From 623db252508b759dbe5e2b5a72914fd845e1510e Mon Sep 17 00:00:00 2001
From: James Roseborough <james.roseborough@luaj.org>
Date: Fri, 22 May 2009 16:41:28 +0000
Subject: [PATCH] Fix hash code for doubles, add unit test to compare with
 integer hash codes.

---
 bin/LuaJit0.class                             | Bin 0 -> 1140 bytes
 src/core/org/luaj/vm/LDouble.java             |   2 +-
 .../java/org/luaj/compiler/SimpleTests.java   |  22 ++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 bin/LuaJit0.class

diff --git a/bin/LuaJit0.class b/bin/LuaJit0.class
new file mode 100644
index 0000000000000000000000000000000000000000..dd42a9934813211366155f238f9c38067a4306d8
GIT binary patch
literal 1140
zcmZ`(YflqV5IwiM+qLa2lt)1XM4)J2P##*9Vo@<BHI-;;>IW0;LRV5)x}@Eb_^XVD
zN8$&6fIrH3Zi|H_nx=E-&g0CPJJbI9{o^NqRXh)405eM52_cHv5auwiw1g51A>75i
z5RynKkq%R2l$KT6qKPFFIf1~zvcPEBZSCcpj<ugVKFpP?mea8d%C{mA+-Ni#UQs|x
zrm6z^mRq+42Fs16z1=z7v0Lw~9Y<N(wpZ?0Z(6SBdS8xcnN0d&`>uilGWQ$amgP7m
zNFe-*7sqXPTFjHBX47tMIaa%Ew*@NKU^-UCvpl=t2k)}DVk3Hvp#7SO%L?7{;fmX7
z?b<IJin}Cn`j?mXtz%1K7$Xv67?)VVs);p;`*<KRh?v9>VkYtu5An#vV~KSXBsP?I
zf}+Hx3Ve!Z?C%0oV50xH*GUN^{_DF!SU?;J-1Ilx?~H>Q>!Yag^*zix5Qu;9C;pvo
z%$Ky?a5&=aQdwZwA5RZUjQXN4X21;3B{fmvV(eILK4p|!RQ<GPdtPrXir1#stM0GR
zv!(uJ6foMJwaYg2T`mi+$x<m*#Vj{`fWLwOKb%Wf<7jwlU<VkX9OZ4Ar{HO%&mq21
z;d@X9dq(JL%+yur3#Mv3r_z~o1kxwaPN2U|XSLN+re}2?!ApcO7>o^3Mo2{xA&N;-
z;+!ybf%uhpQAX{3hq<mRVPsBlgWphHujeC5(QENYEiW@!7BtQfUe~DvyMd9o)M^uY
zg<(|n+JsTb#HCR?C4{b>LB?e~QfID;qw$hlzFRg%azhBS!EutBBdtZuV2xT4^C%&K
gw^+b?{u_Km3ZIeYTTYX10Jqr+n91E`OSdrf2cHJ?UjP6A

literal 0
HcmV?d00001

diff --git a/src/core/org/luaj/vm/LDouble.java b/src/core/org/luaj/vm/LDouble.java
index af82c564..3e00c5e2 100644
--- a/src/core/org/luaj/vm/LDouble.java
+++ b/src/core/org/luaj/vm/LDouble.java
@@ -47,7 +47,7 @@ public class LDouble extends LNumber {
 			int iz = (int) m_value;
 			if ( iz == m_value ) return iz;
 			long bits = Double.doubleToLongBits( m_value );
-			return ( (int) bits >> 32 ) + ( (int) bits );
+			return ((int) (bits >> 32)) + ((int)bits);
 		}
 	}
 	
diff --git a/src/test/java/org/luaj/compiler/SimpleTests.java b/src/test/java/org/luaj/compiler/SimpleTests.java
index 18a0df6e..a20cb9d3 100644
--- a/src/test/java/org/luaj/compiler/SimpleTests.java
+++ b/src/test/java/org/luaj/compiler/SimpleTests.java
@@ -8,6 +8,8 @@ import junit.framework.TestCase;
 import org.luaj.TestPlatform;
 import org.luaj.lib.BaseLib;
 import org.luaj.vm.LClosure;
+import org.luaj.vm.LDouble;
+import org.luaj.vm.LInteger;
 import org.luaj.vm.LPrototype;
 import org.luaj.vm.LValue;
 import org.luaj.vm.LuaState;
@@ -85,4 +87,24 @@ public class SimpleTests extends TestCase {
 		String s = "print( 1 == b and b )\n";
 		doTest( s );
 	}
+	
+	private static final int [] samehash = { 0, 1, -1, 2, -2, 4, 8, 16, 32, Integer.MAX_VALUE, Integer.MIN_VALUE };
+	private static final double [] diffhash = { .5, 1, 1.5, 1, .5, 1.5, 1.25, 2.5 };
+	
+	public void testDoubleHashCode() {
+		for ( int i=0; i<samehash.length; i++ ) {
+			LInteger j = LInteger.valueOf(samehash[i]);
+			LDouble d = new LDouble(samehash[i]);
+			int hj = j.hashCode();
+			int hd = d.hashCode();
+			assertEquals(hj, hd);
+		}
+		for ( int i=0; i<diffhash.length; i+=2 ) {
+			LDouble c = new LDouble(diffhash[i+0]);
+			LDouble d = new LDouble(diffhash[i+1]);
+			int hc = c.hashCode();
+			int hd = d.hashCode();
+			assertTrue("hash codes are same: "+hc,hc!=hd);
+		}
+	}
 }