IO-211: Pre- and post-processing support for proxied streams

Add null protection as pointed out in IO-242

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@934041 13f79535-47bb-0310-9956-ffa450edef68

Author: jukka

src/java/org/apache/commons/io/input/ProxyInputStream.java

@@ -74,7 +74,7 @@ public int read() throws IOException {
     @Override
     public int read(byte[] bts) throws IOException {
         try {
-            beforeRead(bts.length);
+            beforeRead(bts != null ? bts.length : 0);
             int n = in.read(bts);
             afterRead(n);
             return n;

src/java/org/apache/commons/io/output/ProxyOutputStream.java

@@ -68,7 +68,7 @@ public void write(int idx) throws IOException {
     @Override
     public void write(byte[] bts) throws IOException {
         try {
-            beforeWrite(bts.length);
+            beforeWrite(bts != null ? bts.length : 0);
             out.write(bts);
             afterWrite(bts.length);
         } catch (IOException e) {