Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in.  When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.

* jk/test-send-sh-x-trace-elsewhere:
  test-lib: set BASH_XTRACEFD automatically

Passing "-x" to a test script enables the shell's "set -x"
tracing, which can help with tracking down the command that
is causing a failure. Unfortunately, it can also _cause_
failures in some tests that redirect the stderr of a shell
function.  Inside the function the shell continues to
respect "set -x", and the trace output is collected along
with whatever stderr is generated normally by the function.

You can see an example of this by running:

  ./t0040-parse-options.sh -x -i

which will fail immediately in the first test, as it
expects:

  test_must_fail some-cmd 2>output.err

to leave output.err empty (but with "-x" it has our trace
output).

Unfortunately there isn't a portable or scalable solution to
this. We could teach test_must_fail to disable "set -x", but
that doesn't help any of the other functions or subshells.

However, we can work around it by pointing the "set -x"
output to our descriptor 4, which always points to the
original stderr of the test script. Unfortunately this only
works for bash, but it's better than nothing (and other
shells will just ignore the BASH_XTRACEFD variable).

The patch itself is a simple one-liner, but note the caveats
in the accompanying comments.

Automatic tests for our "-x" option may be a bit too meta
(and a pain, because they are bash-specific), but I did
confirm that it works correctly both with regular "-x" and
with "--verbose-only=1". This works because the latter flips
"set -x" off and on for particular tests (if it didn't, we
would get tracing for all tests, as going to descriptor 4
effectively circumvents the verbose flag).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

To get the 'value' from '--option=value', test-lib.sh parses said
option running 'expr' with a regexp.  This involves a subshell, an
external process, and a lot of non-alphanumeric characters in the
regexp.

Use a much simpler POSIX-defined shell parameter expansion instead to
do the same.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Test scripts have been updated to remove assumptions that are not
portable between Git for POSIX and Git for Windows, or to skip ones
with expectations that are not satisfiable on Git for Windows.

* js/mingw-tests: (21 commits)
  gitignore: ignore generated test-fake-ssh executable
  mingw: do not bother to test funny file names
  mingw: skip a test in t9130 that cannot pass on Windows
  mingw: handle the missing POSIXPERM prereq in t9124
  mingw: avoid illegal filename in t9118
  mingw: mark t9100's test cases with appropriate prereqs
  t0008: avoid absolute path
  mingw: work around pwd issues in the tests
  mingw: fix t9700's assumption about directory separators
  mingw: skip test in t1508 that fails due to path conversion
  tests: turn off git-daemon tests if FIFOs are not available
  mingw: disable mkfifo-based tests
  mingw: accomodate t0060-path-utils for MSYS2
  mingw: fix t5601-clone.sh
  mingw: let lstat() fail with errno == ENOTDIR when appropriate
  mingw: try to delete target directory before renaming
  mingw: prepare the TMPDIR environment variable for shell scripts
  mingw: factor out Windows specific environment setup
  Git.pm: stop assuming that absolute paths start with a slash
  mingw: do not trust MSYS2's MinGW gettext.sh
  ...

The emulated "yes" command used in our test scripts has been
tweaked not to spend too much time generating unnecessary output
that is not used, to help those who test on Windows where it would
not stop until it fills the pipe buffer due to lack of SIGPIPE.

* js/test-lib-windows-emulated-yes:
  test-lib: limit the output of the yes utility

On Windows, there is no SIGPIPE. A consequence of this is that the
upstream process of a pipe does not notice the death of the downstream
process until the pipe buffer is full and writing more data returns an
error. This behavior is the reason for an annoying delay during the
execution of t7610-mergetool.sh: There are a number of test cases where
'yes' is invoked upstream. Since the utility is basically an endless
loop it runs, on Windows, until the pipe buffer is full. This does take
a few seconds.

The test suite has its own implementation of 'yes'. Modify it to produce
only a limited amount of output that is sufficient for the test suite.
The amount chosen should be sufficiently high for any test case, assuming
that future test cases will not exaggerate their demands of input from
an upstream 'yes' invocation.

[j6t: commit message]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

The description for SANITY prerequisite the test suite uses has
been clarified both in the comment and in the implementation.

* jk/sanity:
  test-lib: clarify and tighten SANITY

MSYS2 (the POSIX emulation layer used by Git for Windows' Bash) actually
has a working mkfifo. The only problem is that it is only emulating
named pipes through the MSYS2 runtime; The Win32 API has no idea about
named pipes, hence the Git executable cannot access those pipes either.

The symptom is that Git fails with a '<name>: No such file or directory'
because MSYS2 emulates named pipes through special-crafted '.lnk' files.

The solution is to tell the test suite explicitly that we cannot use
named pipes when we want to test on Windows.

This lets t4056-diff-order.sh, t9010-svn-fe.sh and t9300-fast-import.sh
pass.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

f400e51c (test-lib.sh: set prerequisite SANITY by testing what we
really need, 2015-01-27) improved the way SANITY prerequisite was
determined, but made the resulting code (incorrectly) imply that
SANITY is all about effects of permission bits of the containing
directory has on the files contained in it by the comment it added,
its log message and the actual tests.

State what SANITY is about more clearly in the comment, and test
that a file whose permission bits says should be unreadble truly
cannot be read.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Running tests with the "-x" option to make them verbose had some
unpleasant interactions with other features of the test suite.

* jk/test-with-x:
  test-lib: disable trace when test is not verbose
  test-lib: turn off "-x" tracing during chain-lint check