make a few struct bb_applet members conditional

rename sllep_and_die -> xfunc_die
make fflush_stdout_and_exit NOFORK-safe
fix some buglets found by randomconfig

1 files changed, 16 insertions, 5 deletions

diff --git a/libbb/error_msg_and_die.c b/libbb/error_msg_and_die.c
index 39178a3ce..4a9049364 100644
--- a/libbb/error_msg_and_die.c
+++ b/libbb/error_msg_and_die.c
@@ -10,14 +10,25 @@
 #include "libbb.h"
 
 int die_sleep;
+#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
 jmp_buf die_jmp;
+#endif
 
-void sleep_and_die(void)
+void xfunc_die(void)
 {
 	if (die_sleep) {
-		/* Special case: don't die, but jump */
-		if (die_sleep < 0)
-			longjmp(die_jmp, xfunc_error_retval);
+		if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && die_sleep < 0) {
+			/* Special case. We arrive here if NOFORK applet
+			 * calls xfunc, which then decides to die.
+			 * We don't die, but jump instead back to caller.
+			 * NOFORK applets still cannot carelessly call xfuncs:
+			 * p = xmalloc(10);
+			 * q = xmalloc(10); // BUG! if this dies, we leak p!
+			 */
+			/* -111 means "zero" (longjmp can't pass 0)
+			 * spawn_and_wait() catches -111. */
+			longjmp(die_jmp, xfunc_error_retval ? xfunc_error_retval : -111);
+		}
 		sleep(die_sleep);
 	}
 	exit(xfunc_error_retval);
@@ -30,5 +41,5 @@ void bb_error_msg_and_die(const char *s, ...)
 	va_start(p, s);
 	bb_verror_msg(s, p, NULL);
 	va_end(p);
-	sleep_and_die();
+	xfunc_die();
 }