re PR libgcj/1913 (reading closed streams throws NullPointerException, not IOException)

	From paul@dawa.demon.co.uk.  Fix for PR libgcj/1913:
	* java/io/InputStreamReader.java (ready, read): Throw IOException
	if stream has been closed.

From-SVN: r39553

libjava/ChangeLog

+2001-02-08  Tom Tromey  <tromey@redhat.com>
+
+	From paul@dawa.demon.co.uk.  Fix for PR libgcj/1913:
+	* java/io/InputStreamReader.java (ready, read): Throw IOException
+	if stream has been closed.
+
 2001-02-08  Joseph S. Myers  <jsm28@cam.ac.uk>
 
 	* README, gij.cc, java/lang/natClass.cc, java/lang/natSystem.cc:

libjava/java/io/InputStreamReader.java

-/* Copyright (C) 1998, 1999  Free Software Foundation
+/* Copyright (C) 1998, 1999, 2001  Free Software Foundation
 
    This file is part of libgcj.
 
@@ -71,6 +71,9 @@ public class InputStreamReader extends Reader
   {
     synchronized (lock)
       {
+	if (in == null)
+	  throw new IOException("Stream closed");
+
 	if (wpos < wcount)
 	  return true;
 	if (work == null)
@@ -102,6 +105,9 @@ public class InputStreamReader extends Reader
   {
     synchronized (lock)
       {
+	if (in == null)
+	  throw new IOException("Stream closed");
+
 	int wavail = wcount - wpos;
 	if (wavail > 0)
 	  {
@@ -136,6 +142,9 @@ public class InputStreamReader extends Reader
   {
     synchronized (lock)
       {
+	if (in == null)
+	  throw new IOException("Stream closed");
+
 	int wavail = wcount - wpos;
 	if (wavail > 0)
 	  return work[wpos++];