Older versions of pack-refs did not write peel lines for
refs outside of refs/tags. This meant that on reading the
pack-refs file, we might set the REF_KNOWS_PEELED flag for
such a ref, even though we do not know anything about its
peeled value.
The previous commit updated the writer to always peel, no
matter what the ref is. That means that packed-refs files
written by newer versions of git are fine to be read by both
old and new versions of git. However, we still have the
problem of reading packed-refs files written by older
versions of git, or by other implementations which have not
yet learned the same trick.
The simplest fix would be to always unset the
REF_KNOWS_PEELED flag for refs outside of refs/tags that do
not have a peel line (if it has a peel line, we know it is
valid, but we cannot assume a missing peel line means
anything). But that loses an important optimization, as
upload-pack should not need to load the object pointed to by
refs/heads/foo to determine that it is not a tag.
Instead, we add a "fully-peeled" trait to the packed-refs
file. If it is set, we know that we can trust a missing peel
line to mean that a ref cannot be peeled. Otherwise, we fall
back to assuming nothing.
[commit message and tests by Jeff King <peff@peff.net>]
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Syntax branchname@{upstream} should interpret its argument as a name of
a branch. Add the test to check that it doesn't try to interpret it as a
refname if the branch in question does not exist.
Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fast-export wants to export a blob object, it first
calls parse_object to get a "struct object" and check
whether we have already shown the object. If we haven't
shown it, we then use read_sha1_file to pull it from disk
and write it out.
That means we load each blob from disk twice: once for
parse_object to find its type and check its sha1, and a
second time when we actually output it. We can drop this to
a single load by using lookup_object to check the SHOWN
flag, and then checking the signature on and outputting a
single buffer.
This provides modest speedups on git.git (best-of-five, "git
fast-export HEAD >/dev/null"):
[before] [after]
real 0m14.347s real 0m13.780s
user 0m14.084s user 0m13.620s
sys 0m0.208s sys 0m0.100s
and somewhat more on more blob-heavy repos (this is a
repository full of media files):
[before] [after]
real 0m52.236s real 0m44.451s
user 0m50.568s user 0m43.000s
sys 0m1.536s sys 0m1.284s
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The handle_object function is rather vaguely named; it only
operates on blobs, and its purpose is to export the blob to
the output stream. Let's call it "export_blob" to make it
more clear what it does.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we pack an annotated tag ref, we write not only the
sha1 of the tag object along with the ref, but also the sha1
obtained by peeling the tag. This lets readers of the
pack-refs file know the peeled value without having to
actually load the object, speeding up upload-pack's ref
advertisement.
The writer marks a packed-refs file with peeled refs using
the "peeled" trait at the top of the file. When the reader
sees this trait, it knows that each ref is either followed
by its peeled value, or it is not an annotated tag.
However, there is a mismatch between the assumptions of the
reader and writer. The writer will only peel refs under
refs/tags, but the reader does not know this; it will assume
a ref without a peeled value must not be a tag object. Thus
an annotated tag object placed outside of the refs/tags
hierarchy will not have its peeled value printed by
upload-pack.
The simplest way to fix this is to start writing peel values
for all refs. This matches what the reader expects for both
new and old versions of git.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some call-sites do:
o = parse_object(sha1);
if (!o)
die("bad object %s", some_name);
We can now handle that as a one-liner, and get more
consistent output.
In the third case of this patch, it looks like we are losing
information, as the existing message also outputs the sha1
hex; however, parse_object will already have written a more
specific complaint about the sha1, so there is no point in
repeating it here.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many call-sites of parse_object assume that they will get a
non-NULL return value; this is not the case if we encounter
an error while parsing the object.
This patch adds a wrapper function around parse_object that
handles dying automatically, and uses it anywhere we
immediately try to access the return value as a non-NULL
pointer (i.e., anywhere that we would currently segfault).
This wrapper may also be useful in other places. The most
obvious one is code like:
o = parse_object(sha1);
if (!o)
die(...);
However, these should not be mechanically converted to
parse_object_or_die, as the die message is sometimes
customized. Later patches can address these sites on a
case-by-case basis.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint:
rev-parse: clarify documentation of $name@{upstream} syntax
sha1_name: pass object name length to diagnose_invalid_sha1_path()
Makefile: keep LIB_H entries together and sorted
"git rev-parse" interprets string in string@{upstream} as a name of
a branch not a ref. For example, refs/heads/master@{upstream} looks
for an upstream branch that is merged by git-pull to ref
refs/heads/refs/heads/master not to refs/heads/master.
However the documentation could mislead a user to believe that the
string is interpreted as ref.
Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The only caller of diagnose_invalid_sha1_path() extracts a substring from
an object name by creating a NUL-terminated copy of the interesting part.
Add a length parameter to the function and thus avoid the need for an
allocation, thereby simplifying the code.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git pull passed -q and -v only to git merge, but they can be useful for
git rebase as well, so pass them there, too.
In particular, using -q shuts up the "Already up-to-date." message.
Especially, a new test script runs the same "pull --rebase" twice to
make sure both cases are quiet, when it has something to fetch and
when it is already up to date.
Signed-off-by: Peter Eisentraut <peter@eisentraut.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This avoids unnecessary re-allocations and reinsertions. On webkit.git
(i.e. about 182k inserts to the name hash table), this reduces about
100ms out of 3s user time.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a follow-up to 60d24dd25 (Makefile: fold XDIFF_H and VCSSVN_H into
LIB_H), let the unconditional additions to LIB_H form a single sorted
list. Also drop the duplicate entry for xdiff/xdiff.h, which was easy
to spot after sorting.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is a long-time security feature that upload-pack will not
serve any "want" lines that do not correspond to the tip of
one of our refs. Traditionally, this was enforced by
checking the objects in the in-memory hash; they should have
been loaded and received the OUR_REF flag during the
advertisement.
The stateless-rpc mode, however, has a race condition here:
one process advertises, and another receives the want lines,
so the refs may have changed in the interim. To address
this, commit 051e400 added a new verification mode; if the
object is not OUR_REF, we set a "has_non_tip" flag, and then
later verify that the requested objects are reachable from
our current tips.
However, we still die immediately when the object is not in
our in-memory hash, and at this point we should only have
loaded our tip objects. So the check_non_tip code path does
not ever actually trigger, as any non-tip objects would
have already caused us to die.
We can fix that by using parse_object instead of
lookup_object, which will load the object from disk if it
has not already been loaded.
We still need to check that parse_object does not return
NULL, though, as it is possible we do not have the object
at all. A more appropriate error message would be "no such
object" rather than "not our ref"; however, we do not want
to leak information about what objects are or are not in
the object database, so we continue to use the same "not
our ref" message that would be produced by an unreachable
object.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack receives a "want" line from the client, it
adds it to an object array. We call lookup_object to find
the actual object, which will only check for objects already
in memory. This works because we are expecting to find
objects that we already loaded during the ref advertisement.
We use the resulting object structs for a variety of
purposes. Some of them care only about the object flags, but
others care about the type of the object (e.g.,
ok_to_give_up), or even feed them to the revision parser
(when --depth is used), which assumes that objects it
receives are fully parsed.
Once upon a time, this was OK; any object we loaded into
memory would also have been parsed. But since 435c833
(upload-pack: use peel_ref for ref advertisements,
2012-10-04), we try to avoid parsing objects during the ref
advertisement. This means that lookup_object may return an
object with a type of OBJ_NONE. The resulting mess depends
on the exact set of objects, but can include the revision
parser barfing, or the shallow code sending the wrong set of
objects.
This patch teaches upload-pack to parse each "want" object
as we receive it. We do not replace the lookup_object call
with parse_object, as the current code is careful not to let
just any object appear on a "want" line, but rather only one
we have previously advertised (whereas parse_object would
actually load any arbitrary object from disk).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we receive a "have" line from the client, we want to
load the object pointed to by the sha1. However, we are
careful to do:
o = lookup_object(sha1);
if (!o || !o->parsed)
o = parse_object(sha1);
to avoid loading the object from disk if we have already
seen it. However, since ccdc603 (parse_object: try internal
cache before reading object db), parse_object already does
this optimization internally. We can just call parse_object
directly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The translation of "completed with %d local objects" is put in a
48-byte buffer, which may be enough for English but not true for any
translations. Convert it to use strbuf (i.e. no hard limit on
translation length).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce advice.statusUoption to suggest considering use of -u to
strike different trade-off when it took more than 2 seconds to
enumerate untracked/ignored files.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In some repostories users experience that "git status" command takes
long time. The command spends some time searching the file system
for untracked files.
Explain the trade-off struck by the default choice of `normal` to
help users make an appropriate choice better, before talking about
the configuration variable.
Inspired by Torsten Bögershausen.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous code did not diagnose an incorrectly spelled ":(top"
as an error.
Signed-off-by: Andrew Wong <andrew.kw.w@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code assumes that the string ends at either `)` or `,`, and does
not handle the case where strcspn() returns length due to end of
string. So specifying ":(top" as pathspec will cause the loop to go
past the end of string.
Signed-off-by: Andrew Wong <andrew.kw.w@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This behavior is due to change in the future, but let's test
it anyway. That helps make sure we do not accidentally
switch the behavior too soon while we are working in the
area, and it means that we can easily verify the change when
we do make it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Originally, with no base, Git gave P4Merge $LOCAL as a dummy base:
p4merge "$LOCAL" "$LOCAL" "$REMOTE" "$MERGED"
Commit 0a0ec7bd changed this to:
p4merge "empty file" "$LOCAL" "$REMOTE" "$MERGED"
to avoid the problem of being unable to save in some circumstances with
similar inputs.
Unfortunately this approach produces much worse results on differing
inputs. P4Merge really regards the blank file as the base, and once you
have just a couple of differences between the two branches you end up
with one a massive full-file conflict. The 3-way diff is not readable,
and you have to invoke "difftool MERGE_HEAD HEAD" manually to get a
useful view.
The original approach appears to have invoked special 2-way merge
behaviour in P4Merge that occurs only if the base filename is "" or
equal to the left input. You get a good visual comparison, and it does
not auto-resolve differences. (Normally if one branch matched the base,
it would autoresolve to the other branch).
But there appears to be no way of getting this 2-way behaviour and being
able to reliably save. Having base==left appears to be triggering other
assumptions. There are tricks the user can use to force the save icon
on, but it's not intuitive.
So we now follow a suggestion given in the original patch's discussion:
generate a virtual base, consisting of the lines common to the two
branches. This is the same as the technique used in resolve and octopus
merges, so we relocate that code to a shared function.
Note that if there are no differences at the same location, this
technique can lead to automatic resolution without conflict, combining
everything from the 2 files. As with the other merges using this
technique, we assume the user will inspect the result before saving.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Reviewed-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reverse LOCAL and REMOTE when invoking P4Merge as a mergetool, so that
the incoming branch is now in the left-hand, blue triangle pane, and the
current branch is in the right-hand, green circle pane.
This change makes use of P4Merge consistent with its built-in help, its
reference documentation, and Perforce itself. But most importantly, it
makes merge results clearer. P4Merge is not totally symmetrical between
left and right; despite changing a few text labels from "theirs/ours" to
"left/right" when invoked manually, it still retains its original
Perforce "theirs/ours" viewpoint.
Most obviously, in the result pane P4Merge shows changes that are common
to both branches in green. This is on the basis of the current branch
being green, as it is when invoked from Perforce; it means that lines in
the result are blue if and only if they are being changed by the merge,
making the resulting diff clearer.
Note that P4Merge now shows "ours" on the right for both diff and merge,
unlike other diff/mergetools, which always have REMOTE on the right.
But observe that REMOTE is the working tree (ie "ours") for a diff,
while it's another branch (ie "theirs") for a merge.
Ours and theirs are reversed for a rebase - see "git help rebase".
However, this does produce the desired "show the results of this commit"
effect in P4Merge - changes that remain in the rebased commit (in your
branch, but not in the new base) appear in blue; changes that do not
appear in the rebased commit (from the new base, or common to both) are
in green. If Perforce had rebase, they'd probably not swap ours/theirs,
but make P4Merge show common changes in blue, picking out our changes in
green. We can't do that, so this is next best.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Reviewed-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git tag --force" mentions what old tag object is being replaced
when it is used to update an existing tag, but it shows the same
message when creating a new one. Stop doing that, as it does not
add any information.
Add a test for this and also to ensure --force can replace tags at
all.
Signed-off-by: Phil Hord <hordp@cisco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The generic chdir() helper sets the PWD environment
variable, as that is what is used by p4 to know its
current working directory. Normally the shell would
do this, but in git-p4, we must do it by hand.
However, when the path contains a symbolic link,
os.getcwd() will return the physical location. If the
p4 client specification includes symlinks, setting PWD
to the physical location causes p4 to think it is not
inside the client workspace. It complains, e.g.
Path /vol/bar/projects/foo/... is not under client root /p/foo
One workaround is to use AltRoots in the p4 client specification,
but it is cleaner to handle it directly in git-p4.
Other uses of chdir still require setting PWD to an
absolute path so p4 features like P4CONFIG work. See
bf1d68f (git-p4: use absolute directory for PWD env
var, 2011-12-09).
[ pw: tweak patch and commit message ]
Thanks-to: John Keeping <john@keeping.me.uk>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This test fails when the p4 client root includes
a symlink. It complains:
Path /vol/bar/projects/foo/... is not under client root /p/foo
and dumps a traceback.
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reorder option list in command-line usage to match the manual page.
Also make it less than 80-characters wide.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A recent change added functions whose entire standard error stream
is redirected to /dev/null using a construct that is valid POSIX.1
but is not widely used:
funcname () {
cd "$1" && run some command "$2"
} 2>/dev/null
Even though this file is "git-completion.bash", zsh completion
support dot-sources it (instead of asking bash to grok it like tcsh
completion does), and zsh does not implement this redirection
correctly.
With zsh, trying to complete an inexistant directory gave this:
git add no-such-dir/__git_ls_files_helper💿2: no such file or directory: no-such-dir/
Also these functions use "cd" to first go somewhere else before
running a command, but the location the caller wants them to go that
is given as an argument to them should not be affected by CDPATH
variable the users may have set for their interactive session.
To fix both of these, wrap the body of the function in a subshell,
unset CDPATH at the beginning of the subshell, and redirect the
standard error stream of the subshell to /dev/null.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We originally thought the transition would need a period where "git add
[-u|-A]" without pathspec would be forbidden, but the warning is big
enough to scare people and teach them not to use it (or, if so, to
understand the consequences).
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-archive relies on get_pathspec to convert its argv into
a list of pathspecs. When get_pathspec is given an empty
argv list, it returns a single pathspec, the empty string,
to indicate that everything matches. When we feed this to
our path_exists function, we typically see that the pathspec
turns up at least one item in the tree, and we are happy.
But when our tree is empty, we erroneously think it is
because the pathspec is too limited, when in fact it is
simply that there is nothing to be found in the tree. This
is a weird corner case, but the correct behavior is almost
certainly to produce an empty archive, not to exit with an
error.
This patch teaches git-archive to create empty archives when
there is no pathspec given (we continue to complain if a
pathspec is given, since it obviously is not matched). It
also confirms that the tar and zip writers produce sane
output in this instance.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We set up the $GIT_UNZIP variable and lazy prereq in
multiple places (and the next patch is about to add another
one). Let's factor it out to avoid repeating ourselves.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git help" translated the "See 'git help <command>' for more
information..." message, but "git" didn't.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If I disable git-shell's interactive mode by removing the
~/git-shell-commands directory, attempts to ssh in to the service
produce a message intended for the administrator:
$ ssh git@myserver
fatal: Interactive git shell is not enabled.
hint: ~/git-shell-commands should exist and have read and execute access.
$
That is helpful for the new admin who is wondering "What? Why isn't
the git-shell I just set up working?", but once the site setup is
complete, it would be better to give the user a friendly hint that she
is on the right track, like GitHub does.
Hi <username>! You've successfully authenticated, but
GitHub does not provide shell access.
An appropriate greeting might even include more complex dynamic
information, like gitolite's list of repositories the user has access
to. Add support for a ~/git-shell-commands/no-interactive-login
command that generates an arbitrary greeting. When the user tries to
log in:
* If the file ~/git-shell-commands/no-interactive-login exists,
run no-interactive-login to let the server say what it likes,
then hang up.
* Otherwise, if ~/git-shell-commands/ is present, start an
interactive read-eval-print loop.
* Otherwise, print the usual configuration hint and hang up.
Reported-by: Ethan Reesor <firelizzard@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Improved-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The original git-shell(1) manpage emphasized that the shell supports
only git transport commands. As the shell gained features, that
emphasis and focus in the manual has been lost. Bring it back by
splitting the manpage into a few short sections and fleshing out each:
- SYNOPSIS, describing how the shell gets used in practice
- DESCRIPTION, which gives an overview of the purpose and guarantees
provided by this restricted shell
- COMMANDS, listing supported commands and restrictions on the
arguments they accept
- INTERACTIVE USE, describing the interactive mode
Also add a "see also" section with related reading.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently the documentation of GIT_PERF_REPEAT_COUNT says the default is
five while "perf-lib.sh" uses a value of three as a default.
Update the documentation so that it is consistent with the code.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even though an earlier attempt (bafc478..41dd00bad) cleaned
up RFC 2047 encoding, pretty.c::add_rfc2047() still decides
where to split the output line by going through the input
one byte at a time, and potentially splits a character in
the middle. A subject line may end up showing like this:
".... fö?? bar". (instead of ".... föö bar".)
if split incorrectly.
RFC 2047, section 5 (3) explicitly forbids such beaviour
Each 'encoded-word' MUST represent an integral number of
characters. A multi-octet character may not be split across
adjacent 'encoded- word's.
that means that e.g. for
Subject: .... föö bar
encoding
Subject: =?UTF-8?q?....=20f=C3=B6=C3=B6?=
=?UTF-8?q?=20bar?=
is correct, and
Subject: =?UTF-8?q?....=20f=C3=B6=C3?= <-- NOTE ö is broken here
=?UTF-8?q?=B6=20bar?=
is not, because "ö" character UTF-8 encoding C3 B6 is split here across
adjacent encoded words.
To fix the problem, make the loop grab one _character_ at a time and
determine its output length to see where to break the output line. Note
that this version only knows about UTF-8, but the logic to grab one
character is abstracted out in mbs_chrlen() function to make it possible
to extend it to other encodings with the help of iconv in the future.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Split the backward-compatibility notes into two sections, the ones
that affect this release, and the other to describe changes meant
for Git 2.0. The latter gives a context to understand why the
changes for this release is necessary.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If an explicit GIT_DIR is given without a working tree, we
implicitly assume that the current working directory should
be used as the working tree. E.g.,:
GIT_DIR=/some/repo.git git status
would compare against the cwd.
Unfortunately, we fool this rule for sub-invocations of git
by setting GIT_DIR internally ourselves. For example:
git init foo
cd foo/.git
git status ;# fails, as we expect
git config alias.st status
git status ;# does not fail, but should
What happens is that we run setup_git_directory when doing
alias lookup (since we need to see the config), set GIT_DIR
as a result, and then leave GIT_WORK_TREE blank (because we
do not have one). Then when we actually run the status
command, we do setup_git_directory again, which sees our
explicit GIT_DIR and uses the cwd as an implicit worktree.
It's tempting to argue that we should be suppressing that
second invocation of setup_git_directory, as it could use
the values we already found in memory. However, the problem
still exists for sub-processes (e.g., if "git status" were
an external command).
You can see another example with the "--bare" option, which
sets GIT_DIR explicitly. For example:
git init foo
cd foo/.git
git status ;# fails
git --bare status ;# does NOT fail
We need some way of telling sub-processes "even though
GIT_DIR is set, do not use cwd as an implicit working tree".
We could do it by putting a special token into
GIT_WORK_TREE, but the obvious choice (an empty string) has
some portability problems.
Instead, we add a new boolean variable, GIT_IMPLICIT_WORK_TREE,
which suppresses the use of cwd as a working tree when
GIT_DIR is set. We trigger the new variable when we know we
are in a bare setting.
The variable is left intentionally undocumented, as this is
an internal detail (for now, anyway). If somebody comes up
with a good alternate use for it, and once we are confident
we have shaken any bugs out of it, we can consider promoting
it further.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The GIT_PREFIX variable is set based on our location within
the working tree. It should therefore be cleared whenever
GIT_WORK_TREE is cleared.
In practice, this doesn't cause any bugs, because none of
the sub-programs we invoke with local_repo_env cleared
actually care about GIT_PREFIX. But this is the right thing
to do, and future proofs us against that assumption changing.
While we're at it, let's define a GIT_PREFIX_ENVIRONMENT
macro; this avoids repetition of the string literal, which
can help catch any spelling mistakes in the code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git checkout -" is a short-hand for "git checkout @{-1}" and the
"@{nth}" notation for a negative number is to find nth previous
checkout in the reflog of the HEAD to determine the name of the
branch the user was on. We would want to find the nth most recent
reflog entry that matches "checkout: moving from X to Y" for this.
Unfortunately, reflog is implemented as an append-only file, and the
API to iterate over its entries, for_each_reflog_ent(), reads the
file in order, giving the entries from the oldest to newer. For the
purpose of finding nth most recent one, this API forces us to record
the last n entries in a rotating buffer and give the result out only
after we read everything. To optimize for a common case of finding
the nth most recent one for a small value of n, we also have a side
API for_each_recent_reflog_ent() that starts reading near the end of
the file, but it still has to read the entries in the "wrong" order.
The implementation of understanding @{-1} uses this interface.
This all becomes unnecessary if we add an API to let us iterate over
reflog entries in the reverse order, from the newest to older.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
