>From e828710d75d1271957375b8b132bef0c4e62a964 Mon Sep 17 00:00:00 2001
From: Alan Third <address@hidden>
Date: Thu, 4 Oct 2018 22:47:23 +0100
Subject: [PATCH] Fix NS redraw errors

* src/nsterm.m (ns_clip_to_rect, ns_reset_clipping): Always pop the
graphics state.
(ns_copy_bits): Remove function.
(ns_scroll_run):
(ns_shift_glyphs_for_insert): Remove references to ns_copy_bits and
mark changed areas for redraw.
---
 src/nsterm.m | 39 ++++++++++-----------------------------
 1 file changed, 10 insertions(+), 29 deletions(-)

diff --git a/src/nsterm.m b/src/nsterm.m
index d92d6c3244..e4958543eb 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -277,7 +277,6 @@ - (NSColor *)colorUsingDefaultColorSpace
 
 /* display update */
 static int ns_window_num = 0;
-static BOOL gsaved = NO;
 static BOOL ns_fake_keydown = NO;
 #ifdef NS_IMPL_COCOA
 static BOOL ns_menu_bar_is_hidden = NO;
@@ -1180,7 +1179,6 @@ static NSRect constrain_frame_rect(NSRect frameRect, bool isFullscreen)
             NSRectClipList (r, 2);
           else
             NSRectClip (*r);
-          gsaved = YES;
 
           return YES;
         }
@@ -1204,11 +1202,7 @@ static NSRect constrain_frame_rect(NSRect frameRect, bool isFullscreen)
 {
   NSTRACE_WHEN (NSTRACE_GROUP_FOCUS, "ns_reset_clipping");
 
-  if (gsaved)
-    {
-      [[NSGraphicsContext currentContext] restoreGraphicsState];
-      gsaved = NO;
-    }
+  [[NSGraphicsContext currentContext] restoreGraphicsState];
 }
 
 
@@ -2707,23 +2701,6 @@ so some key presses (TAB) are swallowed by the system. */
     }
 }
 
-static void
-ns_copy_bits (struct frame *f, NSRect src, NSRect dest)
-{
-  NSTRACE ("ns_copy_bits");
-
-  if (FRAME_NS_VIEW (f))
-    {
-      hide_bell();              // Ensure the bell image isn't scrolled.
-
-      /* FIXME: scrollRect:by: is deprecated in macOS 10.14.  There is
-         no obvious replacement so we may have to come up with our own.  */
-      [FRAME_NS_VIEW (f) scrollRect: src
-                                 by: NSMakeSize (dest.origin.x - src.origin.x,
-                                                 dest.origin.y - src.origin.y)];
-    }
-}
-
 static void
 ns_scroll_run (struct window *w, struct run *run)
 /* --------------------------------------------------------------------------
@@ -2773,10 +2750,12 @@ so some key presses (TAB) are swallowed by the system. */
   x_clear_cursor (w);
 
   {
-    NSRect srcRect = NSMakeRect (x, from_y, width, height);
+    /* We should do this by copying the contents of the NSView,
+       however x_clear_cursor, above, seems to leave detritus since we
+       changed to the mark-dirty/expose method, and simply redrawing
+       the whole thing seems to have no performance issues.  */
     NSRect dstRect = NSMakeRect (x, to_y, width, height);
-
-    ns_copy_bits (f, srcRect , dstRect);
+    [FRAME_NS_VIEW (f) setNeedsDisplayInRect:dstRect];
   }
 
   unblock_input ();
@@ -2830,12 +2809,14 @@ so some key presses (TAB) are swallowed by the system. */
     External (RIF): copy an area horizontally, don't worry about clearing src
    -------------------------------------------------------------------------- */
 {
-  NSRect srcRect = NSMakeRect (x, y, width, height);
+  /* This should be done by copying the contents of the screen,
+     however we can get away with just marking the destination as
+     needing redrawn.  */
   NSRect dstRect = NSMakeRect (x+shift_by, y, width, height);
 
   NSTRACE ("ns_shift_glyphs_for_insert");
 
-  ns_copy_bits (f, srcRect, dstRect);
+  [FRAME_NS_VIEW (f) setNeedsDisplayInRect:dstRect];
 }
 
 
-- 
2.18.0