CLJ-1225: Correct (quot (bigint Long/MIN_VALUE) -1N) answer

Signed-off-by: Stuart Halloway <[email protected]>

Author: jafingerhut

src/jvm/clojure/lang/BigInt.java

@@ -160,6 +160,8 @@ public BigInt multiply(BigInt y) {
 
 public BigInt quotient(BigInt y) {
     if ((bipart == null) && (y.bipart == null)) {
+        if (lpart == Long.MIN_VALUE && y.lpart == -1)
+            return BigInt.fromBigInteger(this.toBigInteger().negate());
         return BigInt.valueOf(lpart / y.lpart);
     }
     return BigInt.fromBigInteger(this.toBigInteger().divide(y.toBigInteger()));

test/clojure/test_clojure/numbers.clj

@@ -300,6 +300,14 @@
   (is (thrown? ArithmeticException (/ 2 0)))
   (is (thrown? IllegalArgumentException (/))) )
 
+(deftest test-divide-bigint-at-edge
+  (are [x] (= x (-' Long/MIN_VALUE))
+       (/ Long/MIN_VALUE -1N)
+       (/ (bigint Long/MIN_VALUE) -1)
+       (/ (bigint Long/MIN_VALUE) -1N)
+       (quot Long/MIN_VALUE -1N)
+       (quot (bigint Long/MIN_VALUE) -1)
+       (quot (bigint Long/MIN_VALUE) -1N)))
 
 ;; mod
 ;; http://en.wikipedia.org/wiki/Modulo_operation