Google Code-in

We recently discovered a small flaw in one of our code sections, and we'd like to invite you to take a look at the function in question, and try to find the mistake.

The function which contains the bug is parsedelay.

This function parses a given parameter (par), and should check if a positive or negative delay should be set in the options.

We expect that you check the code, and send us a reply with how we can fix the issue.

The code for this function is as follows:

int parsedelay (struct ccx_s_options *opt, char *par)
{
    int sign = 0;
    char *c = par;
    while (*c)
    {
        if (*c == '-' || *c == '+')
        {
            if (c != par) // Sign only at the beginning
                return 1;
            if (*c == '-')
                sign = 1;                
            if (*c == '+')
                sign = 1;                
        }
        else
        {
            if (!isdigit (*c))
                return 1;
            opt->subs_delay = opt->subs_delay*10 + (*c-'0');
        }
        c++;
    }
    if (sign)
        opt->subs_delay = -opt->subs_delay;
    return 0;
}

Note: in order to find this bug you don't need to run or compile anything. Just thinking logically while going over the code should be sufficient to find the one bug we're after.