OpenJDK crash in memcpy

[Bill Zaumen]

Stacktrace and error messages:

Exception in thread "Thread-18" java.lang.NullPointerException
 at SimpleJTextPane.append(SimpleJTextPane.java:194)
 at ThumbnailConsole.append(ThumbnailConsole.java:63)
 at ErrorMessage.display(ErrorMessage.java:57)
 at Gui$18$9.stopProgress(Gui.java:1525)
 at Gui$14.run(Gui.java:1084)
 at java.lang.Thread.run(Thread.java:636)
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007f042f796d2a, pid=10163, tid=139655713048320
#
# JRE version: 6.0_20-b20
# Java VM: OpenJDK 64-Bit Server VM (19.0-b09 mixed mode linux-amd64 compressed oops)
# Derivative: IcedTea6 1.9.5
# Distribution: Ubuntu 10.10, package 6b20-1.9.5-0ubuntu1
# Problematic frame:
# C [libc.so.6+0x86d2a] memcpy+0x29a

The code was the following (I suspect that the argument to the append method was null) -
it was supposed to the the results of e.getMessage() and I had been testing a "cancel"
button. The interrupt was apparently caught while updating a progress bar - using a
method

       public void stopProgress() {
     SwingUtilities.invokeAndWait
         (new Runnable() {
          public void run() {
       pbar.setEnabled(false);
       pbar.setForeground
           (pbarFG);
          }
      });
        }
    } catch (Exception e) {
       ErrorMessage.display(e.getMessage());
    }

ErrorMessage.display(arg) is defined by
    static public void display(String msg) {
 try {
     err.append(msg);
     err.append("\n");
 } catch (IOException e) {
 }
    }

and err was set to a console implementing the Appendable interface (so I could use System.err or
a text pane to log the messages. The text pane method is:

public Appendable append(CharSequence csq) {
 try {
     Document doc = getDocument();
     String str = csq.toString();
     doc.insertString(doc.getLength(), str, aset);
 } catch (BadLocationException e) {
     // This should never happen due use of doc.getLength()
     throw new RuntimeException("bad location exception");
 }
 return (Appendable) this;
    }