This should be fixed, though with a slightly different change than the one you provided.  Thanks for your report.

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.

For instance, 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.


But it 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.


I checked the source code of version 1.6.4 of chktex, and found that on line 221 of file FindErrs.c, 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 upgraded glibc to version 2.12.2, the bug actually occurred.


I include a patch which replaces 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';
}

After recompiling, the bug was solved.