From d22ce4a522141c2f6e847846944ddc1ec3a949f2 Mon Sep 17 00:00:00 2001
From: marcandre <marcandre@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 5 Feb 2013 05:39:49 +0000
Subject: * numeric.c (fix_pow): Handle special cases when base is 0, -1 or +1 
  [Bug #5713] [Bug #5715]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39064 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog                |  7 +++++++
 numeric.c                | 22 ++++++++++------------
 test/ruby/test_fixnum.rb | 19 +++++++++++++++++++
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index d22edf6211..80ab00e595 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Feb  5 14:36:04 2013  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
+
+	* numeric.c (fix_pow): Handle special cases when base is 0, -1 or +1
+	  [Bug #5713] [Bug #5715]
+
+	* rational.c (nurat_expt): ditto
+
 Tue Feb  5 13:27:53 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/io/console/console.c (rawmode_opt): use default values by `stty
diff --git a/numeric.c b/numeric.c
index 4ae5948cf0..cacccb9df6 100644
--- a/numeric.c
+++ b/numeric.c
@@ -2951,6 +2951,13 @@ fix_pow(VALUE x, VALUE y)
     if (FIXNUM_P(y)) {
 	long b = FIX2LONG(y);
 
+	if (a == 1) return INT2FIX(1);
+	if (a == -1) {
+	    if (b % 2 == 0)
+		return INT2FIX(1);
+	    else
+		return INT2FIX(-1);
+	}
 	if (b < 0)
 	    return rb_funcall(rb_rational_raw1(x), rb_intern("**"), 1, y);
 
@@ -2960,27 +2967,18 @@ fix_pow(VALUE x, VALUE y)
 	    if (b > 0) return INT2FIX(0);
 	    return DBL2NUM(INFINITY);
 	}
-	if (a == 1) return INT2FIX(1);
-	if (a == -1) {
-	    if (b % 2 == 0)
-		return INT2FIX(1);
-	    else
-		return INT2FIX(-1);
-	}
 	return int_pow(a, b);
     }
     switch (TYPE(y)) {
       case T_BIGNUM:
-
-	if (negative_int_p(y))
-	    return rb_funcall(rb_rational_raw1(x), rb_intern("**"), 1, y);
-
-	if (a == 0) return INT2FIX(0);
 	if (a == 1) return INT2FIX(1);
 	if (a == -1) {
 	    if (int_even_p(y)) return INT2FIX(1);
 	    else return INT2FIX(-1);
 	}
+	if (negative_int_p(y))
+	    return rb_funcall(rb_rational_raw1(x), rb_intern("**"), 1, y);
+	if (a == 0) return INT2FIX(0);
 	x = rb_int2big(FIX2LONG(x));
 	return rb_big_pow(x, y);
       case T_FLOAT:
diff --git a/test/ruby/test_fixnum.rb b/test/ruby/test_fixnum.rb
index 4567da0a60..85c8bdfa7b 100644
--- a/test/ruby/test_fixnum.rb
+++ b/test/ruby/test_fixnum.rb
@@ -279,4 +279,23 @@ class TestFixnum < Test::Unit::TestCase
   def test_frozen
     assert_equal(true, 1.frozen?)
   end
+
+  def assert_eql(a, b, mess)
+    assert a.eql?(b), "expected #{a} & #{b} to be eql? #{mess}"
+  end
+
+  def test_power_of_1_and_minus_1
+    bug5715 = '[ruby-core:41498]'
+    big = 1 << 66
+    assert_eql  1, 1 ** -big        , bug5715
+    assert_eql  1, (-1) ** -big     , bug5715
+    assert_eql -1, (-1) ** -(big+1) , bug5715
+  end
+
+  def test_power_of_0
+    bug5713 = '[ruby-core:41494]'
+    big = 1 << 66
+    assert_raise(ZeroDivisionError, bug5713) { 0 ** -big }
+    assert_raise(ZeroDivisionError, bug5713) { 0 ** Rational(-2,3) }
+  end
 end
-- 
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