[sfnt] Adjust behaviour of PS font names for variation fonts.

* src/sfnt/sfdriver.c (sfnt_get_var_ps_name): Use a named instance's
PS name only if no variation is applied.

ChangeLog

@@ -1,3 +1,10 @@
+2017-10-07  Werner Lemberg  <wl@gnu.org>
+
+	[sfnt] Adjust behaviour of PS font names for variation fonts.
+
+	* src/sfnt/sfdriver.c (sfnt_get_var_ps_name): Use a named instance's
+	PS name only if no variation is applied.
+
 2017-10-07  Werner Lemberg  <wl@gnu.org>
 
 	[cff, truetype] Adjust behaviour of named instances.

include/freetype/freetype.h

@@ -3519,6 +3519,13 @@ FT_BEGIN_HEADER
   /*                                                                       */
   /*      http://wwwimages.adobe.com/content/dam/Adobe/en/devnet/font/pdfs/5902.AdobePSNameGeneration.html */
   /*                                                                       */
+  /*    [Since 2.8.2] Special PostScript names for named instances are     */
+  /*    only returned if the named instance is set with                    */
+  /*    @FT_Set_Named_Instance (and the font has corresponding entries in  */
+  /*    its `fvar' table).  If @FT_IS_VARIATION returns true, the          */
+  /*    algorithmically derived PostScript name is provided, not looking   */
+  /*    up special entries for named instances.                            */
+  /*                                                                       */
   FT_EXPORT( const char* )
   FT_Get_Postscript_Name( FT_Face  face );
 

src/sfnt/sfdriver.c

@@ -862,7 +862,8 @@
                        NULL,
                        &mm_var );
 
-    if ( FT_IS_NAMED_INSTANCE( FT_FACE( face ) ) )
+    if ( FT_IS_NAMED_INSTANCE( FT_FACE( face ) ) &&
+         !FT_IS_VARIATION( FT_FACE( face ) )     )
     {
       SFNT_Service  sfnt = (SFNT_Service)face->sfnt;