=== modified file 'src/xdisp.c'
--- src/xdisp.c	2014-08-01 13:10:07 +0000
+++ src/xdisp.c	2014-08-05 15:28:23 +0000
@@ -9713,7 +9713,7 @@
 	  && it->dpvec + it->current.dpvec_index != it->dpend);
 }

-DEFUN ("window-text-pixel-size", Fwindow_text_pixel_size, Swindow_text_pixel_size, 0, 6, 0,
+DEFUN ("window-text-pixel-size", Fwindow_text_pixel_size, Swindow_text_pixel_size, 0, 7, 0,
        doc: /* Return the size of the text of WINDOW's buffer in pixels.
 WINDOW must be a live window and defaults to the selected one.  The
 return value is a cons of the maximum pixel-width of any text line and
@@ -9746,9 +9746,13 @@
 include the height of the mode- or header-line of WINDOW in the return
 value.  If it is either the symbol `mode-line' or `header-line', include
 only the height of that line, if present, in the return value.  If t,
-include the height of both, if present, in the return value.  */)
+include the height of both, if present, in the return value.
+
+Optional argument BUFFER, if non-nil, means to work on another buffer
+than that displayed in WINDOW.  If BUFFER denotes a live buffer, use
+that buffer.  If BUFFER equals t, use the current buffer.  */)
   (Lisp_Object window, Lisp_Object from, Lisp_Object to, Lisp_Object x_limit, Lisp_Object y_limit,
-   Lisp_Object mode_and_header_line)
+   Lisp_Object mode_and_header_line, Lisp_Object buffer)
 {
   struct window *w = decode_live_window (window);
   Lisp_Object buf;
@@ -9760,14 +9764,25 @@
   void *itdata = NULL;
   int c, max_y = -1, x = 0, y = 0;

-  buf = w->contents;
-  CHECK_BUFFER (buf);
-  b = XBUFFER (buf);
-
-  if (b != current_buffer)
+  if (!EQ (buffer, Qt))
     {
-      old_buffer = current_buffer;
-      set_buffer_internal (b);
+      if (NILP (buffer))
+	{
+	  buf = w->contents;
+	  CHECK_BUFFER (buf);
+	  b = XBUFFER (buf);
+	}
+      else
+	{
+	  CHECK_BUFFER (buffer);
+	  b = XBUFFER (buffer);
+	}
+
+      if (b != current_buffer)
+	{
+	  old_buffer = current_buffer;
+	  set_buffer_internal (b);
+	}
     }

   if (NILP (from))
@@ -15814,6 +15829,17 @@
 	 left.  */
       whole = max (whole, w->hscroll + box_width);
       whole = max (whole, end - start);
+      if (it.bidi_p)
+	{
+	  Lisp_Object pdir;
+
+	  pdir = Fcurrent_bidi_paragraph_direction (Qnil);
+	  if (EQ (pdir, Qright_to_left))
+	    {
+	      end = whole - w->hscroll * FRAME_COLUMN_WIDTH (WINDOW_XFRAME (w));
+	      start = end - box_width;
+	    }
+	}

       if (old_buffer)
 	set_buffer_internal (old_buffer);