From f4e9a102d89f573de4b800bf785128483972a06e Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Tue, 25 Apr 1989 02:25:10 +0000
Subject: [PATCH] Change `xterm-read-chars': if called with non-false interval,
 and an event flag is set during that interval, return immediately.  If no
 characters have been received, return the amount of the interval which
 remains, so the primitive can be continued by reentering it with this number
 as its argument.

---
 v7/src/microcode/version.h |  4 ++--
 v7/src/microcode/x11term.c | 34 ++++++++++++++++++++--------------
 v8/src/microcode/version.h |  4 ++--
 3 files changed, 24 insertions(+), 18 deletions(-)

diff --git a/v7/src/microcode/version.h b/v7/src/microcode/version.h
index 782788eb8..7472ca278 100644
--- a/v7/src/microcode/version.h
+++ b/v7/src/microcode/version.h
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/Attic/version.h,v 10.74 1989/04/19 02:30:24 arthur Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/Attic/version.h,v 10.75 1989/04/25 02:25:10 cph Exp $
 
 Copyright (c) 1988, 1989 Massachusetts Institute of Technology
 
@@ -46,7 +46,7 @@ MIT in each case. */
 #define VERSION		10
 #endif
 #ifndef SUBVERSION
-#define SUBVERSION	74
+#define SUBVERSION	75
 #endif
 
 #ifndef UCODE_TABLES_FILENAME
diff --git a/v7/src/microcode/x11term.c b/v7/src/microcode/x11term.c
index 629c7c0ff..b628687d0 100644
--- a/v7/src/microcode/x11term.c
+++ b/v7/src/microcode/x11term.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/x11term.c,v 1.2 1989/04/20 04:33:52 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/x11term.c,v 1.3 1989/04/25 02:24:20 cph Exp $
 
 Copyright (c) 1989 Massachusetts Institute of Technology
 
@@ -987,26 +987,25 @@ DEFINE_PRIMITIVE ("XTERM-READ-CHARS", Prim_xterm_read_chars, 2, 2, 0)
   interval =
     (((ARG_REF (2)) == SHARP_F) ? (-1) : (arg_nonnegative_integer (2)));
   if (interval >= 0)
-    time_limit = ((OS_real_time_clock ()) + (interval));
+    time_limit = ((OS_real_time_clock ()) + interval);
   buffer_length = 4;
   buffer_index = 0;
   buffer = (xterm_malloc (buffer_length));
   scan_buffer = buffer;
   while (1)
     {
-      if (interval < 0)
-	{
-	  if (((XPending (display)) == 0) &&
-	      ((buffer != scan_buffer) || ((xt -> event_flags) != 0)))
-	    break;
-	}
-      else
+      if ((XPending (display)) == 0)
 	{
 	  if ((buffer != scan_buffer) ||
-	      ((OS_real_time_clock ()) >= time_limit))
+	      ((xt -> event_flags) != 0) ||
+	      (interval == 0))
 	    break;
-	  if ((XPending (display)) == 0)
-	    continue;
+	  if (interval > 0)
+	    {
+	      if ((OS_real_time_clock ()) >= time_limit)
+		break;
+	      continue;
+	    }
 	}
       XNextEvent (display, (& event));
       if ((event . type) != KeyPress)
@@ -1040,9 +1039,16 @@ DEFINE_PRIMITIVE ("XTERM-READ-CHARS", Prim_xterm_read_chars, 2, 2, 0)
 	(*scan_buffer++) = (*scan_copy++);
       buffer_index = (scan_buffer - buffer);
     }
-  if (buffer == scan_buffer)
+  /* If we got characters, return them */
+  if (buffer != scan_buffer)
+    PRIMITIVE_RETURN (memory_to_string (buffer_index, buffer));
+  /* If we're in a read with timeout, and we stopped before the
+     timeout was finished, return the amount remaining. */
+  if (interval > 0)
+    interval = (time_limit - (OS_real_time_clock ()));
+  if (interval <= 0)
     PRIMITIVE_RETURN (SHARP_F);
-  PRIMITIVE_RETURN (memory_to_string (buffer_index, buffer));
+  PRIMITIVE_RETURN (C_Integer_To_Scheme_Integer (interval));
 }
 
 static void
diff --git a/v8/src/microcode/version.h b/v8/src/microcode/version.h
index a478a90d8..c46a92606 100644
--- a/v8/src/microcode/version.h
+++ b/v8/src/microcode/version.h
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v8/src/microcode/version.h,v 10.74 1989/04/19 02:30:24 arthur Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v8/src/microcode/version.h,v 10.75 1989/04/25 02:25:10 cph Exp $
 
 Copyright (c) 1988, 1989 Massachusetts Institute of Technology
 
@@ -46,7 +46,7 @@ MIT in each case. */
 #define VERSION		10
 #endif
 #ifndef SUBVERSION
-#define SUBVERSION	74
+#define SUBVERSION	75
 #endif
 
 #ifndef UCODE_TABLES_FILENAME
-- 
2.25.1