Bug 383403 – chktex detects wrong file names when following \input commands

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Edgar Gonzàlez i Pellicer 2011-09-17 19:15:45 UTC]

After upgrading glibc, I found that chktex was unable to follow the names of \input commands, because it misdetected the name between the {} delimiter pair. I tried to re-emerge chktex, but to no success.

Reproducible: Always

Steps to Reproduce:
Run chktex on a file which contains an \input command.


Actual Results:  
For the sample files main.tex:

\documentclass{article}
\input{part}

and part.tex:

\begin{document}
A \dots B
\end{document}

the output of:

$ chktex main.tex

is:

ChkTeX v1.6.4 - Copyright 1995-96 Jens T. Berger Thielemann.

chktex: WARNING -- Unable to open the TeX file `patt'.
Warning 27 in main.tex line 3: Could not execute LaTeX command.
\input{part}  
^^^^^^
No errors printed; One warning printed; No user suppressed warnings printed.


Expected Results:  
The output should be:

ChkTeX v1.6.4 - Copyright 1995-96 Jens T. Berger Thielemann.

Warning 1 in part.tex line 2: Command terminated with space.
A \dots B  
       ^
No errors printed; One warning printed; No user suppressed warnings printed.


On line 221 of file FindErrs.c in the chktex-1.6.4 sources, the following call is performed:

strcpy(OrigDest, OrigDest + 1);

According to the man page of strcpy(3), the src and dst strings should not overlap, so the results are undefined. When I emerged glibc to version 2.12.2, the bug actually occurred.

I have replaced the call for an alternative:

ShiftLeftOne(OrigDest);

defined as

static void ShiftLeftOne(char *Buf)
{
    char *P;

    for (P = Buf + 1; *P; ++P)
      *(P - 1) = *P;
    *(P - 1) = '\0';
}

I will now attach the patch file and the ebuild to fix it.

[Comment 1 Edgar Gonzàlez i Pellicer 2011-09-17 19:16:58 UTC]

Created attachment 286819 [details, diff]
Fix to the file FindErr.c, to replace an undefined call to strcpy

See bug report for a description of the detected bug, and my proposal to fix it.

[Comment 2 Edgar Gonzàlez i Pellicer 2011-09-17 19:29:55 UTC]

Created attachment 286821 [details, diff]
Fix to the file FindErr.c, to replace an undefined call to strcpy

My excuses! I attached the wrong patch format!

[Comment 3 Edgar Gonzàlez i Pellicer 2011-09-17 19:32:08 UTC]

Created attachment 286823 [details, diff]
Ebuild which includes the attached patch.

After

ebuild chktex-1.6.4-r1 merge

The compiled chktex no longer shows the bug.

[Comment 4 Edgar Gonzàlez i Pellicer 2011-09-17 19:42:16 UTC]

BTW, I also filed a bug report in the chktex project page:

https://savannah.nongnu.org/bugs/index.php?34322

[Comment 5 Edgar Gonzàlez i Pellicer 2011-09-17 20:34:22 UTC]

Created attachment 286825 [details, diff]
Fix to the file FindErr.c, to replace an undefined call to strcpy

The patched code I had previously attached could produce a segfault under certain conditions. This updated patch should fix it.

[Comment 6 Alexis Ballier 2015-04-29 15:10:05 UTC]

should be fixed in 1.7.3 then