really remove that POST-bindings-cache bug

scheme/httpd/surflets/bindings.scm

@@ -5,7 +5,7 @@
 ;; a later GET-BINDINGS call on the same POST request. The requests
 ;; are referenced by a weak pointer. Thread-safe as all threads use
 ;; the same lock.
-(define *POST-bindings-cache* '(#f))
+(define *POST-bindings-cache* '())
 (define *cache-lock* (make-lock))
 
 (define (get-bindings surflet-request)
@@ -54,20 +54,29 @@
 (define (cached-bindings surflet-request)
   (obtain-lock *cache-lock*)
   (let ((result 
-	 (let loop ((cache *POST-bindings-cache*))
-	   (let ((tail (cdr cache)))
-	     (if (null? tail)	; cache has at least one element
+	 (let loop ((predecessor #f)
+		    (cache *POST-bindings-cache*))
+	     (if (null? cache)
 		 #f			; no such request cached
-		 (let* ((head (car tail))
+		 (let* ((head (car cache))
 			(s-req (weak-pointer-ref (car head))))
 		   (if s-req
 		       (if (eq? s-req surflet-request)
 			   (cdr head)	; request is cached
-			   (loop (cdr cache))) ; request isn't cached
+			   (loop (if predecessor
+				     (cdr predecessor)
+				     cache)
+				 (cdr cache))) ; request isn't cached
 		       (begin     ;; request object is gone ==> remove
-			 ;; it from list
-			 (set-cdr! cache (cdr tail))
-			 (loop cache)))))))))
+				  ;; it from list
+			 (if predecessor
+			     (set-cdr! predecessor (cdr cache))
+			     (set! *POST-bindings-cache* (cdr cache)))
+			 (loop predecessor
+			       (cdr predecessor)))))))))
+    (format (current-error-port)
+	    "POST-bindings-cache: ~S\n"
+	    *POST-bindings-cache*)
     (release-lock *cache-lock*)
     result))