[PATCH v2] t/perf: do not run tests in user's $SHELL

The environment variable $SHELL is usually set to the user's interactive shell. Our build and test scripts never use $SHELL because there are no guarantees about its input language. Instead, we use /bin/sh which should be a POSIX shell.

For systems with a broken /bin/sh, we allow to override that path via SHELL_PATH. To run tests in yet another shell we allow to override SHELL_PATH with TEST_SHELL_PATH.

Perf tests run in $SHELL via a wrapper defined in t/perf/perf-lib.sh, so they break with e.g. SHELL=python. Use TEST_SHELL_PATH like in other tests. TEST_SHELL_PATH is always defined because t/perf/perf-lib.sh includes t/test-lib.sh, which includes GIT-BUILD-OPTIONS.

Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Johannes Altmanninger <aclopte@gmail.com>
---
 t/perf/perf-lib.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

I extended the commit message because in hindsight it was overly terse (judging from both re-reading it and from review comments).

We could add more Acked-bys but one seems enough here.

range-diff to the first version:

    @@ Commit message
         t/perf: do not run tests in user's $SHELL
     
         The environment variable $SHELL is usually set to the user's
    -    interactive shell. We never use that shell for build and test scripts
    -    because it might not be a POSIX shell.
    +    interactive shell. Our build and test scripts never use $SHELL because
    +    there are no guarantees about its input language.  Instead, we use
    +    /bin/sh which should be a POSIX shell.
     
    -    Perf tests are run inside $SHELL via a wrapper defined in
    -    t/perf/perf-lib.sh. Use $TEST_SHELL_PATH like elsewhere.
    +    For systems with a broken /bin/sh, we allow to override that path via
    +    SHELL_PATH.  To run tests in yet another shell we allow to override
    +    SHELL_PATH with TEST_SHELL_PATH.
    +
    +    Perf tests run in $SHELL via a wrapper defined in t/perf/perf-lib.sh,
    +    so they break with e.g. SHELL=python.  Use TEST_SHELL_PATH like
    +    in other tests.  TEST_SHELL_PATH is always defined because
    +    t/perf/perf-lib.sh includes t/test-lib.sh, which includes
    +    GIT-BUILD-OPTIONS.
    +
    +    Acked-by: Jeff King <peff@peff.net>