ash: revert change to behaviour of -s option

Upstream BusyBox commit f3634584d (ash,hush: show 'c' in $- if run in
"sh -c CMD") changed the behaviour of -s to match that of bash rather
than dash.  This means that the -s and -c options can't be combined.

This combination of options is used by the Windows 'su' applet to
prevent the new console window from shutting down after the command
has run.  It's also useful when the shell is to be run with an
initialisation command (GitHub issue #100).

Revert the change so -s behaves as in dash.

1 files changed, 10 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 690485a83..407a0304c 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -426,7 +426,11 @@ static const char *const optletters_optnames[] = {
         "m"   "monitor",
         "n"   "noexec",
 /* Ditto: bash has no "set -s" */
+#if !ENABLE_PLATFORM_MINGW32
         "s"   "",
+#else
+        "s"   "stdin",
+#endif
         "c"   "",
         "x"   "xtrace",
         "v"   "verbose",
@@ -14990,7 +14994,9 @@ procargs(char **argv)
         }
         if (iflag == 2 /* no explicit -i given */
          && sflag == 1 /* -s given (or implied) */
+#if !ENABLE_PLATFORM_MINGW32
          && !minusc /* bash compat: ash -sc 'echo $-' is not interactive (dash is) */
+#endif
          && isatty(0) && isatty(1) /* we are on tty */
         ) {
                 iflag = 1;
@@ -15254,7 +15260,11 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
                 //  ash -sc 'echo $-'
                 // continue reading input from stdin after running 'echo'.
                 // bash does not do this: it prints "hBcs" and exits.
+#if !ENABLE_PLATFORM_MINGW32
                 evalstring(minusc, EV_EXIT);
+#else
+                evalstring(minusc, sflag ? 0 : EV_EXIT);
+#endif
         }
 
         if (sflag || minusc == NULL) {