From 039babddf532c918ae3f0ac5360e85e7ba5b3052 Mon Sep 17 00:00:00 2001
From: Adrien Grand <jpountz@gmail.com>
Date: Thu, 16 Aug 2018 11:53:01 +0200
Subject: [PATCH] CharArraysTests: Fix test bug.

---
 .../test/java/org/elasticsearch/common/CharArraysTests.java  | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libs/core/src/test/java/org/elasticsearch/common/CharArraysTests.java b/libs/core/src/test/java/org/elasticsearch/common/CharArraysTests.java
index 64b1ecd1f8a..9283283ab08 100644
--- a/libs/core/src/test/java/org/elasticsearch/common/CharArraysTests.java
+++ b/libs/core/src/test/java/org/elasticsearch/common/CharArraysTests.java
@@ -55,7 +55,10 @@ public class CharArraysTests extends ESTestCase {
         assertTrue(CharArrays.charsBeginsWith(prefix, prefixedValue));
 
         final String modifiedPrefix = randomBoolean() ? prefix.substring(1) : prefix.substring(0, prefix.length() - 1);
-        final char[] nonMatchingValue = modifiedPrefix.concat(randomAlphaOfLengthBetween(0, 12)).toCharArray();
+        char[] nonMatchingValue;
+        do {
+            nonMatchingValue = modifiedPrefix.concat(randomAlphaOfLengthBetween(0, 12)).toCharArray();
+        } while (new String(nonMatchingValue).startsWith(prefix));
         assertFalse(CharArrays.charsBeginsWith(prefix, nonMatchingValue));
         assertTrue(CharArrays.charsBeginsWith(modifiedPrefix, nonMatchingValue));
     }