ash,hush: fix $RANDOM in children being repeated

function                                             old     new   delta
next_random                                           46      68     +22
forkshell                                            248     263     +15
expand_vars_to_list                                 2118    2131     +13
run_pipe                                            1775    1782      +7
popstring                                            134     140      +6
builtin_umask                                        123     121      -2
ash_main                                            1356    1336     -20
get_local_var_value                                  125     104     -21
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/3 up/down: 63/-43)             Total: 20 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/shell/random.h b/shell/random.h
index 8667e1c99..e22a2e88b 100644
--- a/shell/random.h
+++ b/shell/random.h
@@ -13,7 +13,13 @@ typedef struct random_t {
         uint32_t LCG;        /* LCG (fast but weak) */
 } random_t;
 
+#define UNINITED_RANDOM_T(rnd) \
+        ((rnd)->galois_LFSR == 0)
+
 #define INIT_RANDOM_T(rnd, nonzero, v) \
         ((rnd)->galois_LFSR = (nonzero), (rnd)->LCG = (v))
 
+#define CLEAR_RANDOM_T(rnd) \
+        ((rnd)->galois_LFSR = 0)
+
 uint32_t next_random(random_t *rnd) FAST_FUNC;