memory leak changing IGNORECASE (gawk 3.1.1)

[Ian D]

I have a complex script that runs through a series of regex tests for every
record read.  The regex expressions are parsed from a config file and stored
in variables.  For each expression tested, IGNORECASE is set to a variable
that is 0 or 1 depending on whether the match should ignore case.  After the
test, IGNORECASE is set back to 0.  When running this script, memory usage
continually increases until swap space is exhausted.  I then commented out
the first IGNORECASE and retained the second, and I have the same problem.
Here is a snippet, inside of a for loop (for each fpatt in an array), which
is invoked for every record read.

                        #IGNORECASE=icase
                        fieldok=fnot ? ($fnum !~ fpatt) : ($fnum ~ fpatt)
                        IGNORECASE=0

But if you comment out IGNORECASE=0, the memory is static, even for millions
of input records.

The error I get is "gawk: cmd. line:139: (FILENAME=- FNR=312911) fatal:
Memory exhausted."  I then modified source and determined that the line
printing this error is dfa.c:193.  Line 139 is the IGNORECASE=0 line.

I have seen references in the ChangeLog similar to this problem, but
apparently it isn't fixed.  Any ideas on how to fix this is appreciated.

Thanks,
Ian