free used incorrectly in api.c

[Gavin Smith]

On Sun, Oct 23, 2022 at 02:17:58PM +0300, Eli Zaretskii wrote:
> So here's the error message I get when Perl crashes:
> 
>   Free to wrong pool 3f5d70 not 50d0190 at 
> ..\..\tp/Texinfo/XS/parsetexi/Parsetexi.pm line 97.
> 
> This hints on a memory allocation problem.  And indeed, Parsetexi.pm
> line 97 does this:
> 
>   reset_parser ();
> 
> And reset_parser calls a bunch of functions from indices.c, which use
> malloc/realloc/free without redirecting them to the Perl allocation
> functions.  I guess we need the dTXH thingy there, but doing so needs
> some Perl includes?  Can you tell me what I need to put at the
> beginning of the file to be able to use dTHX safely in indices.c?
> 
> Or maybe we need something other than dTHX there?
> 
> I see that a lot of other files in tp/Texinfo/XS/parsetexi/ call
> memory allocation functions, but don't have dTHX -- is that safe?

I believe the issue is with calling 'free' inside api.c itself.  It
should be okay inside the other files.  We don't include the Perl
header files everywhere - only in api.c.  We need to move this code
to other files and this should fix the problem.