add a test that could generate negative with the old code.

Signed-off-by: Ken McCracken <ken.mccracken@here.com>

Author: kenmccracken

here-oauth-client/src/main/java/com/here/account/oauth2/retry/Socket5xxExponentialRandomBackoffPolicy.java

@@ -52,6 +52,7 @@ public boolean shouldRetry(RetryContext retryContext) {
     public int getNextRetryIntervalMillis(RetryContext retryContext){
         int retryCount = retryContext.getRetryCount();
         int factor = Math.min(1 << (Math.min(retryCount, 30)), maxRetryFactor);
-        return  retryIntervalMillis * ThreadLocalRandom.current().nextInt(factor);
+        long value = ((long) retryIntervalMillis) * ThreadLocalRandom.current().nextInt(factor);
+        return (int) Math.min(Integer.MAX_VALUE, value);
     }
 }

here-oauth-client/src/test/java/com/here/account/oauth2/retry/Socket5xxExponentialRandomBackoffPolicyTest.java

@@ -22,6 +22,18 @@ public void setUp() {
                         maxRetryFactor);
     }
 
+    @Test
+    public void test_largeRetryCount_notNegative() {
+        for (int j = 0; j < 10; j++) {
+            RetryContext retryContext = new RetryContext();
+            for (int i = 0; i < 40; i++) {
+                retryContext.incrementRetryCount();
+                int nextRetryIntervalMillis = socket5xxExponentialRandomBackoffPolicy.getNextRetryIntervalMillis(retryContext);
+                assertTrue("i=" + i + ", retryContext.getRetryCount()=" + retryContext.getRetryCount() + ", nextRetryIntervalMillis was negative " + nextRetryIntervalMillis, nextRetryIntervalMillis >= 0);
+            }
+        }
+    }
+
     @Test
     public void test_shouldRetry() {
         HttpProvider.HttpResponse httpResponse = Mockito.mock(HttpProvider.HttpResponse.class);