Description Laurent Cruaud 2013-10-21 12:05:56 EDT

The str_fmt_exception() function is based on the vsnprintf().

With Visual, the vsnprintf() could return a negative value -1 when the output was truncated.
According to the Unix man page, it could be the case too, depending on the glibc version.

    while (1) {
        buf = (char *)loc_realloc(buf, len);
        va_start(vaList, fmt);
        n = vsnprintf(buf, len, fmt, vaList);
        va_end(vaList);
>>>     if (n < (int)len) break; <<<
        len = n + 1;
    }

As suggest into the Unix man page of the vsnprintf() example, The condition to exit the loop would be :

    if (n > -1 && n < size) break;