bug in prompting loops

[hkt@zkm.de (Rick Taube)]

there is a stream bug in both the DOS and the NeXTStep versions of  
CLISP that causes output in a PROMPT/READ loop to get multiply  
printed after some number of correct occurences. On the NeXT the bug  
starts after 6 times through the loop, (after 12 on my DOS machine).  
Once the bug starts, with a bogus line getting printed) the prompt  
appears to gets doubled, then tripled, etc.  The bug is very easy to  
tickle, just eval this loop and type 1 as the answer. It may take a  
few time, but you should notice that the prompt starts going haywire  
fairly soon: 



> (loop (format t "type value:") (read))
type value:1
type value:1
type value:1
type value:1
type value:1
type value:1
type value:
1
type value:
type value:1
type value:
type value:type value:1
type value:
type value:type value:type value:1
type value:
type value:type value:type value:type value:1
type value:
type value:type value:type value:type value:type value:1
type value:
type value:type value:type value:type value:type value:type value:1
type value:
type value:type value:type value:type value:type value:type  
value:type value: