[Gawkextlib-users] gawkextlib xml on gawk-5.2.1

[Daniel P. <do...@me...>]

Is gawkextlib xml expected to work with gawk 5.2.1 (API 3.2), with the new
AWK_BOOL?

It works as expected with awk 5.1.1, and with all earlier versions going back to
4.1.3. I've been using it regularly since 2017.

But with 5.2.1 I'm seeing anomalous behavior where empty xml elements (e.g.
<doi></doi>) are evaluating as true even though they string-equal "".

In connection with that empty xml field, gawk 5.2.1 crashes with

gawk: ../mkbib.awk:1142: (FILENAME=buzsaki_2003_EEG_source.xml FNR=173) fatal: internal error: file eval.c, line 1358: unexpected parameter type Node_illegal

If I build with sanitizer, I see concat_exp() doing a double-free of an arg that
was earlier freed by r_interpret().

I did a whole slew of experiments to try to understand what's happening, but
it's a large and tricky code base.  It seems to have something to do with
Node_var appearing where usually Node_val is, but I was quickly in over my head.

libgawkextlib and xml.so were both built with gawk-5.2.1 installed.  I tried
with old release code and with the latest git sources -- same result, as above.

If it's useful I can share buzsaki_2003_EEG_source.xml and even the script
that's crashing on 5.2.1.