This was supposed to be working already but didn't work when we
specified several tests with --only. This patch not only fixes this
but also makes it possible to specify a subset of tests to run with the
TEST environment variable, like the make build system. Here are some
hadrian/build.sh test --only=plugins01 hadrian/build.sh test --only="plugins01 plugins02" TEST="plugins01 plugins02" hadrian/build.sh test TEST=plugins03 hadrian/build.sh test --only="plugins01 plugins02"
When both the TEST environment variable and the --only flag are used,
we simply concatenate the list of tests from both sources and ask the
testsuite driver to run them all.
This patch addresses Trac #16026.