diff --git a/lisp/emacs-lisp/byte-run.el b/lisp/emacs-lisp/byte-run.el
index c6ad209cd8e..abfcdb347a3 100644
--- a/lisp/emacs-lisp/byte-run.el
+++ b/lisp/emacs-lisp/byte-run.el
@@ -285,7 +285,7 @@ The return value is undefined.
           def))))
 
 
-;; Redefined in byte-optimize.el.
+;; Redefined in byte-opt.el.
 ;; This is not documented--it's not clear that we should promote it.
 (fset 'inline 'progn)
 
diff --git a/lisp/mh-e/mh-mime.el b/lisp/mh-e/mh-mime.el
index 9d1edf0fc47..69c57e0afdc 100644
--- a/lisp/mh-e/mh-mime.el
+++ b/lisp/mh-e/mh-mime.el
@@ -659,6 +659,7 @@ buttons for alternative parts that are usually suppressed."
          (attachmentp (equal (car (mm-handle-disposition handle))
                              "attachment"))
          (inlinep (and (equal (car (mm-handle-disposition handle)) "inline")
+                       (mm-automatic-display-p handle)
                        (mm-inlinable-p handle)
                        (mm-inlined-p handle)))
          (displayp (or inlinep                   ; show if inline OR
@@ -669,6 +670,7 @@ buttons for alternative parts that are usually suppressed."
                                 (and (not (equal
                                            (mm-handle-media-supertype handle)
                                            "image"))
+                                     (mm-automatic-display-p handle)
                                      (mm-inlinable-p handle)
                                      (mm-inlined-p handle)))))))
     (save-restriction
diff --git a/src/w32term.c b/src/w32term.c
index e62d49dd947..7a3b2cc631f 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -660,21 +660,25 @@ w32_draw_window_divider (struct window *w, int x0, int x1, int y0, int y1)
 			      ? face_last->foreground
 			      : FRAME_FOREGROUND_PIXEL (f));
 
-  if (y1 - y0 > x1 - x0 && x1 - x0 > 2)
-    /* Vertical.  */
+  if ((y1 - y0 > x1 - x0) && (x1 - x0 >= 3))
+    /* A vertical divider, at least three pixels wide: Draw first and
+       last pixels differently.  */
     {
       w32_fill_area_abs (f, hdc, color_first, x0, y0, x0 + 1, y1);
       w32_fill_area_abs (f, hdc, color, x0 + 1, y0, x1 - 1, y1);
       w32_fill_area_abs (f, hdc, color_last, x1 - 1, y0, x1, y1);
     }
-  else if (x1 - x0 > y1 - y0 && y1 - y0 > 3)
-    /* Horizontal.  */
+  else if ((x1 - x0 > y1 - y0) && (y1 - y0 >= 3))
+    /* A horizontal divider, at least three pixels high: Draw first and
+       last pixels differently.  */
     {
       w32_fill_area_abs (f, hdc, color_first, x0, y0, x1, y0 + 1);
       w32_fill_area_abs (f, hdc, color, x0, y0 + 1, x1, y1 - 1);
       w32_fill_area_abs (f, hdc, color_last, x0, y1 - 1, x1, y1);
     }
   else
+    /* In any other case do not draw the first and last pixels
+       differently.  */
     w32_fill_area_abs (f, hdc, color, x0, y0, x1, y1);
 
   release_frame_dc (f, hdc);
diff --git a/src/xterm.c b/src/xterm.c
index 28abfaecde9..1deb7b46013 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -1104,8 +1104,9 @@ x_draw_window_divider (struct window *w, int x0, int x1, int y0, int y1)
 			      : FRAME_FOREGROUND_PIXEL (f));
   Display *display = FRAME_X_DISPLAY (f);
 
-  if (y1 - y0 > x1 - x0 && x1 - x0 > 2)
-    /* Vertical.  */
+  if ((y1 - y0 > x1 - x0) && (x1 - x0 >= 3))
+    /* A vertical divider, at least three pixels wide: Draw first and
+       last pixels differently.  */
     {
       XSetForeground (display, f->output_data.x->normal_gc, color_first);
       x_fill_rectangle (f, f->output_data.x->normal_gc,
@@ -1117,8 +1118,9 @@ x_draw_window_divider (struct window *w, int x0, int x1, int y0, int y1)
       x_fill_rectangle (f, f->output_data.x->normal_gc,
 			x1 - 1, y0, 1, y1 - y0);
     }
-  else if (x1 - x0 > y1 - y0 && y1 - y0 > 3)
-    /* Horizontal.  */
+  else if ((x1 - x0 > y1 - y0) && (y1 - y0 >= 3))
+    /* A horizontal divider, at least three pixels high: Draw first and
+       last pixels differently.  */
     {
       XSetForeground (display, f->output_data.x->normal_gc, color_first);
       x_fill_rectangle (f, f->output_data.x->normal_gc,
@@ -1132,6 +1134,8 @@ x_draw_window_divider (struct window *w, int x0, int x1, int y0, int y1)
     }
   else
     {
+    /* In any other case do not draw the first and last pixels
+       differently.  */
       XSetForeground (display, f->output_data.x->normal_gc, color);
       x_fill_rectangle (f, f->output_data.x->normal_gc,
 			x0, y0, x1 - x0, y1 - y0);