* numeric.c (fix_pow): returns infinity for 0**-1. [ruby-dev:32084]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13785 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Fri Oct 26 17:01:34 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* numeric.c (fix_pow): returns infinity for 0**-1.  [ruby-dev:32084]
+
 Fri Oct 26 15:00:52 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* misc/ruby-style.el (ruby-style-{case,label}-indent): adjust for

numeric.c

@@ -2326,6 +2326,7 @@ int_pow(long x, unsigned long y)
 static VALUE
 fix_pow(VALUE x, VALUE y)
 {
+    static const double zero = 0.0;
     long a = FIX2LONG(x);
 
     if (FIXNUM_P(y)) {
@@ -2333,7 +2334,10 @@ fix_pow(VALUE x, VALUE y)
 
 	if (b == 0) return INT2FIX(1);
 	if (b == 1) return x;
-	if (a == 0) return INT2FIX(0);
+	if (a == 0) {
+	    if (b > 0) return INT2FIX(0);
+	    return rb_float_new(1.0 / zero);
+	}
 	if (a == 1) return INT2FIX(1);
 	if (a == -1) {
 	    if (b % 2 == 0)
@@ -2357,7 +2361,9 @@ fix_pow(VALUE x, VALUE y)
 	x = rb_int2big(FIX2LONG(x));
 	return rb_big_pow(x, y);
       case T_FLOAT:
-	if (a == 0) return rb_float_new(0.0);
+	if (a == 0) {
+	    return rb_float_new(RFLOAT(y)->value < 0 ? (1.0 / zero) : 0.0);
+	}
 	if (a == 1) return rb_float_new(1.0);
 	return rb_float_new(pow((double)a, RFLOAT(y)->value));
       default: