libgcj/5671: verify.cc problem merging local variables

[toddastock@yahoo.com]

>Number:         5671
>Category:       libgcj
>Synopsis:       verify.cc problem merging local variables
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Feb 12 10:26:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     
>Release:        3.1 20020211 (experimental)
>Organization:
>Environment:
System: Linux escher 2.4.9-21 #1 Thu Jan 17 14:16:30 EST 2002 i686 unknown
Architecture: i686

	
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ./configure --enable-threads=posix --prefix=/home/tstock/local --disable-shared --enable-languages=c++,java
>Description:
	During the merging of the local variables if the previous variable is an interface then running through the superclasses leads you directly to NULL eventually thus causing a segmentation fault.
>How-To-Repeat:
import java.io.*;
import java.util.*;

public class Test
  {

  public static void main(String[] args)
    {
      new Test().doit();
    }

  public void doit( )
    {

      String x = "abc";
      try
      {
        Properties props = new Properties();
        Enumeration enum = props.propertyNames();
      }
      catch( Exception e )
      {
      }
      String _x = "def";
      try
      {
        Properties props = new Properties();
        Enumeration enum = props.propertyNames();
      }
      catch( Exception e )
      {
      }
    }

  }
>Fix:
Index: libjava/verify.cc
===================================================================
RCS file: /cvsroot/gcc/gcc/libjava/verify.cc,v
retrieving revision 1.35
diff -r1.35 verify.cc
679c679
< 		  while (true)
---
> 		  while (true && k!=NULL)
686a687,692
> 		  if( k == NULL )
> 		    {
> 		      *this = old_type;
> 		      changed = true;
> 		    }
> 		  else
>Release-Note:
>Audit-Trail:
>Unformatted: