Merge pull request functionaljava#112 from xuwei-k/Rand-standard-overflow

mperry · mperry · commit a917ecf32bd6 · 2015-03-22T19:51:19.000+10:00
avoid overflow
diff --git a/core/src/main/java/fj/test/Rand.java b/core/src/main/java/fj/test/Rand.java
@@ -130,9 +130,14 @@ public F<Integer, F<Integer, Integer>> f(final Option<Long> seed) {
         public F<Integer, Integer> f(final Integer from) {
           return new F<Integer, Integer>() {
             public Integer f(final Integer to) {
-              final int f = min(from, to);
-              final int t = max(from, to);
-              return f + seed.map(fr).orSome(new Random()).nextInt(t - f + 1);
+              if(from == to){
+                return from;
+              }else{
+                final int f = min(from, to);
+                final int t = max(from, to);
+                final int x = Math.abs(t - f);
+                return f + seed.map(fr).orSome(new Random()).nextInt(x == Integer.MIN_VALUE ? Integer.MAX_VALUE : x);
+              }
             }
           };
         }
