+ ;;
+ ;; RLT comments in CMUCL about changing the following line to
+ ;; store at -1 instead of 0:
+ ;; This used to write to the word after the last allocated word. I
+ ;; (RLT) made it write to the last allocated word, which is where
+ ;; the zero-byte of the string is. Look at the deftransform for
+ ;; make-array in array-tran.lisp. For strings we always allocate
+ ;; enough space to hold the zero-byte.
+ ;; Which is most certainly motivated by the fact that this store (if
+ ;; performed on gencgc) overwrites the first word of the following
+ ;; page -- destroying the first object of an unrelated allocation region!
+ ;;
+ ;; But the CMUCL fix breaks :ELEMENT-TYPE NIL strings, so we'd need a
+ ;; branch to figure out whether to do it. Until and unless someone
+ ;; demonstrates that gencgc actually gives us uncommitted memory, I'm
+ ;; just not doing it at all: -- DFL
+ #!-gencgc