Index: tcp.scm
===================================================================
--- tcp.scm	(revision 13272)
+++ tcp.scm	(working copy)
@@ -414,28 +414,33 @@
 			      m
 			      (loop n m start) ) ) ) ) )
 	       (lambda (p limit)	; read-line
-		 (let loop ((str #f))
+		 (let loop ((str #f)
+			    (limit (or limit (##sys#fudge 21))))
 		   (cond ((fx< bufindex buflen)
 			  (##sys#scan-buffer-line
 			   buf 
-			   buflen
+			   (fxmin buflen limit)
 			   bufindex
 			   (lambda (pos2 next)
-			     (let ((dest (##sys#make-string (fx- pos2 bufindex))))
+			     (let* ((len (fx- pos2 bufindex))
+				    (dest (##sys#make-string len)))
 			       (##core#inline "C_substring_copy" buf dest bufindex pos2 0)
 			       (set! bufindex next)
-			       (cond ((eq? pos2 next) ; no line-terminator encountered
+			       (cond ((eq? pos2 limit) ; no line-terminator, hit limit
+				      (if str (##sys#string-append str dest) dest))
+				     ((eq? pos2 next)  ; no line-terminator, hit buflen
 				      (read-input)
 				      (if (fx>= bufindex buflen)
 					  (or str "")
-					  (loop (if str (##sys#string-append str dest) dest)) ) )
+					  (loop (if str (##sys#string-append str dest) dest)
+						(fx- limit len)) ) )
 				     (else 
 				      (##sys#setislot p 4 (fx+ (##sys#slot p 4) 1))
 				      (if str (##sys#string-append str dest) dest)) ) ) ) ) )
 			 (else
 			  (read-input)
 			  (if (fx< bufindex buflen)
-			      (loop str)
+			      (loop str limit)
 			      #!eof) ) ) ) ) ) )
 	     (output
 	      (lambda (s)