+       dest is always aligned on common platforms                                                               
+       (if sizeof(PyASCIIObject) is divisible by SIZEOF_LONG).                                                  

Actually, that’s the part that is not true. On m68k, and perfectly
permitted by the C standard, even a 24-byte object has only a
guaranteed alignment of 2 bytes (or one, if it’s a char array)
in the normal case (contains integers and pointers, nothing special).

We patched out this bogus assumption from things like glib already ;)