---- On Thu, 28 Mar 2019 18:53:41 +0100 Hans Hagen <j.ha...@xs4all.nl> wrote
----
> On 3/28/2019 3:57 PM, Marcel Krüger wrote:
> > Hi,
> >
> > there are multiple issues memory issues in tprint:
> >
> > If the buffer passed to tprint only contains of to be escaped characters,
> > the `xmalloc(strlen(sss)*3)` is too small: The final `\0` can not be
> > written, so this causes a write into unallocated memory.
> > If t_flush_buffer is called for such a buffer at the last position, there
> > is an additional `\n` written, so `xmalloc(strlen(sss)*3+2)` is needed.
> >
> > Additionally, the test `if (*buffer)` is used to test if there is
> > something to print left. If the parameter is empty, `*buffer` is never
> > written, so valgrind complains about `if (*buffer)` depending on
> > uninitialized memory. Instead, `if (i)` can be used: `i` is the length of
> > the written part of the buffer, so `i==0` iff there is nothing to write.
> >
> > A related problem is with `max_print_line`:
> > If the point where the line should be broken falls inside the escape
> > sequence of an escaped character,
> > the line limit is ignored.
> > This can be fixed by adding
> >
> > if (term_offset+2>=max_print_line) {
> > wterm_cr();
> > term_offset=0;
> > }
> >
> > as in `wterm_char` also in tprint above `buffer[i++] = '^';`.
> >
> > A full patch fixing all three issues is attached.
> Can you give a plain tex example where the fault happens? Normally the
> max line length kicks in (3 chars) before such an overflow.
Try
\let\3\relax
\directlua{
texio.write'\3'% Only to be escaped characters -> valgrind complains about
write into unallocated memory
texio.write_nl''
for i=1,kpse.var_value'max_print_line'-3 do texio.write'.' end
texio.write'\3' % Here LuaTex writes 2 and not just 1 byte after it's
allocated memory area
for i=1,kpse.var_value'max_print_line'-1 do texio.write'.' end
texio.write'\3' % The line break would fall inside of the escape sequence ->
Line limit ignored
for i=1,2*kpse.var_value'max_print_line' do texio.write'.' end % This should
normally not fit into one line
}
\bye
>
> (btw, nothing fundamental will change in the texlive code freeze frame)
Right, it isn't urgent anyway, I just wanted to clean up my valgrind output...
Best regards
Marcel Krüger
>
> Hans
>
> -----------------------------------------------------------------
> Hans Hagen | PRAGMA ADE
> Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
> tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
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