run-tests: $TESTDIR can be something else than $PWD
$TESTDIR is expected to be the directory were the test lives, and is often used
to reference helper functions. However, it is now set to $PWD at test invocation
time, so if `run-tests.py` is called from another folder, the test will fail.
The solution is to force $TESTDIR to be the base directory of the test itself,
irrespective of where the runner is called from.
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true