Re: Bidi reordering engine upgraded

[Eli Zaretskii <eliz@gnu.org>]

> From: Jan Djärv <jan.h.d@swipnet.se>
> Date: Fri, 17 Oct 2014 19:45:34 +0200
> Cc: Dmitry Antipov <dmantipov@yandex.ru>,
>  emacs-devel@gnu.org
> 
> > === modified file 'src/xdisp.c'
> > --- src/xdisp.c	2014-10-14 18:10:37 +0000
> > +++ src/xdisp.c	2014-10-16 07:16:49 +0000
> > @@ -2303,9 +2303,6 @@ get_phys_cursor_geometry (struct window 
> >      rectangle as wide as the glyph, but use a canonical character
> >      width instead.  */
> >   wd = glyph->pixel_width - 1;
> > -#if defined (HAVE_NTGUI) || defined (HAVE_NS)
> > -  wd++; /* Why? */
> > -#endif
> > 
> >   x = w->phys_cursor.x;
> >   if (x < 0)
> > 
> > 
> > I never understood why we subtract 1 pixel from the cursor glyph's
> > pixel_width, anyway, and w32 and ns countermanded that, as you see.
> > Maybe we should also limit 'wd' from below, so it is at least 1.
> > 
> > Jan, can you comment on these issues and on the proposed patch,
> > please?
> 
> As you figured out, XDrawRectangle with width 0 and non-zero height draws a 1-pixel width line.

Thanks.  Since this appears to be specific to X, I propose the
change below for the trunk.  Does it look reasonable?

The only other question is whether we want the hollow cursor on X to
disappear when the underlying glyph is displayed as a thin space of 1
pixel.  It doesn't disappear on w32 (and possibly also on NS, although
I cannot test that).  Opinions, anyone?

=== modified file 'src/xdisp.c'
--- src/xdisp.c	2014-10-14 18:10:37 +0000
+++ src/xdisp.c	2014-10-17 18:39:20 +0000
@@ -2302,10 +2302,7 @@ get_phys_cursor_geometry (struct window 
      glyph, and `x-stretch-block-cursor' is nil, don't draw a
      rectangle as wide as the glyph, but use a canonical character
      width instead.  */
-  wd = glyph->pixel_width - 1;
-#if defined (HAVE_NTGUI) || defined (HAVE_NS)
-  wd++; /* Why? */
-#endif
+  wd = glyph->pixel_width;
 
   x = w->phys_cursor.x;
   if (x < 0)

=== modified file 'src/xterm.c'
--- src/xterm.c	2014-10-17 16:14:37 +0000
+++ src/xterm.c	2014-10-17 18:42:08 +0000
@@ -7965,7 +7965,7 @@ x_draw_hollow_cursor (struct window *w, 
 
   /* Compute frame-relative coordinates for phys cursor.  */
   get_phys_cursor_geometry (w, row, cursor_glyph, &x, &y, &h);
-  wd = w->phys_cursor_width;
+  wd = w->phys_cursor_width - 1;
 
   /* The foreground of cursor_gc is typically the same as the normal
      background color, which can cause the cursor box to be invisible.  */
@@ -7981,9 +7981,9 @@ x_draw_hollow_cursor (struct window *w, 
      glyph, unless the cursor box is as wide as the glyph or wider
      (the latter happens when x-stretch-cursor is non-nil).  */
   if ((cursor_glyph->resolved_level & 1) != 0
-      && cursor_glyph->pixel_width > w->phys_cursor_width)
+      && cursor_glyph->pixel_width > wd)
     {
-      x += cursor_glyph->pixel_width - w->phys_cursor_width;
+      x += cursor_glyph->pixel_width - wd;
       if (wd > 0)
 	wd -= 1;
     }
@@ -8086,12 +8086,12 @@ x_draw_bar_cursor (struct window *w, str
 				    &dummy_y, &dummy_h);
 
 	  if ((cursor_glyph->resolved_level & 1) != 0
-	      && cursor_glyph->pixel_width > w->phys_cursor_width)
-	    x += cursor_glyph->pixel_width - w->phys_cursor_width;
+	      && cursor_glyph->pixel_width > w->phys_cursor_width - 1)
+	    x += cursor_glyph->pixel_width - w->phys_cursor_width - 1;
 	  XFillRectangle (dpy, window, gc, x,
 			  WINDOW_TO_FRAME_PIXEL_Y (w, w->phys_cursor.y +
 						   row->height - width),
-			  w->phys_cursor_width, width);
+			  w->phys_cursor_width - 1, width);
 	}
 
       XSetClipMask (dpy, gc, None);