runner: pass full expanded command as one sh -c arg (8u0)

runner_run built "/bin/sh -c " + cmd and ran g_shell_parse_argv on it,
which split the command into argv words — sh -c then received only the
first word as its script and treated the rest as $0/$1..., silently
truncating multi-word commands, pipelines, and redirections. The
existing 'true %f' test passed only because true ignores missing args.

Build argv directly as {"/bin/sh", "-c", c_cmd, NULL} so sh -c gets
the whole expanded command as one script string. %f/%d stay single-
quoted via g_shell_quote, so hostile filenames cannot break out of the
quotes and inject commands. Also removed dead code in _shell_quote.

New observable tests (write to a temp file, read it back):
- multi_word: printf 'hello world' (would fail on old code)
- pipeline: echo | cat
- redirection: echo > file
- spaces_in_args: printf 'a b c'
- hostile_filename: ';touch sentinel;' name must NOT create the sentinel

0 files changed, 0 insertions, 0 deletions