If you have whitespace errors in lines you've introduced, it
can be convenient to be able to jump directly to them for
fixing. You can't quite use "git jump diff" for this,
because though it passes arbitrary options to "git diff", it
expects to see an actual unified diff in the output.
Whereas "git diff --check" actually produces lines that look
like compiler quickfix lines already, meaning we just need
to run it and feed the output directly to the editor.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The hunk-header regex looks for "\+\d+" to find the
post-image line numbers, but it skips the pre-image line
numbers with a simple ".*". That means we may greedily eat
the post-image numbers and match a "\+\d" further on, in the
funcname text.
For example, commit 6b9c38e has this hunk header:
diff --git a/t/t0006-date.sh b/t/t0006-date.sh
[...]
@@ -50,8 +50,8 @@ check_show iso-local "$TIME" '2016-06-15 14:13:20 +0000'
If you run:
git checkout 6b9c38e
git jump diff HEAD^ t/
it will erroneously match "+0000" as the starting line
number and jump there, rather than line 50.
We can fix it by just making the "skip" regex non-greedy,
taking the first "+" we see, which should be the post-image
line information.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our is_hfs_dotgit function relies on the hackily-implemented
next_hfs_char to give us the next character that an HFS+
filename comparison would look at. It's hacky because it
doesn't implement the full case-folding table of HFS+; it
gives us just enough to see if the path matches ".git".
At the end of next_hfs_char, we use tolower() to convert our
32-bit code point to lowercase. Our tolower() implementation
only takes an 8-bit char, though; it throws away the upper
24 bits. This means we can't have any false negatives for
is_hfs_dotgit. We only care about matching 7-bit ASCII
characters in ".git", and we will correctly process 'G' or
'g'.
However, we _can_ have false positives. Because we throw
away the upper bits, code point \u{0147} (for example) will
look like 'G' and get downcased to 'g'. It's not known
whether a sequence of code points whose truncation ends up
as ".git" is meaningful in any language, but it does not
hurt to be more accurate here. We can just pass out the full
32-bit code point, and compare it manually to the upper and
lowercase characters we care about.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the index can block pathnames that can be mistaken
to mean ".git" on NTFS and FAT32, it would be helpful for
fsck to notice such problematic paths. This lets servers
which use receive.fsckObjects block them before the damage
spreads.
Note that the fsck check is always on, even for systems
without core.protectNTFS set. This is technically more
restrictive than we need to be, as a set of users on ext4
could happily use these odd filenames without caring about
NTFS.
However, on balance, it's helpful for all servers to block
these (because the paths can be used for mischief, and
servers which bother to fsck would want to stop the spread
whether they are on NTFS themselves or not), and hardly
anybody will be affected (because the blocked names are
variants of .git or git~1, meaning mischief is almost
certainly what the tree author had in mind).
Ideally these would be controlled by a separate
"fsck.protectNTFS" flag. However, it would be much nicer to
be able to enable/disable _any_ fsck flag individually, and
any scheme we choose should match such a system. Given the
likelihood of anybody using such a path in practice, it is
not unreasonable to wait until such a system materializes.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of disallowing ".git" in the index is that we
would never want to accidentally overwrite files in the
repository directory. But this means we need to respect the
filesystem's idea of when two paths are equal. The prior
commit added a helper to make such a comparison for NTFS
and FAT32; let's use it in verify_path().
We make this check optional for two reasons:
1. It restricts the set of allowable filenames, which is
unnecessary for people who are not on NTFS nor FAT32.
In practice this probably doesn't matter, though, as
the restricted names are rather obscure and almost
certainly would never come up in practice.
2. It has a minor performance penalty for every path we
insert into the index.
This patch ties the check to the core.protectNTFS config
option. Though this is expected to be most useful on Windows,
we allow it to be set everywhere, as NTFS may be mounted on
other platforms. The variable does default to on for Windows,
though.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not allow paths with a ".git" component to be added to
the index, as that would mean repository contents could
overwrite our repository files. However, asking "is this
path the same as .git" is not as simple as strcmp() on some
filesystems.
On NTFS (and FAT32), there exist so-called "short names" for
backwards-compatibility: 8.3 compliant names that refer to the same files
as their long names. As ".git" is not an 8.3 compliant name, a short name
is generated automatically, typically "git~1".
Depending on the Windows version, any combination of trailing spaces and
periods are ignored, too, so that both "git~1." and ".git." still refer
to the Git directory. The reason is that 8.3 stores file names shorter
than 8 characters with trailing spaces. So literally, it does not matter
for the short name whether it is padded with spaces or whether it is
shorter than 8 characters, it is considered to be the exact same.
The period is the separator between file name and file extension, and
again, an empty extension consists just of spaces in 8.3 format. So
technically, we would need only take care of the equivalent of this
regex:
(\.git {0,4}|git~1 {0,3})\. {0,3}
However, there are indications that at least some Windows versions might
be more lenient and accept arbitrary combinations of trailing spaces and
periods and strip them out. So we're playing it real safe here. Besides,
there can be little doubt about the intention behind using file names
matching even the more lenient pattern specified above, therefore we
should be fine with disallowing such patterns.
Extra care is taken to catch names such as '.\\.git\\booh' because the
backslash is marked as a directory separator only on Windows, and we want
to use this new helper function also in fsck on other platforms.
A big thank you goes to Ed Thomson and an unnamed Microsoft engineer for
the detailed analysis performed to come up with the corresponding fixes
for libgit2.
This commit adds a function to detect whether a given file name can refer
to the Git directory by mistake.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the index can block pathnames that case-fold to
".git" on HFS+, it would be helpful for fsck to notice such
problematic paths. This lets servers which use
receive.fsckObjects block them before the damage spreads.
Note that the fsck check is always on, even for systems
without core.protectHFS set. This is technically more
restrictive than we need to be, as a set of users on ext4
could happily use these odd filenames without caring about
HFS+.
However, on balance, it's helpful for all servers to block
these (because the paths can be used for mischief, and
servers which bother to fsck would want to stop the spread
whether they are on HFS+ themselves or not), and hardly
anybody will be affected (because the blocked names are
variants of .git with invisible Unicode code-points mixed
in, meaning mischief is almost certainly what the tree
author had in mind).
Ideally these would be controlled by a separate
"fsck.protectHFS" flag. However, it would be much nicer to
be able to enable/disable _any_ fsck flag individually, and
any scheme we choose should match such a system. Given the
likelihood of anybody using such a path in practice, it is
not unreasonable to wait until such a system materializes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of disallowing ".git" in the index is that we
would never want to accidentally overwrite files in the
repository directory. But this means we need to respect the
filesystem's idea of when two paths are equal. The prior
commit added a helper to make such a comparison for HFS+;
let's use it in verify_path.
We make this check optional for two reasons:
1. It restricts the set of allowable filenames, which is
unnecessary for people who are not on HFS+. In practice
this probably doesn't matter, though, as the restricted
names are rather obscure and almost certainly would
never come up in practice.
2. It has a minor performance penalty for every path we
insert into the index.
This patch ties the check to the core.protectHFS config
option. Though this is expected to be most useful on OS X,
we allow it to be set everywhere, as HFS+ may be mounted on
other platforms. The variable does default to on for OS X,
though.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not allow paths with a ".git" component to be added to
the index, as that would mean repository contents could
overwrite our repository files. However, asking "is this
path the same as .git" is not as simple as strcmp() on some
filesystems.
HFS+'s case-folding does more than just fold uppercase into
lowercase (which we already handle with strcasecmp). It may
also skip past certain "ignored" Unicode code points, so
that (for example) ".gi\u200ct" is mapped ot ".git".
The full list of folds can be found in the tables at:
https://www.opensource.apple.com/source/xnu/xnu-1504.15.3/bsd/hfs/hfscommon/Unicode/UCStringCompareData.h
Implementing a full "is this path the same as that path"
comparison would require us importing the whole set of
tables. However, what we want to do is much simpler: we
only care about checking ".git". We know that 'G' is the
only thing that folds to 'g', and so on, so we really only
need to deal with the set of ignored code points, which is
much smaller.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We complain about ".git" in a tree because it cannot be
loaded into the index or checked out. Since we now also
reject ".GIT" case-insensitively, fsck should notice the
same, so that errors do not propagate.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We check that fsck notices and complains about confusing
paths in trees. However, there are a few shortcomings:
1. We check only for these paths as file entries, not as
intermediate paths (so ".git" and not ".git/foo").
2. We check "." and ".." together, so it is possible that
we notice only one and not the other.
3. We repeat a lot of boilerplate.
Let's use some loops to be more thorough in our testing, and
still end up with shorter code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not allow ".git" to enter into the index as a path
component, because checking out the result to the working
tree may causes confusion for subsequent git commands.
However, on case-insensitive file systems, ".Git" or ".GIT"
is the same. We should catch and prevent those, too.
Note that technically we could allow this for repos on
case-sensitive filesystems. But there's not much point. It's
unlikely that anybody cares, and it creates a repository
that is unexpectedly non-portable to other systems.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We should prevent nonsense paths from entering the index in
the first place, as they can cause confusing results if they
are ever checked out into the working tree. We already do
so, but we never tested it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When unpack_trees tries to write an entry to the index,
add_index_entry may report an error to stderr, but we ignore
its return value. This leads to us returning a successful
exit code for an operation that partially failed. Let's make
sure to propagate this code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The caret (^) is used as a markup symbol in AsciiDoc. Due to the
inability of AsciiDoc to parse a line containing an unmatched caret, it
omitted the line from the output, resulting in the man page missing the
end of a sentence. Escape this caret so that the man page ends up with
the complete text.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify the code and get rid of some magic constants by using
argv_array to build the argument list for cmd_blame. Be lazy and let
the OS release our allocated memory, as before.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We create a directory that cannot be removed, confirm that
it cannot be removed, and then fix it like:
chmod 0 foo &&
test_must_fail git clean -d -f &&
chmod 755 foo
If the middle step fails but leaves the directory (e.g., the
bug is that clean does not notice the failure), this
pollutes the test repo with an unremovable directory. Not
only does this cause further tests to fail, but it means
that "rm -rf" fails on the whole trash directory, and the
user has to intervene manually to even re-run the test script.
We can bump the "chmod 755" recovery to a test_when_finished
block to be sure that it always runs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git merge-base --octopus" used to leave cleaning up suboptimal
result to the caller, but now it does the clean-up itself.
* bm/merge-base-octopus-dedup:
merge-base --octopus: reduce the result from get_octopus_merge_bases()
merge-base: separate "--independent" codepath into its own helper
"git log --left-right A...B" lost the "leftness" of commits
reachable from A when A is a tag as a side effect of a recent
bugfix. This is a regression in 1.8.4.x series.
* jc/revision-range-unpeel:
revision: propagate flag bits from tags to pointees
revision: mark contents of an uninteresting tree uninteresting
"git clone" would fail to clone from a repository that has a ref
directly under "refs/", e.g. "refs/stash", because different
validation paths do different things on such a refname. Loosen the
client side's validation to allow such a ref.
* jk/allow-fetch-onelevel-refname:
fetch-pack: do not filter out one-level refs
A handful of bugs around interpreting $branch@{upstream} notation
and its lookalike, when $branch part has interesting characters,
e.g. "@", and ":", have been fixed.
* jk/interpret-branch-name-fix:
interpret_branch_name: find all possible @-marks
interpret_branch_name: avoid @{upstream} past colon
interpret_branch_name: always respect "namelen" parameter
interpret_branch_name: rename "cp" variable to "at"
interpret_branch_name: factor out upstream handling
A recent update to "git send-email" broke platforms where
/etc/ssl/certs/ directory exists but cannot be used as SSL_ca_path
(e.g. Fedora rawhide).
* rk/send-email-ssl-cert:
send-email: /etc/ssl/certs/ directory may not be usable as ca_path
"git repack --max-pack-size=8g" stopped being parsed correctly when
the command was reimplemented in C.
* sb/repack-in-c:
repack: propagate pack-objects options as strings
repack: make parsed string options const-correct
repack: fix typo in max-pack-size option
The pathspec matching code, while comparing two trees (e.g. "git
diff A B -- path1 path2") was too aggressive and failed to match
some paths when multiple pathspecs were involved.
* as/tree-walk-fix-aggressive-short-cut:
tree_entry_interesting: match against all pathspecs
The documentation to "git pull" hinted there is an "-m" option
because it incorrectly shared the documentation with "git merge".
* jc/maint-pull-docfix:
Documentation: "git pull" does not have the "-m" option
Documentation: exclude irrelevant options from "git pull"
The implementation of 'git stash $cmd "stash@{...}"' did not quote
the stash argument properly and left it split at IFS whitespace.
* ow/stash-with-ifs:
stash: handle specifying stashes with $IFS
There is no reason to have a hardcoded upper limit of the number of
parents for an octopus merge, created via the graft mechanism, but
there was.
* js/lift-parent-count-limit:
Remove the line length limit for graft files
"git add -A" (no other arguments) in a totally empty working tree
used to emit an error.
* nd/add-empty-fix:
add: don't complain when adding empty project root
When we figure out how many file descriptors to allocate for
keeping packfiles open, a system with non-working getrlimit() could
cause us to die(), but because we make this call only to get a
rough estimate of how many is available and we do not even attempt
to use up all file descriptors available ourselves, it is nicer to
fall back to a reasonable low value rather than dying.
* jh/rlimit-nofile-fallback:
get_max_fd_limit(): fall back to OPEN_MAX upon getrlimit/sysconf failure
"git commit -v" appends the patch to the log message before
editing, and then removes the patch when the editor returned
control. However, the patch was not stripped correctly when the
first modified path was a submodule.
* jl/commit-v-strip-marker:
commit -v: strip diffs and submodule shortlogs from the commit message
SSL-related options were not passed correctly to underlying socket
layer in "git send-email".
* tr/send-email-ssl:
send-email: set SSL options through IO::Socket::SSL::set_client_defaults
send-email: --smtp-ssl-cert-path takes an argument
send-email: pass Debug to Net::SMTP::SSL::new
Remote repository URL expressed in scp-style host:path notation are
parsed more carefully (e.g. "foo/bar:baz" is local, "[::1]:/~user" asks
to connect to user's home directory on host at address ::1.
* tb/clone-ssh-with-colon-for-port:
git_connect(): use common return point
connect.c: refactor url parsing
git_connect(): refactor the port handling for ssh
git fetch: support host:/~repo
t5500: add test cases for diag-url
git fetch-pack: add --diag-url
git_connect: factor out discovery of the protocol and its parts
git_connect: remove artificial limit of a remote command
t5601: add tests for ssh
t5601: remove clear_ssh, refactor setup_ssh_wrapper
"git fetch --depth=0" was a no-op, and was silently ignored.
Diagnose it as an error.
* nd/transport-positive-depth-only:
clone,fetch: catch non positive --depth option value
The current basedir compare aborts early in order to avoid futile
recursive searches. However, a match may still be found by another
pathspec. This can cause an error while checking out files from a branch
when using multiple pathspecs:
$ git checkout master -- 'a/*.txt' 'b/*.txt'
error: pathspec 'a/*.txt' did not match any file(s) known to git.
Signed-off-by: Andy Spencer <andy753421@gmail.com>
Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the original shell version of git-repack, any options
destined for pack-objects were left as strings, and passed
as a whole. Since the C rewrite in commit a1bbc6c (repack:
rewrite the shell script in C, 2013-09-15), we now parse
these values to integers internally, then reformat the
integers when passing the option to pack-objects.
This has the advantage that we catch format errors earlier
(i.e., when repack is invoked, rather than when pack-objects
is invoked).
It has three disadvantages, though:
1. Our internal data types may not be the right size. In
the case of "--window-memory" and "--max-pack-size",
these are "unsigned long" in pack-objects, but we can
only represent a regular "int".
2. Our parsing routines might not be the same as those of
pack-objects. For the two options above, pack-objects
understands "100m" to mean "100 megabytes", but repack
does not.
3. We have to keep a sentinel value to know whether it is
worth passing the option along. In the case of
"--window-memory", we currently do not pass it if the
value is "0". But that is a meaningful value to
pack-objects, where it overrides any configured value.
We can fix all of these by simply passing the strings from
the user along to pack-objects verbatim. This does not
actually fix anything for "--depth" or "--window", but these
are converted, too, for consistency.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we use OPT_STRING to parse an option, we get back a
pointer into the argv array, which should be "const char *".
The compiler doesn't notice because it gets passed through a
"void *" in the option struct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we see "--max-pack-size", we accidentally propagated
this to pack-objects as "--max_pack_size", which does not
work at all.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Subversion serf backend in versions 1.8.5 and below has a bug(*) that the
function creating the descriptor of a file change -- add_file() --
doesn't make a copy of its third argument when storing it on the
returned descriptor. As a result, by the time this field is used (in
transactions of file copying or renaming) it may well be released, and
the memory reused.
One of its possible manifestations is the svn assertion triggering on an
invalid path, with a message
svn_fspath__skip_ancestor: Assertion
`svn_fspath__is_canonical(child_fspath)' failed.
This patch works around this bug, by storing the value to be passed as
the third argument to add_file() in a local variable with the same scope
as the file change descriptor, making sure their lifetime is the same.
* [ew: fixed in Subversion r1553376 as noted by Jonathan Nieder]
Cc: Benjamin Pabst <benjamin.pabst85@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Roman Kagan <rkagan@mail.ru>
When sending patches on Fedora rawhide with
git-1.8.5.2-1.fc21.x86_64 and perl-IO-Socket-SSL-1.962-1.fc21.noarch,
with the following
[sendemail]
smtpencryption = tls
smtpserver = smtp.gmail.com
smtpuser = ruben@rubenkerkhof.com
smtpserverport = 587
git-send-email fails with:
STARTTLS failed! SSL connect attempt failed with unknown error
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate
verify failed at /usr/libexec/git-core/git-send-email line 1236.
The current code detects the presence of /etc/ssl/certs directory
(it actually is a symlink to another directory, but that does not
matter) and uses SSL_ca_path to point at it when initializing the
connection with IO::Socket::SSL or Net::SMTP::SSL. However, on the
said platform, it seems that this directory is not designed to be
used as SSL_ca_path. Using a single file inside that directory
(cert.pem, which is a Mozilla CA bundle) with SSL_ca_file does work,
and also not specifying any SSL_ca_file/SSL_ca_path (and letting the
library use its own default) and asking for peer verification does
work.
By removing the code that blindly defaults $smtp_ssl_cert_path to
"/etc/ssl/certs", we can prevent the codepath that treats any
directory specified with that variable as usable for SSL_ca_path
from incorrectly triggering.
This change could introduce a regression for people on a platform
whose certificate directory is /etc/ssl/certs but its IO::Socket:SSL
somehow fails to use it as SSL_ca_path without being told. Using
/etc/ssl/certs directory as SSL_ca_path by default like the current
code does would have been hiding such a broken installation without
its user needing to do anything. These users can still work around
such a platform bug by setting the configuration variable explicitly
to point at /etc/ssl/certs.
This change should not negate what 35035bbf (send-email: be explicit
with SSL certificate verification, 2013-07-18), which was the
original change that introduced the defaulting to /etc/ssl/certs/,
attempted to do, which is to make sure we do not communicate over
insecure connection by default, triggering warning from the library.
Cf. https://bugzilla.redhat.com/show_bug.cgi?id=1043194
Tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Signed-off-by: Ruben Kerkhof <ruben@rubenkerkhof.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With the previous fix 895c5ba3 (revision: do not peel tags used in
range notation, 2013-09-19), handle_revision_arg() that processes
command line arguments for the "git log" family of commands no
longer directly places the object pointed by the tag in the pending
object array when it sees a tag object. We used to place pointee
there after copying the flag bits like UNINTERESTING and
SYMMETRIC_LEFT.
This change meant that any flag that is relevant to later history
traversal must now be propagated to the pointed objects (most often
these are commits) while starting the traversal, which is partly
done by handle_commit() that is called from prepare_revision_walk().
We did propagate UNINTERESTING, but did not do so for others, most
notably SYMMETRIC_LEFT. This caused "git log --left-right v1.0..."
(where "v1.0" is a tag) to start losing the "leftness" from the
commit the tag points at.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-list --objects ^A^{tree} B^{tree}" ought to mean "I want a
list of objects inside B's tree, but please exclude the objects that
appear inside A's tree".
we see the top-level tree marked as uninteresting (i.e. ^A^{tree} in
the above example) and call mark_tree_uninteresting() on it; this
unfortunately prevents us from recursing into the tree and marking
the objects in the tree as uninteresting.
The reason why "git log ^A A" yields an empty set of commits,
i.e. we do not have a similar issue for commits, is because we call
mark_parents_uninteresting() after seeing an uninteresting commit.
The uninteresting-ness of the commit itself does not prevent its
parents from being marked as uninteresting.
Introduce mark_tree_contents_uninteresting() and structure the code
in handle_commit() in such a way that it makes it the responsibility
of the callchain leading to this function to mark commits, trees and
blobs as uninteresting, and also make it the responsibility of the
helpers called from this function to mark objects that are reachable
from them.
Note that this is a very old bug that probably dates back to the day
when "rev-list --objects" was introduced. The line to clear
tree->object.parsed at the end of mark_tree_contents_uninteresting()
can be removed when this fix is merged to the codebase after
6e454b9a (clear parsed flag when we free tree buffers, 2013-06-05).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we parse a string like "foo@{upstream}", we look for
the first "@"-sign, and check to see if it is an upstream
mark. However, since branch names can contain an @, we may
also see "@foo@{upstream}". In this case, we check only the
first @, and ignore the second. As a result, we do not find
the upstream.
We can solve this by iterating through all @-marks in the
string, and seeing if any is a legitimate upstream or
empty-at mark.
Another strategy would be to parse from the right-hand side
of the string. However, that does not work for the
"empty_at" case, which allows "@@{upstream}". We need to
find the left-most one in this case (and we then recurse as
"HEAD@{upstream}").
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>