Handle edge case in arbitrary-precision substraction. refs #690

Signed-off-by: Stuart Halloway <stu@Orolo.local>
ambakshi · Jan 6, 2011 · 9506ca6 · 9506ca6
1 parent 16eef0b
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diff --git a/src/jvm/clojure/lang/Numbers.java b/src/jvm/clojure/lang/Numbers.java
@@ -167,7 +167,9 @@ static public Number minus(Object x, Object y){
 
 static public Number minusP(Object x, Object y){
 	Ops yops = ops(y);
-	return ops(x).combine(yops).addP((Number)x, yops.negateP((Number)y));
+	Number negativeY = yops.negateP((Number) y);
+	Ops negativeYOps = ops(negativeY);
+	return ops(x).combine(negativeYOps).addP((Number)x, negativeY);
 }
 
 static public Number multiply(Object x, Object y){

diff --git a/test/clojure/test_clojure/numbers.clj b/test/clojure/test_clojure/numbers.clj
@@ -481,3 +481,9 @@ Math/pow overflows to Infinity."
   (is (= (bigint (/ 100000000000000000000 3)) 33333333333333333333))
   (is (= (long 10000000000000000000/3) 3333333333333333333)))
 
+(deftest test-arbitrary-precision-subtract
+  (are [x y] (= x y)
+       9223372036854775808N (-' 0 -9223372036854775808)
+       clojure.lang.BigInt  (class (-' 0 -9223372036854775808))
+       java.lang.Long       (class (-' 0 -9223372036854775807))))
+