sprintf.c: Rational f by generic Integer functions

* sprintf.c (rb_str_format): convert Rational to floating point
  format by using gereric Integer functions, not by methods which
  can be overwritten.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54302 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Sun Mar 27 12:13:37 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* sprintf.c (rb_str_format): convert Rational to floating point
+	  format by using gereric Integer functions, not by methods which
+	  can be overwritten.
+
 Sat Mar 26 10:55:12 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* numeric.c (rb_int2str): conversion function to String for

sprintf.c

@@ -1056,22 +1056,19 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
 			sign = -1;
 		    }
 		}
-		else if (rb_num_negative_p(num)) {
+		else if (BIGNUM_NEGATIVE_P(num)) {
 		    sign = -1;
-		    num = rb_funcallv(num, idUMinus, 0, 0);
+		    num = rb_big_uminus(num);
 		}
-		if (den != INT2FIX(1) || prec > 1) {
-		    const ID idDiv = rb_intern("div");
-		    VALUE p10 = rb_int_positive_pow(10, prec);
-		    VALUE den_2 = rb_funcall(den, idDiv, 1, INT2FIX(2));
-		    num = rb_funcallv(num, '*', 1, &p10);
-		    num = rb_funcallv(num, '+', 1, &den_2);
-		    num = rb_funcallv(num, idDiv, 1, &den);
+		if (den != INT2FIX(1)) {
+		    num = rb_int_mul(num, rb_int_positive_pow(10, prec));
+		    num = rb_int_plus(num, rb_int_idiv(den, INT2FIX(2)));
+		    num = rb_int_idiv(num, den);
 		}
 		else if (prec >= 0) {
 		    zero = prec;
 		}
-		val = rb_obj_as_string(num);
+		val = rb_int2str(num, 10);
 		len = RSTRING_LEN(val) + zero;
 		if (prec >= len) ++len; /* integer part 0 */
 		if (sign || (flags&FSPACE)) ++len;