bug in PrettyWriter

[Felix S Klock II <pnkfelix at MIT dot EDU>]

Kawa list-

There is a bug in the pretty printing routine; it does not properly
reset the prefix field when it discovers that the prefix needs to be 
lengthened, due to the LHS of the assignment being bound to a local
variable and not the field that was desired. 

Thus, when the array  this.prefix[i]  gets a new value in the code
immediately following this snippet, it throws
ArrayIndexOutOfBoundsException.  A solution is to assign to
this.prefix instead of the local variable prefix.

However, I also fail to understand why the local variable prefix has
been introduced in the first place.  It doesn't seem to serve any
purpose; perhaps it is legacy code.  But I'll let Per explain his
thinking himself.  All I know is that this seems to fix the (fairly
severe) problem for me.

I have not included a test case that exposes the bug, since generating
it requires a fairly deeply nested structure and I haven't figured out
a trivial way to generate such a structure for printing.

Index: gnu/text/PrettyWriter.java
===================================================================
RCS file: /cvs/kawa/kawa/gnu/text/PrettyWriter.java,v
retrieving revision 1.2
diff -u -r1.2 PrettyWriter.java
--- PrettyWriter.java   2001/07/17 19:28:54     1.2
+++ PrettyWriter.java   2001/08/17 23:46:29
@@ -385,7 +385,7 @@
       {
        char[] newPrefix = new char[enoughSpace(prefixLen, column -
prefixLen)];
        System.arraycopy(prefix, 0, newPrefix, 0, current);
-       prefix = newPrefix;
+       this.prefix = newPrefix;
       }
     if (column > current)
       {