Use empty_unibyte_string where applicable.

* keyboard.c (parse_tool_bar_item): Use empty_unibyte_string.
* lread.c (read1): Likewise.
* xsettings.c (syms_of_xsettings): Likewise.

src/ChangeLog

+2012-07-12  Dmitry Antipov  <dmantipov@yandex.ru>
+
+	Use empty_unibyte_string where applicable.
+	* keyboard.c (parse_tool_bar_item): Use empty_unibyte_string.
+	* lread.c (read1): Likewise.
+	* xsettings.c (syms_of_xsettings): Likewise.
+
 2012-07-12  Glenn Morris  <rgm@gnu.org>
 
 	* s/cygwin.h (G_SLICE_ALWAYS_MALLOC):

src/keyboard.c

@@ -8331,7 +8331,7 @@ parse_tool_bar_item (Lisp_Object key, Lisp_Object item)
       if (SCHARS (new_lbl) <= tool_bar_max_label_size)
         PROP (TOOL_BAR_ITEM_LABEL) = new_lbl;
       else
-        PROP (TOOL_BAR_ITEM_LABEL) = make_string ("", 0);
+        PROP (TOOL_BAR_ITEM_LABEL) = empty_unibyte_string;
       xfree (buf);
     }
 

src/lread.c

@@ -2670,13 +2670,13 @@ read1 (register Lisp_Object readcharfun, int *pch, int first_in_list)
 	      /* No symbol character follows, this is the empty
 		 symbol.  */
 	      UNREAD (c);
-	      return Fmake_symbol (build_string (""));
+	      return Fmake_symbol (empty_unibyte_string);
 	    }
 	  goto read_symbol;
 	}
       /* ## is the empty symbol.  */
       if (c == '#')
-	return Fintern (build_string (""), Qnil);
+	return Fintern (empty_unibyte_string, Qnil);
       /* Reader forms that can reuse previously read objects.  */
       if (c >= '0' && c <= '9')
 	{

src/xsettings.c

@@ -1035,7 +1035,7 @@ If this variable is nil, Emacs ignores system font changes.  */);
 
   DEFVAR_LISP ("xft-settings", Vxft_settings,
                doc: /* Font settings applied to Xft.  */);
-  Vxft_settings = make_string ("", 0);
+  Vxft_settings = empty_unibyte_string;
 
 #ifdef HAVE_XFT
   Fprovide (intern_c_string ("font-render-setting"), Qnil);