ash: optimise running of scripts (2)

Commit 4b7b4a960 (ash: optimise running of scripts) avoided creation
of a process when running a script.  There's another case where we
can do the same:  if the script is being run from a FS_SHELLEXEC
shell.

- Check the necessary conditions for this to happen.

- Allocate two extra slots in the argv array for FS_SHELLEXEC.

- Set the index of the script file in the argv array.  Without this
  the test 'pidof this' failed because the command name hadn't been
  correctly set.

Adds 80-96 bytes.

1 files changed, 7 insertions, 0 deletions

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 97dfb3df8..1ff7fe6c8 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -394,6 +394,13 @@ bool re_execed;
 static int interp = 0;
 char bb_comm[COMM_LEN];
 char bb_command_line[128];
+
+# if ENABLE_FEATURE_SH_STANDALONE
+void FAST_FUNC set_interp(int i)
+{
+        interp = i;
+}
+# endif
 #endif