Avoid NullPointerException in ProxyInputStream.mark(int) when the

underlying input stream is null

Author: garydgregory

src/changes/changes.xml

@@ -66,6 +66,7 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">AutoCloseInputStream(InputStream) uses ClosedInputStream.INSTANCE when its input is null.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in ProxyInputStream.available() when the underlying input stream is null.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in ProxyInputStream.markSupported() when the underlying input stream is null.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NullPointerException in ProxyInputStream.mark(int) when the underlying input stream is null.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">BufferedFileChannelInputStream.available() returns 0 before any reads.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">BufferedFileChannelInputStream.available() should return 0 when the stream is closed instead of throwing an exception.</action>      
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">CharSequenceInputStream.available() should return 0 after the stream is closed.</action>

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

@@ -186,7 +186,9 @@ boolean isClosed() {
      */
     @Override
     public synchronized void mark(final int readLimit) {
-        in.mark(readLimit);
+        if (in != null) {
+            in.mark(readLimit);
+        }
     }
 
     /**

src/test/java/org/apache/commons/io/input/ProxyInputStreamTest.java

@@ -134,6 +134,19 @@ protected void testEos(final T inputStream) {
         // empty
     }
 
+    //@Test
+    public void testMarkOnNull() throws IOException {
+        try (T inputStream = createFixture(null)) {
+            inputStream.mark(1);
+            inputStream.setIn(createFixture());
+            inputStream.mark(1);
+            IOUtils.toByteArray(inputStream);
+            inputStream.mark(1);
+            inputStream.setIn(null);
+            inputStream.mark(1);
+        }
+    }
+
     @Test
     public void testMarkSupported() throws IOException {
         try (T inputStream = createFixture()) {