Method extra_allocation

sql/sql_string.h:467–467

  bool is_alloced() const { return alloced; }
  inline uint32 alloced_length() const { return Alloced_length;}
  inline uint32 extra_allocation() const { return extra_alloc;}
  inline void extra_allocation(size_t len) { extra_alloc= (uint32)len; }
  inline void mark_as_const() { Alloced_length= 0;}