The "git" command prepends the exec-path to the PATH environment
variable for processes it spawns.  That is how ". git-sh-setup" in
our scripted Porcelains can find the dot-sourced file in the
exec-path location that is not usually on user's PATH.

When t2300 runs, because it is not spawned by the "git" command, the
scriptlet being tested did not run with a realistic setting of PATH
environment.  It lacked the exec-path on the PATH, and failed to
find the dot-sourced file.  A recent update to t2300 attempted to
fix this, with "PATH=$(git --exec-path):$PATH", which has been the
recommended way around v1.6.0 days (a script whose original was
written before that release that survives to this day is likely to
have such a line).

However, the "git --exec-path" command outputs C:\path\to\exec\dir
(not /c/path/to/exec/dir) on Windows; the recent update failed to
consider the problem that comes from it.

Even though Git itself, when doing the equivalent internally, does
so in a platform native way (i.e. on Windows, C:\path\to\exec\dir is
prepended to the existing value of %PATH% using ';' as a component
separator), the result is further massaged by bash and gets turned
into $PATH that uses /c/path/to/exec/dir with ':' separating the
components, which is the form understood by bash, so scripted
Porcelains find commands from PATH correctly.

An end user script written in shell, however, cannot prepend
"C:\path\to\exec\dir:" to the existing value of $PATH and expect
bash to magically turn it into the form it understands.  In other
words, "PATH=$(git --exec-path):$PATH" does not work as an emulation
of what "Git" internally does to the PATH on Windows.

To correctly emulate how exec-path is prepended to the PATH
environment internally on Windows, we'd need to convert
C:\git-sdk-64\usr\src\git to at least /c\git-sdk-64\usr\src\git
ourselves before prepending it to PATH.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we run scripted Porcelains, "git" potty has set up the $PATH by
prepending $GIT_EXEC_PATH, the path given by "git --exec-path=$there
$cmd", etc. already.  Because of this, scripted Porcelains can
dot-source shell script library like git-sh-setup with simple dot
without specifying any path.

t2300 however dot-sources git-sh-setup without adjusting $PATH like
the real "git" potty does.  This has not been a problem so far, but
once git-sh-setup wants to rely on the $PATH adjustment, just like
any scripted Porcelains already do, it would become one.  It cannot
for example dot-source another shell library without specifying the
full path to it by prefixing $(git --exec-path).
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is needed to allow the test suite to run against a standard
install bin directory instead of GIT_EXEC_PATH.
Signed-off-by: NMatthew Ogilvie <mmogilvi_git@miniinfo.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Many tests depend on that symbolic links work.  This introduces a check
that sets the prerequisite tag SYMLINKS if the file system supports
symbolic links.  Since so many tests have to check for this prerequisite,
we do the check in test-lib.sh, so that we don't need to repeat the test
in many scripts.

To check for 'ln -s' failures, you can use a FAT partition on Linux:

$ mkdosfs -C git-on-fat 1000000
$ sudo mount -o loop,uid=j6t,gid=users,shortname=winnt git-on-fat /mnt

Clone git to /mnt and

$ GIT_SKIP_TESTS='t0001.1[34] t0010 t1301 t403[34] t4129.[47] t5701.7
          t7701.3 t9100 t9101.26 t9119 t9124.[67] t9200.10 t9600.6' \
        make test

(These additionally skipped tests depend on POSIX permissions that FAT on
Linux does not provide.)
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>

In cd_to_toplevel, instead of 'cd $(unset PWD; /bin/pwd)/$path'
use 'cd -P $path'.  The "-P" option yields a desirable similarity to
C chdir.

While the "-P" option may be slightly less commonly supported than
/bin/pwd, it is more concise, better tested, and less error prone.
I've already added the 'unset PWD' to fix the /bin/pwd solution on
BSD; there may be more edge cases out there.

This still passes all the same test cases in t5521-pull-symlink.sh and
t2300-cd-to-toplevel.sh, even before updating them to use 'pwd -P'.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

On Mac OS X and possibly BSDs, /bin/pwd reads PWD from the environment if
available and shows the logical path by default rather than the physical
one.

Unset PWD before running /bin/pwd in both cd_to_toplevel and its test.

Still use the external /bin/pwd because in my Bash on Linux, the builtin
pwd prints the same result whether or not PWD is set.
Signed-off-by: NMarcel M. Cary <marcel@oak.homeunix.org>
Tested-by: Wincent Colaiuta <win@wincent.com> (on Mac OS X 10.5.5)
Tested-by: Marcel Koeppen <git-dev@marzelpan.de> (on Mac OS X 10.5.6)
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

I want directories of my working tree to be linked to from various
paths on my filesystem where third-party components expect them, both
in development and production environments.  A build system's install
step could solve this, but I develop scripts and web pages that don't
need to be built.  Git's submodule system could solve this, but we
tend to develop, branch, and test those directories all in unison, so
one big repository feels more natural.  We prefer to edit and commit
on the symlinked paths, not the canonical ones, and in that setting,
"git pull" fails to find the top-level directory of the repository
while other commands work fine.

"git pull" fails because POSIX shells have a notion of current working
directory that is different from getcwd().  The shell stores this path
in PWD.  As a result, "cd ../" can be interpreted differently in a
shell script than chdir("../") in a C program.  The shell interprets
"../" by essentially stripping the last textual path component from
PWD, whereas C chdir() follows the ".." link in the current directory
on the filesystem.  When PWD is a symlink, these are different
destinations.  As a result, Git's C commands find the correct
top-level working tree, and shell scripts do not.

Changes:

* When interpreting a relative upward (../) path in cd_to_toplevel,
  prepend the cwd without symlinks, given by /bin/pwd
* Add tests for cd_to_toplevel and "git pull" in a symlinked
  directory that failed before this fix, plus contrasting scenarios
  that already worked
Signed-off-by: NMarcel M. Cary <marcel@oak.homeunix.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>