8281183: RandomGenerator:NextDouble() default behavior partially fixe…

…d by JDK-8280950 Backport-of: 77b0240d44fd356711d75bc241e198f6f89ada8f
openjdk · Feb 9, 2022 · 6202ea5 · 6202ea5 · openjdk-notifier · Feb 9, 2022
1 parent e1dfd9f
commit 6202ea5
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Showing 2 changed files with 7 additions and 4 deletions.
diff --git a/src/java.base/share/classes/jdk/internal/util/random/RandomSupport.java b/src/java.base/share/classes/jdk/internal/util/random/RandomSupport.java
@@ -677,7 +677,7 @@ public static double boundedNextDouble(RandomGenerator rng, double bound) {
         double r = rng.nextDouble();
         r = r * bound;
         if (r >= bound)  // may need to correct a rounding problem
-            r = Math.nextDown(r);
+            r = Math.nextDown(bound);
         return r;
     }
 

diff --git a/test/jdk/java/util/Random/RandomNextDoubleBoundary.java b/test/jdk/java/util/Random/RandomNextDoubleBoundary.java
@@ -24,7 +24,7 @@
 /*
  * @test
  * @summary Verify nextDouble stays within range
- * @bug 8280550 8280950
+ * @bug 8280550 8280950 8281183
  */
 
 import java.util.SplittableRandom;
@@ -79,8 +79,11 @@ public long nextLong() {
         };
         double value = rg.nextDouble(origin, bound);
 
-        assertTrue(value >= origin);
-        assertTrue(value < bound);
+        if (bound > 0) {
+            value = rg.nextDouble(bound); // Equivalent to nextDouble(0.0, bound)
+            assertTrue(value >= 0.0);
+            assertTrue(value < bound);
+        }
     }
 
     public static void assertTrue(boolean condition) {