---- On Thu, 28 Mar 2019 18:53:41 +0100 Hans Hagen
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
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