Attached are a couple of patches to improve the TAP driver.  I don't know if `--merge-prefix' is the best name for the new option; suggestions for alternatives would be appreciated.

Thanks,
Richard


[PATCH 1/2] tap: new `--merge-prefix' option to prefix stderr before merging

* lib/tap-driver.sh: Add a new `--merge-prefix' option to direct the TAP
driver to prefix each line of the test script's standard error with the given
string before merging it with the test script's standard output.  This is
useful when standard error lines might be confused with test results.
* doc/automake.texi: Document the new `--merge-prefix' option.
* t/tap-merge-prefix.sh: New test.
* t/list-of-tests.mk (handwritten_TESTS): Add it.

[PATCH 2/2] tap: close fd 3 when invoking the test script

* lib/tap-driver.sh: Close file descriptor 3 when invoking the test script to
avoid potential conflicts with the test script.