Fix intermittent test failure spotted during some refactoring.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc8.5.x/trunk@1774166 13f79535-47bb-0310-9956-ffa450edef68

java/org/apache/coyote/http11/Http11InputBuffer.java

@@ -296,12 +296,16 @@ void recycle() {
     void nextRequest() {
         request.recycle();
 
-        // Copy leftover bytes to the beginning of the buffer
-        if (byteBuffer.remaining() > 0 && byteBuffer.position() > 0) {
-            byteBuffer.compact();
+        if (byteBuffer.position() > 0) {
+            if (byteBuffer.remaining() > 0) {
+                // Copy leftover bytes to the beginning of the buffer
+                byteBuffer.compact();
+                byteBuffer.flip();
+            } else {
+                // Reset position and limit to 0
+                byteBuffer.position(0).limit(0);
+            }
         }
-        // Always reset pos to zero
-        byteBuffer.limit(byteBuffer.limit() - byteBuffer.position()).position(0);
 
         // Recycle filters
         for (int i = 0; i <= lastActiveFilter; i++) {

webapps/docs/changelog.xml

@@ -83,6 +83,11 @@
         when configured with an address of <code>0.0.0.0</code> or
         <code>::</code>. (markt)
       </fix>
+      <fix>
+        Correct a regression in the refactoring to make wider use of
+        <code>ByteBuffer</code> that caused an intermittent failure in the unit
+        tests. (markt)
+      </fix>
     </changelog>
   </subsection>
   <subsection name="Web Applications">