False positive due to character array on stack with initialiser

[Daniel Egger]

Hi guys,

I discovered a false positive with some (ancient) use of an initialiser to initialise a character array on the stack to an empty string.

I tried to create a Trac account to create a ticket but somehow didn't receive the email.

Here's a demo program to show the warning:

#include <stdio.h>

int main (int argc, char **argv)
{
        char str[6] = "\0";
        unsigned short port = 65535;

        snprintf (str, sizeof (str), "%hu", port);
}

The warning is:

[test.c:8]: (error) Buffer is accessed out of bounds.

The only way to removing the warning is to get rid of the "\0".

[antred]

The false positive should still be fixed, but why not just do

char str[6] = {};

[Mr. X]

Fixed by:
https://github.com/danmar/cppcheck/commit/644a2163945340d2df6f4390781730bb74238567