsafe" suffix to warn developers (or reviewers) before
introducing new call sites.

This patch is generated using the following command

git grep -l 'resolve_ref(' -- '*.[ch]'|xargs sed -i 's/resolve_ref(/resolve_ref_unsafe(/g'
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is currently in connect.c, but really has nothing to
do with the git protocol itself. Let's make a new source
file all about prompting the user, which will make it
cleaner to refactor.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Try to consistently use the variable name "refname" when referring to
a string that names a reference.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This extends the earlier approach to stream a large file directly from the
filesystem to its own packfile, and allows "git add" to send large files
directly into a single pack. Older code used to spawn fast-import, but the
new bulk-checkin API replaces it.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

resolve_ref() may return a pointer to a static buffer, which is not
safe for long-term use because if another resolve_ref() call happens,
the buffer may be changed.  Many call sites though do not care about
this buffer. They simply check if the return value is NULL or not.

Convert all these call sites to new wrappers to reduce resolve_ref()
calls from 57 to 34. If we change resolve_ref() prototype later on
to avoid passing static buffer out, this helps reduce changes.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git log frotz" can DWIM to "refs/remotes/frotz/HEAD", but in the remote
access context, "git fetch frotz" to fetch what the other side happened to
have fetched from what it calls 'frotz' (which may not have any relation
to what we consider is 'frotz') the last time would not make much sense,
so the fetch rules table did not include "refs/remotes/%.*s/HEAD".

When the user really wants to, "git fetch $there remotes/frotz/HEAD" would
let her do so anyway, so this is not about safety or security; it merely
is about confusion avoidance and discouraging meaningless usage.

Specifically, it is _not_ about ambiguity avoidance. A name that would
become ambiguous if we use the same rules table for both fetch and local
rev-parse would be ambiguous locally at the remote side.

So for the same reason as we added rule to allow "git fetch $there v1.0"
instead of "git fetch $there tags/v1.0" in the previous commit, here is a
bit longer rope for the users, which incidentally simplifies our code.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since in-memory index entries are allocated individually now, the
variable slack at the end meant to provide an eight byte alignment
is not needed anymore.  Have a single NUL instead.  This saves zero
to seven bytes for an entry, depending on its filename length.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The code to estimate the in-memory size of the index based on its on-disk
representation is subtly wrong for certain architecture-dependent struct
layouts.  Instead of fixing it, replace the code to keep the index entries
in a single large block of memory and allocate each entry separately
instead.  This is both simpler and more flexible, as individual entries
can now be freed.  Actually using that added flexibility is left for a
later patch.
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's possible that while pack-objects is running, a
simultaneously running prune process might delete a pack
that we are interested in. Because we load the pack indices
early on, we know that the pack contains our item, but by
the time we try to open and map it, it is gone.

Since c715f783, we already protect against this in the normal
object access code path, but pack-objects accesses the packs
at a lower level.  In the normal access path, we call
find_pack_entry, which will call find_pack_entry_one on each
pack index, which does the actual lookup. If it gets a hit,
we will actually open and verify the validity of the
matching packfile (using c715f783's is_pack_valid). If we
can't open it, we'll issue a warning and pretend that we
didn't find it, causing us to go on to the next pack (or on
to loose objects).

Furthermore, we will cache the descriptor to the opened
packfile. Which means that later, when we actually try to
access the object, we are likely to still have that packfile
opened, and won't care if it has been unlinked from the
filesystem.

Notice the "likely" above. If there is another pack access
in the interim, and we run out of descriptors, we could
close the pack. And then a later attempt to access the
closed pack could fail (we'll try to re-open it, of course,
but it may have been deleted). In practice, this doesn't
happen because we tend to look up items and then access them
immediately.

Pack-objects does not follow this code path. Instead, it
accesses the packs at a much lower level, using
find_pack_entry_one directly. This means we skip the
is_pack_valid check, and may end up with the name of a
packfile, but no open descriptor.

We can add the same is_pack_valid check here. Unfortunately,
the access patterns of pack-objects are not quite as nice
for keeping lookup and object access together. We look up
each object as we find out about it, and the only later when
writing the packfile do we necessarily access it. Which
means that the opened packfile may be closed in the interim.

In practice, however, adding this check still has value, for
three reasons.

  1. If you have a reasonable number of packs and/or a
     reasonable file descriptor limit, you can keep all of
     your packs open simultaneously. If this is the case,
     then the race is impossible to trigger.

  2. Even if you can't keep all packs open at once, you
     may end up keeping the deleted one open (i.e., you may
     get lucky).

  3. The race window is shortened. You may notice early that
     the pack is gone, and not try to access it. Triggering
     the problem without this check means deleting the pack
     any time after we read the list of index files, but
     before we access the looked-up objects.  Triggering it
     with this check means deleting the pack means deleting
     the pack after we do a lookup (and successfully access
     the packfile), but before we access the object. Which
     is a smaller window.
Acked-by: NNicolas Pitre <nico@fluxnic.net>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When core.ignorecase is turned on and there are stale index
entries, "git commit" can sometimes report directories as
untracked, even though they contain tracked files.

You can see an example of this with:

    # make a case-insensitive repo
    git init repo && cd repo &&
    git config core.ignorecase true &&

    # with some tracked files in a subdir
    mkdir subdir &&
    > subdir/one &&
    > subdir/two &&
    git add . &&
    git commit -m base &&

    # now make the index entries stale
    touch subdir/* &&

    # and then ask commit to update those entries and show
    # us the status template
    git commit -a

which will report "subdir/"  as untracked, even though it
clearly contains two tracked files. What is happening in the
commit program is this:

  1. We load the index, and for each entry, insert it into the index's
     name_hash. In addition, if ignorecase is turned on, we make an
     entry in the name_hash for the directory (e.g., "contrib/"), which
     uses the following code from 5102c617's hash_index_entry_directories:

        hash = hash_name(ce->name, ptr - ce->name);
        if (!lookup_hash(hash, &istate->name_hash)) {
                pos = insert_hash(hash, &istate->name_hash);
		if (pos) {
			ce->next = *pos;
			*pos = ce;
		}
        }

     Note that we only add the directory entry if there is not already an
     entry.

  2. We run add_files_to_cache, which gets updated information for each
     cache entry. It helpfully inserts this information into the cache,
     which calls replace_index_entry. This in turn calls
     remove_name_hash() on the old entry, and add_name_hash() on the new
     one. But remove_name_hash doesn't actually remove from the hash, it
     only marks it as "no longer interesting" (from cache.h):

      /*
       * We don't actually *remove* it, we can just mark it invalid so that
       * we won't find it in lookups.
       *
       * Not only would we have to search the lists (simple enough), but
       * we'd also have to rehash other hash buckets in case this makes the
       * hash bucket empty (common). So it's much better to just mark
       * it.
       */
      static inline void remove_name_hash(struct cache_entry *ce)
      {
              ce->ce_flags |= CE_UNHASHED;
      }

     This is OK in the specific-file case, since the entries in the hash
     form a linked list, and we can just skip the "not here anymore"
     entries during lookup.

     But for the directory hash entry, we will _not_ write a new entry,
     because there is already one there: the old one that is actually no
     longer interesting!

  3. While traversing the directories, we end up in the
     directory_exists_in_index_icase function to see if a directory is
     interesting. This in turn checks index_name_exists, which will
     look up the directory in the index's name_hash. We see the old,
     deleted record, and assume there is nothing interesting. The
     directory gets marked as untracked, even though there are index
     entries in it.

The problem is in the code I showed above:

        hash = hash_name(ce->name, ptr - ce->name);
        if (!lookup_hash(hash, &istate->name_hash)) {
                pos = insert_hash(hash, &istate->name_hash);
		if (pos) {
			ce->next = *pos;
			*pos = ce;
		}
        }

Having a single cache entry that represents the directory is
not enough; that entry may go away if the index is changed.
It may be tempting to say that the problem is in our removal
method; if we removed the entry entirely instead of simply
marking it as "not here anymore", then we would know we need
to insert a new entry. But that only covers this particular
case of remove-replace. In the more general case, consider
something like this:

  1. We add "foo/bar" and "foo/baz" to the index. Each gets
     their own entry in name_hash, plus we make a "foo/"
     entry that points to "foo/bar".

  2. We remove the "foo/bar" entry from the index, and from
     the name_hash.

  3. We ask if "foo/" exists, and see no entry, even though
     "foo/baz" exists.

So we need that directory entry to have the list of _all_
cache entries that indicate that the directory is tracked.
So that implies making a linked list as we do for other
entries, like:

  hash = hash_name(ce->name, ptr - ce->name);
  pos = insert_hash(hash, &istate->name_hash);
  if (pos) {
	  ce->next = *pos;
	  *pos = ce;
  }

But that's not right either. In fact, it shows a second bug
in the current code, which is that the "ce->next" pointer is
supposed to be linking entries for a specific filename
entry, but here we are overwriting it for the directory
entry. So the same cache entry ends up in two linked lists,
but they share the same "next" pointer.

As it turns out, this second bug can't be triggered in the
current code. The "if (pos)" conditional is totally dead
code; pos will only be non-NULL if there was an existing
hash entry, and we already checked that there wasn't one
through our call to lookup_hash.

But fixing the first bug means taking out that call to
lookup_hash, which is going to activate the buggy dead code,
and we'll end up splicing the two linked lists together.

So we need to have a separate next pointer for the list in
the directory bucket, and we need to traverse that list in
index_name_exists when we are looking up a directory.

This bloats "struct cache_entry" by a few bytes. Which is
annoying, because it's only necessary when core.ignorecase
is enabled. There's not an easy way around it, short of
separating out the "next" pointers from cache_entry entirely
(i.e., having a separate "cache_entry_list" struct that gets
stored in the name_hash). In practice, it probably doesn't
matter; we have thousands of cache entries, compared to the
millions of objects (where adding 4 bytes to the struct
actually does impact performance).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This code calls git_config from a helper function to parse the config entry
it is interested in.  Calling git_config in this way may cause a problem if
the helper function can be called after a previous call to git_config by
another function since the second call to git_config may reset some
variable to the value in the config file which was previously overridden.

The above is not a problem in this case since the function passed to
git_config only parses one config entry and the variable it sets is not
assigned outside of the parsing function.  But a programmer who desires
all of the standard config options to be parsed may be tempted to modify
git_attr_config() so that it falls back to git_default_config() and then it
_would_ be vulnerable to the above described behavior.

So, move the call to git_config up into the top-level cmd_* function and
move the responsibility for parsing core.attributesfile into the main
config file parser.

Which is only the logical thing to do ;-)
Signed-off-by: NBrandon Casey <drafnel@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Record information about resolve_ref(), hard-won via reverse
engineering, in a comment for future spelunkers.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Previously, get_sha1_hex() would read one character past the end of a
null-terminated string whose strlen was an even number less than 40.
Although the function correctly returned -1 in these cases, the extra
memory access might have been to uninitialized (or even, conceivably,
unallocated) memory.

Add a check to avoid reading past the end of a string.

This problem was discovered by Thomas Rast <trast@student.ethz.ch>
using valgrind.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

entr_repo(..., 0) currently modifies the input to strip away
trailing slashes. This means that we some times need to copy the
input to keep the original.

Change it to unconditionally copy it into the used_path buffer so
we can safely use the input without having to copy it. Also store
a working copy in validated_path up-front before we start
resolving anything.
Signed-off-by: NErik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: NPhil Hord <hordp@cisco.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Also make common_prefix_len() static as this refactoring makes dir.c
itself the only caller of this helper function.
Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Passing a prefix to a function that is supposed to find the prefix is
strange. And it's really only used if the pathspec is NULL. Make the
callers handle this case instead.

As we are always returning a fresh copy of a string (or NULL), change the
type of the returned value to non-const "char *".
Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The function was not gentle at all to the callers and died without giving
them a chance to deal with possible errors. Rename it to read_gitfile(),
and update all the callers.

As no existing caller needs a true "gently" variant, we do not bother
adding one at this point.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Check if <path> is a valid git-dir or a valid git-file that points
to a valid git-dir.

We want tests to be independent from the fact that a git-dir may
be a git-file. Thus we changed tests to use this feature.
Signed-off-by: NFredrik Gustafsson <iveqy@iveqy.com>
Mentored-by: NJens Lehmann <Jens.Lehmann@web.de>
Mentored-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The following sequence of commands reveals an issue with error
reporting of relative paths:

 $ mkdir sub
 $ cd sub
 $ git ls-files --error-unmatch ../bbbbb
 error: pathspec 'b' did not match any file(s) known to git.
 $ git commit --error-unmatch ../bbbbb
 error: pathspec 'b' did not match any file(s) known to git.

This bug is visible only if the normalized path (i.e., the relative
path from the repository root) is longer than the prefix.
Otherwise, the code skips over the normalized path and reads from
an unused memory location which still contains a leftover of the
original command line argument.

So instead, use the existing facilities to deal with relative paths
correctly.

Also fix inconsistency between "checkout" and "commit", e.g.

    $ cd Documentation
    $ git checkout nosuch.txt
    error: pathspec 'Documentation/nosuch.txt' did not match...
    $ git commit nosuch.txt
    error: pathspec 'nosuch.txt' did not match...

by propagating the prefix down the codepath that reports the error.
Signed-off-by: NClemens Buchacher <drizzd@aon.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Introduce two new functions corresponding to "git_config_set" and
"git_config_set_multivar" to write a non-standard configuration file.
Expose these new functions in cache.h for other git programs to use.
Helped-by: NJeff King <peff@peff.net>
Helped-by: NJonathan Nieder <jrnieder@gmail.com>
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NRamkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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>

In a workload other than "git log" (without pathspec nor any option that
causes us to inspect trees and blobs), the recency pack order is said to
cause the access jump around quite a bit. Add a hook to allow us observe
how bad it is.

"git config core.logpackaccess /var/tmp/pal.txt" will give you the log
in the specified file.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add support for dividing the refs of a single repository into multiple
namespaces, each of which can have its own branches, tags, and HEAD.
Git can expose each namespace as an independent repository to pull from
and push to, while sharing the object store, and exposing all the refs
to operations such as git-gc.

Storing multiple repositories as namespaces of a single repository
avoids storing duplicate copies of the same objects, such as when
storing multiple branches of the same source.  The alternates mechanism
provides similar support for avoiding duplicates, but alternates do not
prevent duplication between new objects added to the repositories
without ongoing maintenance, while namespaces do.

To specify a namespace, set the GIT_NAMESPACE environment variable to
the namespace.  For each ref namespace, git stores the corresponding
refs in a directory under refs/namespaces/.  For example,
GIT_NAMESPACE=foo will store refs under refs/namespaces/foo/.  You can
also specify namespaces via the --namespace option to git.

Note that namespaces which include a / will expand to a hierarchy of
namespaces; for example, GIT_NAMESPACE=foo/bar will store refs under
refs/namespaces/foo/refs/namespaces/bar/.  This makes paths in
GIT_NAMESPACE behave hierarchically, so that cloning with
GIT_NAMESPACE=foo/bar produces the same result as cloning with
GIT_NAMESPACE=foo and cloning from that repo with GIT_NAMESPACE=bar.  It
also avoids ambiguity with strange namespace paths such as
foo/refs/heads/, which could otherwise generate directory/file conflicts
within the refs directory.

Add the infrastructure for ref namespaces: handle the GIT_NAMESPACE
environment variable and --namespace option, and support iterating over
refs in a namespace.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NJamey Sharp <jamey@minilop.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We use this internally to parse "git -c core.foo=bar", but
the general format of "key=value" is useful for other
places.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The size of objects we read from the repository and data we try to put
into the repository are represented in "unsigned long", so that on larger
architectures we can handle objects that weigh more than 4GB.

But the interface defined in zlib.h to communicate with inflate/deflate
limits avail_in (how many bytes of input are we calling zlib with) and
avail_out (how many bytes of output from zlib are we ready to accept)
fields effectively to 4GB by defining their type to be uInt.

In many places in our code, we allocate a large buffer (e.g. mmap'ing a
large loose object file) and tell zlib its size by assigning the size to
avail_in field of the stream, but that will truncate the high octets of
the real size. The worst part of this story is that we often pass around
z_stream (the state object used by zlib) to keep track of the number of
used bytes in input/output buffer by inspecting these two fields, which
practically limits our callchain to the same 4GB limit.

Wrap z_stream in another structure git_zstream that can express avail_in
and avail_out in unsigned long. For now, just die() when the caller gives
a size that cannot be given to a single zlib call. In later patches in the
series, we would make git_inflate() and git_deflate() internally loop to
give callers an illusion that our "improved" version of zlib interface can
operate on a buffer larger than 4GB in one go.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>