Currently, we have a function to resolve paths, strbuf_realpath. This
function canonicalizes paths like realpath(3), but permits a trailing
component to be absent from the file system. In other words, this is
the behavior of the GNU realpath(1) without any arguments.
In the future, we'll need this same behavior, except that we want to
allow for any number of missing trailing components, which is the
behavior of GNU realpath(1) with the -m option. This is useful because
we'll want to canonicalize a path that may point to a not yet present
path under the .git directory. For example, a user may want to know
where an arbitrary ref would be stored if it existed in the file system.
Let's refactor strbuf_realpath to move most of the code to an internal
function and then pass it two flags to control its behavior. We'll add
a strbuf_realpath_forgiving function that has our new behavior, and
leave strbuf_realpath with the older, stricter behavior.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit continues the work started with previous commit.
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Returning a shared buffer invites very subtle bugs due to reentrancy or
multi-threading, as demonstrated by the previous patch.
There was an unfinished effort to abolish this [1].
Let's finally rid of `real_path()`, using `strbuf_realpath()` instead.
This patch uses a local `strbuf` for most places where `real_path()` was
previously called.
However, two places return the value of `real_path()` to the caller. For
them, a `static` local `strbuf` was added, effectively pushing the
problem one level higher:
read_gitfile_gently()
get_superproject_working_tree()
[1] https://lore.kernel.org/git/1480964316-99305-1-git-send-email-bmwill@google.com/
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The prefix_filename function used to do an early return when
there was no prefix on non-Windows platforms, but always
allocated on Windows so that it could call convert_slashes().
Now that the function always allocates, we can unify the
logic and make convert_slashes() the only conditional part.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The prefix_filename() function returns a pointer to static
storage, which makes it easy to use dangerously. We already
fixed one buggy caller in hash-object recently, and the
calls in apply.c are suspicious (I didn't dig in enough to
confirm that there is a bug, but we call the function once
in apply_all_patches() and then again indirectly from
parse_chunk()).
Let's make it harder to get wrong by allocating the return
value. For simplicity, we'll do this even when the prefix is
empty (and we could just return the original file pointer).
That will cause us to allocate sometimes when we wouldn't
otherwise need to, but this function isn't called in
performance critical code-paths (and it already _might_
allocate on any given call, so a caller that cares about
performance is questionable anyway).
The downside is that the callers need to remember to free()
the result to avoid leaking. Most of them already used
xstrdup() on the result, so we know they are OK. The
remainder have been converted to use free() as appropriate.
I considered retaining a prefix_filename_unsafe() for cases
where we know the static lifetime is OK (and handling the
cleanup is awkward). This is only a handful of cases,
though, and it's not worth the mental energy in worrying
about whether the "unsafe" variant is OK to use in any
situation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function takes the prefix as a ptr/len pair, but in
every caller the length is exactly strlen(ptr). Let's
simplify the interface and just take the string. This saves
callers specifying it (and in some cases handling a NULL
prefix).
In a handful of cases we had the length already without
calling strlen, so this is technically slower. But it's not
likely to matter (after all, if the prefix is non-empty
we'll allocate and copy it into a buffer anyway).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a public function, so we should make its
documentation available near the declaration.
While we're at it, we can give a few details about how it
works.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 4ac9006f83 (real_path: have callers use real_pathdup and
strbuf_realpath, 2016-12-12), we changed the xstrdup(real_path())
pattern to use real_pathdup() directly.
The problem with this change is that real_path() calls
strbuf_realpath() with die_on_error = 1 while real_pathdup() calls
it with die_on_error = 0. Meaning that in cases where real_path()
causes Git to die() with an error message, real_pathdup() is silent
and returns NULL instead.
The callers, however, are ill-prepared for that change, as they expect
the return value to be non-NULL (and otherwise the function died
with an appropriate error message).
Fix this by extending real_pathdup()'s signature to accept the
die_on_error flag and simply pass it through to strbuf_realpath(),
and then adjust all callers after a careful audit whether they would
handle NULLs well.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function that returns a buffer containing the absolute path of its
argument and a semantic patch for its intended use. It avoids an extra
string copy to a static buffer.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Set errno to ELOOP when the maximum number of symlinks is exceeded, as
would be done by other symlink-resolving functions.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The macro 'MAXSYMLINKS' is already defined on macOS and Linux in
<sys/param.h>. If 'MAXSYMLINKS' has already been defined, use the value
defined by the OS otherwise default to a value of 32 which is more
inline with what is allowed by many systems.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When an absolute path is resolved, resolution begins at the first path
component after the root part. The root part is just copied verbatim,
because it must not be inspected for symbolic links. For POSIX paths,
this is just the initial slash, but on Windows, the root part has the
forms c:\ or \\server\share. We do want to canonicalize the back-slashes
in the root part because these parts are compared to the result of
getcwd(), which does return a fully canonicalized path.
Factor out a helper that splits off the root part, and have it
canonicalize the copied part.
This change was prompted because t1504-ceiling-dirs.sh caught a breakage
in GIT_CEILING_DIRECTORIES handling on Windows.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Acked-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create real_pathdup which returns a caller owned string of the resolved
realpath based on the provide path.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the name of real_path_internal to strbuf_realpath. In addition
push the static strbuf up to its callers and instead take as a
parameter a pointer to a strbuf to use for the final result.
This change makes strbuf_realpath reentrant.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current implementation of real_path uses chdir() in order to resolve
symlinks. Unfortunately this isn't thread-safe as chdir() affects a
process as a whole and not just an individual thread. Instead perform
the symlink resolution by hand so that the calls to chdir() can be
removed, making real_path one step closer to being reentrant.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make a few more spots more readable by using the recently introduced,
Windows-specific helper.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move most of the code of absolute_path() into the new function
strbuf_add_absolute_path() and in the process transform it to use
struct strbuf and xgetcwd() instead of a PATH_MAX-sized buffer,
which can be too small on some file systems.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use strbuf instead of fixed-sized buffers in real_path() in order to
avoid the size limitations of the latter.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Store the original working directory in a strbuf instead of in a
fixed-sized buffer, in order to be able to handle longer paths.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some buffers created with PATH_MAX length are not checked when being
written, and can overflow if PATH_MAX is not big enough to hold the
path.
Replace those buffers by strbufs so that their size is automatically
grown if necessary. They are created as static local variables to avoid
reallocating memory on each call. Note that prefix_filename() returns
this static buffer so each callers should copy or use the string
immediately (this is currently true).
Reported-by: Wataru Noguchi <wnoguchi.0727@gmail.com>
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Throughout git, it is assumed that the WIN32 preprocessor symbol is
defined on native Windows setups (mingw and msvc) and not on Cygwin.
On Cygwin, most of the time git can pretend this is just another Unix
machine, and Windows-specific magic is generally counterproductive.
Unfortunately Cygwin *does* define the WIN32 symbol in some headers.
Best to rely on a new git-specific symbol GIT_WINDOWS_NATIVE instead,
defined as follows:
#if defined(WIN32) && !defined(__CYGWIN__)
# define GIT_WINDOWS_NATIVE
#endif
After this change, it should be possible to drop the
CYGWIN_V15_WIN32API setting without any negative effect.
[rj: %s/WINDOWS_NATIVE/GIT_WINDOWS_NATIVE/g ]
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function is like real_path(), except that it returns NULL on error
instead of dying.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
It accepts a new parameter, die_on_error. If die_on_error is false,
it simply cleans up after itself and returns NULL rather than dying.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
The change has two points:
1. Do not strip off a leading slash, because that erroneously turns an
absolute path into a relative path.
2. Do not remove slashes from groups of multiple slashes; instead let
chdir() handle them. It could be, for example, that it wants to
leave leading double-slashes alone.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently parse-options.o pulls quite a big bunch of dependencies.
his complicates it's usage in contrib/ because it pulls external
dependencies and it also increases executables size.
Split off less generic and more internal to git part of
parse-options.c to parse-options-cb.c.
Move prefix_filename function from setup.c to abspath.c. abspath.o
and wrapper.o pull each other, so it's unlikely to increase the
dependencies. It was a dependency of parse-options.o that pulled
many others.
Now parse-options.o pulls just abspath.o, ctype.o, strbuf.o, usage.o,
wrapper.o, libc directly and strlcpy.o indirectly.
Signed-off-by: Dmitry Ivankov <divanorama@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
10c4c88 (Allow add_path() to add non-existent directories to the path,
2008-07-21) introduced get_pwd_cwd() function in order to favor $PWD when
getenv("PWD") and getcwd() refer to the same directory but are different
strings (e.g. the former gives a nicer looking name via a symbolic link to
an uglier looking automounted path). The function tried to determine if
two directories are the same by running stat(2) on both and comparing
ino/dev fields.
Unfortunately, stat() does not fill any ino or dev fields in msysgit. But
there is a telltale: both ino and dev are 0 when they are not filled
correctly, so let's be extra cautious.
This happens to fix a bug in "get-receive-pack working_directory/" when
the GIT_DIR would not be set correctly due to absolute_path(".")
returning the wrong value.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ef/maint-win-verify-path:
verify_dotfile(): do not assume '/' is the path seperator
verify_path(): simplify check at the directory boundary
verify_path: consider dos drive prefix
real_path: do not assume '/' is the path seperator
A Windows path starting with a backslash is absolute
real_path currently assumes it's input had '/' as path seperator.
This assumption does not hold true for the code-path from
prefix_path (on Windows), where real_path can be called before
normalize_path_copy.
Fix real_path so it doesn't make this assumption. Create a helper
function to reverse-search for the last path-seperator in a string.
Signed-off-by: Theo Niessink <theo@taletn.com>
Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.
The function calls have been replaced 1-to-1 in their usage.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some codepaths call make_absolute_path with its own return value as
input. In such a cases, return the path immediately.
This fixes a valgrind-discovered error, whereby we tried to copy a
string onto itself.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Cloning via relative path fails for a project residing immediately under
the root directory of a DOS drive. For instance, for project c:/foo,
issuing "cd c:/" followed by "git clone foo bar" fails with error
"Unable to find remote helper for 'c'". The problem is caused by
make_nonrelative_path() incorrectly returning c://foo rather than
c:/foo for input "foo". The bogus path c://foo is misinterpreted by
transport_get() as a URL with unrecognized protocol "c", hence the
missing remote helper error. Fix make_nonrelative_path() to return
c:/foo rather than c://foo (and /foo rather than //foo on Unix).
Resolves msysgit issue #501 [1]
[PT: squashed in changes requested by Junio [2][3]]
[1] http://code.google.com/p/msysgit/issues/detail?id=501
[2] http://marc.info/?l=git&m=128570102331652&w=2
[3] http://marc.info/?l=git&m=128573246704862&w=2
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When concatenating two paths, if the first one already have '/', do
not put another '/' in between the two paths.
Usually this is not the case as getcwd() won't return '/foo/bar/',
except when you are standing at root, then it will return '/'.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'len' variable was declared at the beginning of the make_absolute_path
function and also in an inner 'if' block which masked the outer declaration.
It is only used in two 'if' blocks, so remove the outer declaration and
make a new declaration inside the other 'if' block that uses 'len'.
Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Lots of die() calls did not actually report the kind of error, which
can leave the user confused as to the real problem. Use die_errno()
where we check a system/library call that sets errno on failure, or
one of the following that wrap such calls:
Function Passes on error from
-------- --------------------
odb_pack_keep open
read_ancestry fopen
read_in_full xread
strbuf_read xread
strbuf_read_file open or strbuf_read_file
strbuf_readlink readlink
write_in_full xwrite
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A simple "grep -e stat --and -e S_ISDIR" revealed there are many
open-coded implementations of this function.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function had used make_absolute_path(); but this function dies if
the directory that contains the entry whose relative path was supplied in
the argument does not exist. This is a problem if the argument is, for
example, "../libexec/git-core", and that "../libexec" does not exist.
Since the resolution of symbolic links is not required for elements in
PATH, we can fall back to using make_nonrelative_path(), which simply
prepends $PWD to the path.
We have to move make_nonrelative_path() alongside make_absolute_path() in
abspath.c so that git-shell can be linked. See 5b8e6f85f.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A lot of modules that have nothing to do with git-shell functionality
were linked in, bloating git-shell more than 8 times.
This patch cuts off redundant dependencies by:
1. providing stubs for three functions that make no sense for git-shell;
2. moving quote_path_fully from environment.c to quote.c to make the
later self sufficient;
3. moving make_absolute_path into a new separate file.
The following numbers have been received with the default optimization
settings on master using GCC 4.1.2:
Before:
text data bss dec hex filename
143915 1348 93168 238431 3a35f git-shell
After:
text data bss dec hex filename
17670 788 8232 26690 6842 git-shell
Signed-off-by: Junio C Hamano <gitster@pobox.com>
