Method c_ptr

sql/sql_string.h:665–694

  }

  inline char *c_ptr()
  {
    if (unlikely(!Ptr))
      return (char*) "";
    /*
      Here we assume that any buffer used to initialize String has
      an end \0 or have at least an accessable character at end.
      This is to handle the case of String("Hello",5) and
      String("hello",5) efficiently.

      We have two options here. To test for !Alloced_length or !alloced.
      Using "Alloced_length" is slightly safer so that we do not read
      from potentially uninitialized memory (normally not dangerous but
      may give warnings in valgrind), but "alloced" is safer as there
      are less change to get memory loss from code that is using
      String((char*), length) or String.set((char*), length) and does
      not free things properly (and there is several places in the code
      where this happens and it is hard to find out if any of these will call
      c_ptr().
    */
    if (unlikely(!alloced && !Ptr[str_length]))
      return Ptr;
    if (str_length < Alloced_length)
    {
      Ptr[str_length]=0;
      return Ptr;
    }
    (void) realloc(str_length);               /* This will add end \0 */
    return Ptr;
  }
  /*
    One should use c_ptr() instead for most cases. This will be deleted soon,
    kept for compatibility.