Running `export` when there is no environment variable to export will
cause the environment on the remote host to be printed. We don't want
that, so don't run any `export` command on the host when there's no env.
This was originally committed as f8452ddfcc and reverted in 7cb1aa9d93.
The issue was that shell builtins were being escaped too, and apparently
Bash won't execute a builtin when it is quoted e.g. '!'. Instead, it
thinks it's a command and it can't find it.
Re-committing the change with that issue fixed.
On Windows, we must make sure to close the temporary tar file before we
try to scp it.
This is an alternative approach to https://reviews.llvm.org/D77500.
The benefit of doing this is that we can now handle directories that
contain symlinks and other arbitrary things, such as the static_test_env
required by filesystem tests.
As a fly-by fix, we also accumulate several commands to perform over SSH
and execute them at once instead of SSHing several times. This should be
faster on average.
If a ShTest has for example another command in front of the test
executable it wants to execute, ssh.py needs to properly translate
the path of that test executable to the executable on the remote host.
For example, running '%{exec} ! %t.exe', we can't assume that the
test-executable is the first argument after '%{exec}'.
Louis Dionne