From: Joe Marshall <jmarshall@alum.mit.edu>
Date: Sat, 16 Jan 2016 23:53:58 +0000 (-0800)
Subject: Don't blow out the stack in STREAM->LIST.
X-Git-Tag: mit-scheme-pucked-9.2.12~373^2~8
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=2cc6c470d252fd1f30b1f3697615c667d6d6b8f6;p=mit-scheme.git

Don't blow out the stack in STREAM->LIST.
---

diff --git a/src/runtime/stream.scm b/src/runtime/stream.scm
index 6c49ebc35..e0a0e306e 100644
--- a/src/runtime/stream.scm
+++ b/src/runtime/stream.scm
@@ -265,13 +265,11 @@ USA.
 	'())))
 
 (define (stream->list stream)
-  (if (stream-pair? stream)
-      (cons (car stream)
-	    (stream->list (force (cdr stream))))
-      (begin
-	(if (not (null? stream))
-	    (error:illegal-stream-element stream 'STREAM->LIST 0))
-	'())))
+  (let loop ((s stream)
+	     (elements '()))
+    (cond ((stream-pair? tail) (loop (tail s) (cons (head s) elements)))
+	  ((null? s) (reverse elements))
+	  (else (error:illegal-stream-element stream 'STREAM->LIST 0)))))
 
 (define prime-numbers-stream)