[Bug #19100] Add `init_int32` function to `rb_random_interface_t`

Distinguish initialization by single word from initialization by
array.

1 files changed, 13 insertions, 8 deletions

diff --git a/random.c b/random.c
index 100a54f4e4..759e15335a 100644
--- a/random.c
+++ b/random.c
@@ -371,11 +371,14 @@ rand_init(const rb_random_interface_t *rng, rb_random_t *rnd, VALUE seed)
         INTEGER_PACK_LSWORD_FIRST|INTEGER_PACK_NATIVE_BYTE_ORDER);
     if (sign < 0)
         sign = -sign;
-    if (len > 1) {
+    if (len <= 1) {
+        rng->init_int32(rnd, len ? buf[0] : 0);
+    }
+    else {
         if (sign != 2 && buf[len-1] == 1) /* remove leading-zero-guard */
             len--;
+        rng->init(rnd, buf, len);
     }
-    rng->init(rnd, buf, len);
     explicit_bzero(buf, len * sizeof(*buf));
     ALLOCV_END(buf0);
     return seed;
@@ -892,15 +895,17 @@ rand_mt_load(VALUE obj, VALUE dump)
 }
 
 static void
+rand_mt_init_int32(rb_random_t *rnd, uint32_t data)
+{
+    struct MT *mt = &((rb_random_mt_t *)rnd)->mt;
+    init_genrand(mt, data);
+}
+
+static void
 rand_mt_init(rb_random_t *rnd, const uint32_t *buf, size_t len)
 {
     struct MT *mt = &((rb_random_mt_t *)rnd)->mt;
-    if (len <= 1) {
-        init_genrand(mt, len ? buf[0] : 0);
-    }
-    else {
-        init_by_array(mt, buf, (int)len);
-    }
+    init_by_array(mt, buf, (int)len);
 }
 
 static unsigned int