[Toybox] config2help SEGFAULT

[Jazzoo Watchman]

Hello all,
Hope this finds you well.

Trying to run config2help it segfaults.

Pulling the source from Toybox and building with
  gcc -0 -g -Wall

That too segfaults so I think I have the latest version (the source seems
to be mostly contained in a single file scripts/config2help.c).

Google(ing) turned up many hits of fairly recent (circa 2018+)
conversations on or about this same complaint.

Digging into the logic of the code, it seems there may be some cruft/age to
the logic and some mishandling of pointer use AFTER free (as shown by
valgrind).  In "some" aforementioned Google(ing) complaints seemed so stem
from an update of their glibc.  I can attest to the same as my builds were
going  smoothly until I did an apt update; apt upgrade .

My point.

1.)
Is the latest source (hopefully) with a fix for the "use after free"
segfault in "
https://github.com/landley/toybox/blob/master/scripts/config2help.c"

2.)
Following the code in 1.) it seems that some of the logic may be more
complex than the input would suggest.

The code inspecting the generated "sym" list while looping through the
entries in ".config" and setting sym->enabled ... indicates to me that
".config" controls which "processed" "symbols" get spit-out as "#defined
HELPXXX".

Is that true and or intended?

The flow seems to indicate that multiple "symbols" of the same "name"
may/do exist over multiple Config.in (and "sourced") files; and
"duplicates" need/should to be "collated".  In practice; I haven't seen
"duplicate" "symbols" and wonder if mashing "duplicates" together wouldn't
lead to probable error/nonsense.

3.)
If the above are/is true; would a rewrite with less "dependencies" and a
"clean" valgrind run be at-all welcome?

In closing, am I just lost in the woods?  If so, could someone spin me
around and nudge me in the correct direction?

Thanks for your attention,


James
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