src/java.base/share/classes/java/io/PushbackInputStream.java

@@ -87,10 +87,13 @@
      * @exception IllegalArgumentException if {@code size <= 0}
      * @since  1.1
      */
     public PushbackInputStream(InputStream in, int size) {
         super(in);
+        if (in == null) {
+            throw new NullPointerException();
+        } 
         if (size <= 0) {
             throw new IllegalArgumentException("size <= 0");
         }
         this.buf = new byte[size];
         this.pos = size;