File descriptors 3 and 4 are special in our test suite, as
they link back to the test script's original stdout and
stderr. Normally this isn't something tests need to worry
about: they are free to clobber these descriptors for
sub-commands without affecting the overall script.
But there's one very special thing about descriptor 4: since
d88785e424 (test-lib: set BASH_XTRACEFD automatically,
2016-05-11), we ask bash to output "set -x" output to it by
number. This goes to _any_ descriptor 4, even if it no
longer points to the place it did when we set BASH_XTRACEFD.
But in t5615, we run a shell loop with descriptor 4
redirected. As a result, t5615 works with non-bash shells
even with "-x". And it works with bash without "-x". But the
combination of "bash t5615-alternate-env.sh -x" gets a test
failure (because our "set -x" output pollutes one of the
files).
We can fix this by using any descriptor _except_ the magical
4. So let's switch arbitrarily to using 5/6 in this loop,
not 3/4.
Another alternative is to use a different descriptor for
BASH_XTRACEFD. But picking an unused one turns out to be
hard. Most shells limit us to 9 numbered descriptors. Bash
can handle more, but:
- while the BASH_XTRACEFD is specific to bash, GIT_TRACE=4
has a similar problem, and would affect all shells
- constructs like "999>/dev/null" are synticatically
invalid to non-bash shells. So we have to actually bury
it inside an eval, which creates more complications.
Of the numbers 1-9, you might think that "9" would be less
used than "4". But it's not; many of our scripts use
descriptors 8 and 9 (probably under the assumption that they
are high and therefore unused). The least-used descriptor is
currently "7". We could switch to that, but we're just
trading one magic number for another.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This came as part of jk/quote-env-path-list-component and was merged
to 2.11.1 and later.
Noticed-by: Jan Palus <jan.palus@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A recent update to receive-pack to make it easier to drop garbage
objects made it clear that GIT_ALTERNATE_OBJECT_DIRECTORIES cannot
have a pathname with a colon in it (no surprise!), and this in turn
made it impossible to push into a repository at such a path. This
has been fixed by introducing a quoting mechanism used when
appending such a path to the colon-separated list.
* jk/quote-env-path-list-component:
t5615-alternate-env: double-quotes in file names do not work on Windows
t5547-push-quarantine: run the path separator test on Windows, too
tmp-objdir: quote paths we add to alternates
alternates: accept double-quoted paths
We read lists of alternates from objects/info/alternates
files (delimited by newline), as well as from the
GIT_ALTERNATE_OBJECT_DIRECTORIES environment variable
(delimited by colon or semi-colon, depending on the
platform).
There's no mechanism for quoting the delimiters, so it's
impossible to specify an alternate path that contains a
colon in the environment, or one that contains a newline in
a file. We've lived with that restriction for ages because
both alternates and filenames with colons are relatively
rare, and it's only a problem when the two meet. But since
722ff7f87 (receive-pack: quarantine objects until
pre-receive accepts, 2016-10-03), which builds on the
alternates system, every push causes the receiver to set
GIT_ALTERNATE_OBJECT_DIRECTORIES internally.
It would be convenient to have some way to quote the
delimiter so that we can represent arbitrary paths.
The simplest thing would be an escape character before a
quoted delimiter (e.g., "\:" as a literal colon). But that
creates a backwards compatibility problem: any path which
uses that escape character is now broken, and we've just
shifted the problem. We could choose an unlikely escape
character (e.g., something from the non-printable ASCII
range), but that's awkward to use.
Instead, let's treat names as unquoted unless they begin
with a double-quote, in which case they are interpreted via
our usual C-stylke quoting rules. This also breaks
backwards-compatibility, but in a smaller way: it only
matters if your file has a double-quote as the very _first_
character in the path (whereas an escape character is a
problem anywhere in the path). It's also consistent with
many other parts of git, which accept either a bare pathname
or a double-quoted one, and the sender can choose to quote
or not as required.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have to use $PWD instead of $(pwd) because on Windows the latter
would add a C: style path to bash's Unix-style $PATH variable, which
becomes confused by the colon after the drive letter. ($PWD is a
Unix-style path.)
In the case of GIT_ALTERNATE_OBJECT_DIRECTORIES, bash on Windows
assembles a Unix-style path list with the colon as separators. It
converts the value to a Windows-style path list with the semicolon as
path separator when it forwards the variable to git.exe. The same
confusion happens when bash's original value is contaminated with
Windows style paths.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 670c359da (link_alt_odb_entry: handle normalize_path
errors, 2016-10-03) regressed the handling of relative paths
in the GIT_ALTERNATE_OBJECT_DIRECTORIES variable. It's not
entirely clear this was ever meant to work, but it _has_
worked for several years, so this commit restores the
original behavior.
When we get a path in GIT_ALTERNATE_OBJECT_DIRECTORIES, we
add it the path to the list of alternate object directories
as if it were found in objects/info/alternates, but with one
difference: we do not provide the link_alt_odb_entry()
function with a base for relative paths. That function
doesn't turn it into an absolute path, and we end up feeding
the relative path to the strbuf_normalize_path() function.
Most relative paths break out of the top-level directory
(e.g., "../foo.git/objects"), and thus normalizing fails.
Prior to 670c359da, we simply ignored the error, and due to
the way normalize_path_copy() was implemented it happened to
return the original path in this case. We then accessed the
alternate objects using this relative path.
By storing the relative path in the alt_odb list, the path
is relative to wherever we happen to be at the time we do an
object lookup. That means we look from $GIT_DIR in a bare
repository, and from the top of the worktree in a non-bare
repository.
If this were being designed from scratch, it would make
sense to pick a stable location (probably $GIT_DIR, or even
the object directory) and use that as the relative base,
turning the result into an absolute path. However, given
the history, at this point the minimal fix is to match the
pre-670c359da behavior.
We can do this simply by ignoring the error when we have no
relative base and using the original value (which we now
reliably have, thanks to strbuf_normalize_path()).
That still leaves us with a relative path that foils our
duplicate detection, and may act strangely if we ever
chdir() later in the process. We could solve that by storing
an absolute path based on getcwd(). That may be a good
future direction; for now we'll do just the minimum to fix
the regression.
The new t5615 script demonstrates the fix in its final three
tests. Since we didn't have any tests of the alternates
environment variable at all, it also adds some tests of
absolute paths.
Reported-by: Bryan Turner <bturner@atlassian.com>
Signed-off-by: Jeff King <peff@peff.net>
