Bugfix - buffer must always hold at least 'size' bytes

Author: adamretter

src/main/java/org/apache/commons/codec/binary/BaseNCodec.java

@@ -567,7 +567,7 @@ public String encodeToString(final byte[] pArray) {
      */
     protected byte[] ensureBufferSize(final int size, final Context context){
         if (context.buffer == null) {
-            context.buffer = new byte[getDefaultBufferSize()];
+            context.buffer = new byte[Math.max(size, getDefaultBufferSize())];
             context.pos = 0;
             context.readPos = 0;