libc: strcpy and strncpy do not check if the strings overlap

[Lukáš Zaoral]

Hello,
the implementations of strcpy and strncpy should check, that the memory areas do overlap (like the implementation of memcpy does). At the moment, the following programs are mistakenly verified as correct. Thanks.

a) strcpy:

  #include <string.h>

  int main(void)
  {
      char str[] = "test";
      strcpy(str, str + 1);
  }

b) strncpy:

  #include <string.h>

  int main(void)
  {
      char str[] = "test";
      strncpy(str, str + 1, 2);
  }

[mornfall]

Fixed in next.