terminal.c's from_backend() no longer calls term_out(), because

term_out() can in turn call ldisc_send() which calls back to
from_backend() when local echo is enabled. This was giving rise to
crazy re-entrancy stuff and stack overflows. Instead from_backend()
deposits its data in a bufchain which term_out() empties the next
time it's called.

[originally from svn r1276]

scp.c

@@ -375,8 +375,6 @@ int from_backend(int is_stderr, char *data, int datalen)
 	return 0;
     }
 
-    inbuf_head = 0;
-
     /*
      * If this is before the real session begins, just return.
      */