Revert add and substract tests, they are correct

Author: buchholz

src/main/java/org/javamoney/moneta/FastMoney.java

@@ -368,11 +368,6 @@ private long addExact(long num1, long num2) {
         boolean pos = num1>0 && num2 >0;
         boolean neg = num1<0 && num2 <0;
         long exact = num1 + num2;
-
-//        if((num1 ^ num2) >= 0 & (num1 ^ exact) < 0){
-//        	throw new ArithmeticException("Long evaluation overflow.");
-//        }
-        
         if(pos && exact <=0){
             throw new ArithmeticException("Long evaluation positive overflow.");
         }
@@ -481,7 +476,7 @@ private long multiplyExact(long num1, long num2) {
 
         long exact = num1 * num2;
 
-        // very expensive - this check is only executed in special cases
+        // very expensive - this check is only executed in edge cases
         // zero check is not needed, see above
         if( exact / num1 != num2 ) {
         	throw new ArithmeticException("overflow");
@@ -529,14 +524,14 @@ private long subtractExact(long num1, long num2) {
         if(num1==num2){
             return 0;
         }
-//        boolean pos = num1>num2;
+        boolean pos = num1>num2;
         long exact = num1 - num2;
-//        if(pos && exact <=0){
-//            throw new ArithmeticException("Long evaluation negative overflow.");
-//        }
-//        if(!pos && exact >=0){
-//            throw new ArithmeticException("Long evaluation positive overflow.");
-//        }
+        if(pos && exact <=0){
+            throw new ArithmeticException("Long evaluation negative overflow.");
+        }
+        if(!pos && exact >=0){
+            throw new ArithmeticException("Long evaluation positive overflow.");
+        }
         return exact;
     }
 

src/test/java/org/javamoney/moneta/FastMoneyTest.java

@@ -290,9 +290,11 @@ public void testAdd(){
         assertNotNull(moneyResult);
         assertEquals(11d, moneyResult.getNumber().doubleValue(), 0d);
 
+        // 87978089321359 + 4866358678300 = 92844447999659 > 92233720368547.75807
+
         // This example produce a false positive in the old version
-        money1 = FastMoney.of(44474249632057L, EURO);
-        money2 = FastMoney.of(72913073429160L, EURO);
+        money1 = FastMoney.of(87978089321359L, EURO);
+        money2 = FastMoney.of(4866358678300L, EURO);
 
         try {
             moneyResult = money1.add(money2); 
@@ -301,7 +303,7 @@ public void testAdd(){
             // should happen
         }
 
-        // check greates    92233720368547.75807 value
+        // check greates FM 92233720368547.75807 value
         long fastMoneyMax = 92233720368547L;
 		FastMoney money3 = FastMoney.of(fastMoneyMax, "CHF");