Add `FT_LCD_FILTER_LEGACY1' enum value.

This does the same as `FT_LCD_FILTER_LEGACY'.

See

  https://bugs.freedesktop.org/show_bug.cgi?id=92981

for the reasoning.

* include/freetype/ftlcdfil.h (FT_LcdFilter): New value
`FT_LCD_FILTER_LEGACY1'.

* src/base/ftlcdfil.c (FT_Library_SetLcdFilter): Use it.

ChangeLog

@@ -1,3 +1,20 @@
+2015-11-20  Werner Lemberg  <wl@gnu.org>
+
+	Add `FT_LCD_FILTER_LEGACY1' enum value.
+
+	This does the same as `FT_LCD_FILTER_LEGACY'.
+
+	See
+
+	  https://bugs.freedesktop.org/show_bug.cgi?id=92981
+
+	for the reasoning.
+
+	* include/freetype/ftlcdfil.h (FT_LcdFilter): New value
+	`FT_LCD_FILTER_LEGACY1'.
+
+	* src/base/ftlcdfil.c (FT_Library_SetLcdFilter): Use it.
+
 2015-11-15  Werner Lemberg  <wl@gnu.org>
 
 	* src/autofit/afhints.c (af_get_segment_index): Fix it.

include/freetype/ftlcdfil.h

@@ -126,14 +126,23 @@ FT_BEGIN_HEADER
    *     This filter is only provided for comparison purposes, and might be
    *     disabled or stay unsupported in the future.
    *
+   *   FT_LCD_FILTER_LEGACY1 ::
+   *     For historical reasons, the FontConfig library returns a different
+   *     enumeration value for legacy LCD filtering.  To make code work that
+   *     (incorrectly) forwards FontConfig's enumeration value to
+   *     @FT_Library_SetLcdFilter without proper mapping, it is thus easiest
+   *     to have another enumeration value, which is completely equal to
+   *     `FT_LCD_FILTER_LEGACY'.
+   *
    * @since:
-   *   2.3.0
+   *   2.3.0 (`FT_LCD_FILTER_LEGACY1' since 2.6.2)
    */
   typedef enum  FT_LcdFilter_
   {
     FT_LCD_FILTER_NONE    = 0,
     FT_LCD_FILTER_DEFAULT = 1,
     FT_LCD_FILTER_LIGHT   = 2,
+    FT_LCD_FILTER_LEGACY1 = 3,
     FT_LCD_FILTER_LEGACY  = 16,
 
     FT_LCD_FILTER_MAX   /* do not remove */

src/base/ftlcdfil.c

@@ -354,6 +354,7 @@
 #ifdef USE_LEGACY
 
     case FT_LCD_FILTER_LEGACY:
+    case FT_LCD_FILTER_LEGACY1:
       library->lcd_filter_func = _ft_lcd_filter_legacy;
       library->lcd_extra       = 0;
       break;