* open-logfile returns null-output-port if logfile cannot be opened for writing

* No output to stderr anymore. Output now goes to syslog. If syslogging
  is disabled, bad luck.

httpd-core.scm

@@ -39,9 +39,17 @@
 (define server/version  "Scheme-Underground/1.0")
 (define server/protocol "HTTP/1.0")
 
-; default: no logging
-; initialized by init-http-log!
+;; default: no logging
+;; initialized by init-http-log!
+
+;; CLF-logging
+;; if enabled, it will look like this:
+;;      (lambda req reply-code)
 (define http-log (lambda a #f))      ; makes logging in CLF
+
+;; syslogging
+;; if enabled, it will look like this:
+;; 	      (lambda (level fmt . args)
 (define http-syslog (lambda a #f))   ; makes syslog
 (define *http-syslog?* #f)           ; trigger used to avoid
                                      ;  unnecessary computations
@@ -52,8 +60,10 @@
   (set! *http-log-port* port))
 
 (define (init-http-log! options)
-  (init-http-port-log! (httpd-options-logfile options))
-  (init-http-syslog! (httpd-options-syslog? options)))
+  ;; syslog has to be initialized befor CLF-logging
+  ;; because it may generate syslog-messages
+  (init-http-syslog! (httpd-options-syslog? options))
+  (init-http-port-log! (httpd-options-logfile options)))
 
 (define (init-http-port-log! logfile)
   (let ((logport 
@@ -64,13 +74,13 @@
 	   logfile)
 	  ((eq? logfile #f)             ; no logging demanded
 	   #f)
-	; unexpected value of logfile; we'll use (current-error-port) instead
+	; unexpected value of logfile; 
 	  (else
-	   (format (current-error-port)
-		   "[httpd] Warning: Logfile was not specified correctly (given: ~S).~%
-                 Logging now to stderr.\n"
+	   (http-syslog 
+	    (syslog-level warning)
+	    "[httpd] Warning: Logfile was not specified correctly (given: ~S).~% No CLF logging."
 	    logfile)
-	   (current-error-port)))))
+	   (make-null-output-port)))))
 
     (if logfile                         ; if logging was specified, set up the logger
 	(let ((http-log-lock (make-lock)))
@@ -130,7 +140,7 @@
 (define (open-logfile logfile)	      
   (with-errno-handler*
    (lambda (errno packet)
-     (format (current-error-port) 
+     (http-syslog (syslog-level warning)
 		  "[httpd] Warning: An error occured while opening ~S for writing (~A).~%Send signal USR1 when the problem is fixed.~%"
 	     logfile
 	     (car packet))
@@ -608,7 +618,6 @@
 	     (if message (format out "<P>~%~a~%" message)))))
 
       ((= reply-code http-reply/internal-error)
-       (format (current-error-port) "ERROR: ~A~%" message)
        (http-syslog (syslog-level error) "internal-error: ~A" message)
        (if html-ok? 
 	   (begin