FULL PRODUCT VERSION :
java version "1.4.2_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_01-b06)
Java HotSpot(TM) Client VM (build 1.4.2_01-b06, mixed mode)

FULL OS VERSION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
  From http://java.sun.com/j2se/1.4.2/docs/api/java/text/DecimalFormat.html:

public StringBuffer format(long number,
                           StringBuffer result,
                           FieldPosition fieldPosition)
Format a long to produce a string.
Specified by:
format in class NumberFormat

Parameters:
number - The long to format
result - where the text is to be appended
fieldPosition - On input: an alignment field, if desired. On output: the offsets of the alignment field.
Returns:
The formatted number string

In spite of what the documentation says about fieldPosition, the alignment field seems to be ignored.



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
(See test case)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
B,E 0,0
B,E 10,23
          1,234,567,890
B,E 10,23
ACTUAL -
B,E 0,0
B,E 10,23
1,234,567,890
B,E 0,13


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.text.DecimalFormat;
import java.text.FieldPosition;
import java.text.NumberFormat;
public class TestFormat{
public static void main(String[] args)
{
StringBuffer sb = new StringBuffer();
DecimalFormat df = new DecimalFormat();
FieldPosition fp = new FieldPosition(NumberFormat.INTEGER_FIELD);
System.out.println("B,E "+fp.getBeginIndex()+","+fp.getEndIndex());//B,E 0,0
fp.setBeginIndex(10); fp.setEndIndex(23);
System.out.println("B,E "+fp.getBeginIndex()+","+fp.getEndIndex());//B,E 10,23
df.format(1234567890L,sb,fp);// Use FieldPosition to affect output
System.out.println(sb); //1,234,567,890 - no leading spaces
System.out.println("B,E "+fp.getBeginIndex()+","+fp.getEndIndex());//B,E 0,13
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
[Ignore the documentation!]