* random.c (random_raw_seed): Avoid calling fill_random_bytes()

if the requested size is 0. AIX returns -1 for 0-byte read from
/dev/urandom, while other UNIX returns 0. With this change,
Random.raw_seed(0) consistently retuns "" in any UNIX.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49844 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Thu Mar  5 08:31:02 2015  Rei Odaira  <Rei.Odaira@gmail.com>
+
+	* random.c (random_raw_seed): Avoid calling fill_random_bytes()
+	  if the requested size is 0. AIX returns -1 for 0-byte read from
+	  /dev/urandom, while other UNIX returns 0. With this change,
+	  Random.raw_seed(0) consistently retuns "" in any UNIX.
+
 Wed Mar  4 12:43:32 2015  Kazuki Tanaka  <gogotanaka@ruby-lang.org>
 
 	* test/ruby/test_math.rb (assert_float_and_int): Refactor test cases

random.c

@@ -580,6 +580,7 @@ random_raw_seed(VALUE self, VALUE size)
 {
     long n = NUM2ULONG(size);
     VALUE buf = rb_str_new(0, n);
+    if (n == 0) return buf;
     if (fill_random_bytes(RSTRING_PTR(buf), n)) return Qnil;
     return buf;
 }