Index: buffer.c
===================================================================
RCS file: /sources/emacs/emacs/src/buffer.c,v
retrieving revision 1.575
diff -r1.575 buffer.c
2184a2185,2189
> #ifdef REL_ALLOC
> extern void r_alloc_prepare_to_swap_pointers P_ ((POINTER_TYPE **,
> 						  POINTER_TYPE **));
> #endif
> 
2222a2228,2232
> #ifdef REL_ALLOC
>   r_alloc_prepare_to_swap_pointers (&current_buffer->own_text.beg,
> 				    &other_buffer->own_text.beg);
> #endif
> 
Index: ralloc.c
===================================================================
RCS file: /sources/emacs/emacs/src/ralloc.c,v
retrieving revision 1.69
diff -r1.69 ralloc.c
1225a1226,1248
> /* Swap relocatable data between two pointers.
>    This is used by buffer_swap_text.  Since buffer_swap_text swaps the
>    whole text structure in one go, this function has been written to only
>    update the internal pointers back to the variables, ready for when the
>    swap is actually done.  It must be called before the pointers are
>    swapped so that the state is consistent when find_bloc is called.  */
> void
> r_alloc_prepare_to_swap_pointers (p1, p2)
>      POINTER *p1, *p2;
> {
>   bloc_ptr bloc1, bloc2;
>   bloc1 = find_bloc (p1);
>   bloc2 = find_bloc (p2);
>   if (bloc1 == NIL_BLOC || bloc2 == NIL_BLOC)
>     abort ();
> 
>   /* Swap internal pointers back to the variables.  */
>   bloc1->variable = p2;
>   bloc2->variable = p1;
> 
>   /* It would be cleaner to do the actual swap here too, but it would
>      complicate buffer_swap_text.  */
> }