str - reserve fix(BUG: crash when len arg was 0)

    - reserve_virtual changed so it will not return ptr
dynarray - reserve_virtual changed so it will not return ptr

dynarray.h

@@ -1189,14 +1189,12 @@ class dynarray
  ///Reserve address space for \a nitems of elements in virtual memory
  /** @param nitems number of items to reserve
  @return pointer to the first item of the array */
- T* reserve_virtual(uints nitems)
+ void reserve_virtual(uints nitems)
  {
  discard();
 
  _ptr = A::template reserve_virtual<T>(nitems);
  _set_count(0);
-
- return _ptr;
  }
 
  ///Reserve stack memory for \a nitems of elements using _alloca

str.h

@@ -2049,20 +2049,16 @@ class charstr
  /// @param m [optional] memory space to use
  char* reserve(uints len, mspace m = 0) {
  bool clear = _tstr.ptr() == nullptr;
- char* p = _tstr.reserve(len, true, m);
+ char* p = _tstr.reserve(len > 0 ? len : 1, true, m);
  if (clear)
  *p = 0;
  return p;
  }
 
  ///Reserve virtual memory for string buffer
  /// @param len min size for string to reserve (incl. term zero)
- char* reserve_virtual(uints len) {
- bool clear = _tstr.ptr() == nullptr;
- char* p = _tstr.reserve_virtual(len);
- if (clear)
- *p = 0;
- return p;
+ void reserve_virtual(uints len) {
+ _tstr.reserve_virtual(len);
  }
 
  ///Reserve stack memory for string buffer