This patch eliminates a line length limit in pop3resp.  It changes
pop3resp to use Brdstr rather than Brdline.  The patched pop3resp
still takes care of memory management for its callers: A line is freed
when the next line is read.

The limit causes upas/fs to blow up with "unexpected eof" and
"unexpected end of conversation" when unreasonable messages exist on a
POP server.

Notes:
Mon Jan 31 20:26:12 EST 2005 swasey
    I had forgotten that free(0) is a noop.  I suggest you replace
    "if(l){ free(l); l = s; }" in the patch with "free(l); l = s;".

Wed Feb 2 10:33:17 EST 2005 rsc
    This assumes that there is only one POP3 mail box open.
    

Wed Feb 2 10:36:04 EST 2005 rsc
    Also, you didn't change Blinelen to strlen, suggesting
    that you've not actually tried this on servers with
    such enormous lines.  Do they actually exist?
    


Reference: /n/sources/patch/applied/pop3resp
Date: Wed Feb  2 16:37:38 CET 2005
Reviewed-by: rsc

--- /sys/src/cmd/upas/fs/pop3.c	Wed Feb  2 16:37:38 2005
+++ /sys/src/cmd/upas/fs/pop3.c	Wed Feb  2 16:37:38 2005
@@ -80,9 +80,10 @@
 {
 	char *s;
 	char *p;
+	static char *l = nil;
 
 	alarm(60*1000);
-	if((s = Brdline(&pop->bin, '\n')) == nil){
+	if((s = Brdstr(&pop->bin, '\n', 0)) == nil){
 		close(pop->fd);
 		pop->fd = -1;
 		alarm(0);
@@ -90,6 +91,10 @@
 	}
 	alarm(0);
 
+	if(l){
+		free(l);
+		l = s;
+	}
 	p = s+Blinelen(&pop->bin)-1;
 	while(p >= s && (*p == '\r' || *p == '\n'))
 		*p-- = '\0';