Re: Texinfo 7.0.93 pretest available

[Eli Zaretskii]

> Date: Sun, 08 Oct 2023 12:41:19 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: bug-texinfo@gnu.org
> 
>   Starting program: d:\usr\Perl\bin\perl.exe ../tp/texi2any.pl info-stnd.texi
> 
>   Program received signal SIGSEGV, Segmentation fault.
>   0x692a6fc6 in getdelim ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   (gdb) bt
>   #0  0x692a6fc6 in getdelim ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #1  0x6928c993 in next_text ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #2  0x6928ba6a in parse_texi ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #3  0x6928bc58 in parse_texi_document ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #4  0x692840d0 in parse_file ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #5  0x6928219c in XS_Texinfo__Parser_parse_file ()
>      from D:\gnu\texinfo-7.0.93\tp\Texinfo\XS\.libs\Parsetexi.dll
>   #6  0x66c8b8bb in perl520!Perl_find_runcv () from 
> d:\usr\Perl\bin\perl520.dll
> 
> Source code information is not available in the debug info, but from
> looking at the disassembly of the code, I see that getdelim (from
> Gnulib) calls realloc, which resolves to the default realloc
> implementation of the MinGW libc.  Isn't that dangerous, given that at
> least some code in the extensions uses the Perl's malloc/free
> implementation?

Sorry, I was mistaken: the Gnulib getdelim is not used here.  Instead,
this build uses the MinGW implementation of getdelim, and that one has
a subtle bug, which rears its ugly head because the second argument to
getline, here:

          status = getline (&line, &n, input_file);

is not initialized to any value.  The simple fix below avoids the
crash and allows the build to run to completion:

--- tp/Texinfo/XS/parsetexi/input.c~    2023-08-14 23:12:04.000000000 +0300
+++ tp/Texinfo/XS/parsetexi/input.c     2023-10-08 14:35:33.142000000 +0300
@@ -395,7 +395,7 @@ next_text (ELEMENT *current)
 {
   ssize_t status;
   char *line = 0;
-  size_t n;
+  size_t n = 120;
   FILE *input_file;
 
   if (input_pushback_string)