add comments explaining why seval-handler is buggy

scheme/httpd/seval.scm

@@ -47,6 +47,7 @@
 
 
 (define (seval path req)
+  ;;bug: we make 200 response, no matter if the request contained a valid Content-length: header or not (see below)
     (make-response
      (status-code ok)
      #f
@@ -54,6 +55,9 @@
      "text/html"
      '()
      (make-reader-writer-body 
+      ;; this procedure's body is not evaluated until display-http-body is called from sent-http-response.
+      ;; this way the errors which are thrown by read-request-sexp for unvalid Content-length headers are syslogged 
+      ;; (and no body is written out at all), but we still have the 200 status-line.
       (lambda (iport oport options) 
 	(let ((sexp (read-request-sexp req iport)))
 	  (http-syslog (syslog-level debug) "read sexp: ~a" sexp)