--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/io/BufferedReader/Fill.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 1998, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+   @bug 4090383
+   @summary Ensure that BufferedReader's read method will fill the target array
+            whenever possible
+ */
+
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.BufferedReader;
+
+
+public class Fill {
+
+    /**
+     * A simple Reader that is always ready but may read fewer than the
+     * requested number of characters
+     */
+    static class Source extends Reader {
+
+        int shortFall;
+        char next = 0;
+
+        Source(int shortFall) {
+            this.shortFall = shortFall;
+        }
+
+        public int read(char[] cbuf, int off, int len) throws IOException {
+            int n = len - shortFall;
+            for (int i = off; i < n; i++)
+                cbuf[i] = next++;
+            return n;
+        }
+
+        public boolean ready() {
+            return true;
+        }
+
+        public void close() throws IOException {
+        }
+
+    }
+
+    /**
+     * Test BufferedReader with an underlying source that always reads
+     * shortFall fewer characters than requested
+     */
+    static void go(int shortFall) throws Exception {
+
+        Reader r = new BufferedReader(new Source(shortFall), 10);
+        char[] cbuf = new char[8];
+
+        int n1 = r.read(cbuf);
+        int n2 = r.read(cbuf);
+        System.err.println("Shortfall " + shortFall
+                           + ": Read " + n1 + ", then " + n2 + " chars");
+        if (n1 != cbuf.length)
+            throw new Exception("First read returned " + n1);
+        if (n2 != cbuf.length)
+            throw new Exception("Second read returned " + n2);
+
+    }
+
+    public static void main(String[] args) throws Exception {
+        for (int i = 0; i < 8; i++) go(i);
+    }
+
+}