(fmt) MissingFormatArgumentException.getFormatSpecifier() incorrect return value

The following test program illustrates that the format specifier returned
by MissingFormatArgumentException.getFormatSpecifier() does not correspond
to the one in the original format string as required by specification.
In fact, the returned value isn't even a syntactically valid format specifier.

==========$ cat -n T.java
     1 import java.util.*;
     2 class T {
     3 public static void main(String[] args) {
     4 String spec = "%1$5.3s";
     5 try {
     6 String s2 = String.format(spec);
     7 } catch (MissingFormatArgumentException ex) {
     8 if (!ex.getFormatSpecifier().equals(spec))
     9 throw new Error(ex.getFormatSpecifier());
    10 System.out.println("passed");
    11 }
    12 }
    13 }
==========$ /usr/j2sdk1.5.0/bin/javac T.java
==========$ /usr/j2sdk1.5.0/bin/java T
Exception in thread "main" java.lang.Error: 1$5.3s
        at T.main(T.java:9)
==========$