[cff] fix incremental interface with new cff code.

* src/cff/cf2ft.c (cf2_getSeacComponent): When using the incremental
interface to retrieve glyph data for a SEAC, it be left to the
incremental interface callback to apply the encoding to raw
character index (as it was in the previous code).

ChangeLog

@@ -1,3 +1,12 @@
+2015-05-12  Chris Liddell  <chris.liddell@artifex.com>
+
+	[cff] fix incremental interface with new cff code.
+
+	* src/cff/cf2ft.c (cf2_getSeacComponent): When using the incremental
+	interface to retrieve glyph data for a SEAC, it be left to the
+	incremental interface callback to apply the encoding to raw
+	character index (as it was in the previous code).
+
 2015-04-29  Alexei Podtelezhnikov <apodtele@gmail.com>
 
 	[autofit] Speed up IUP.

src/cff/cf2ft.c

@@ -582,9 +582,18 @@
 
     FT_ZERO( buf );
 
-    gid = cff_lookup_glyph_by_stdcharcode( decoder->cff, code );
-    if ( gid < 0 )
-      return FT_THROW( Invalid_Glyph_Format );
+#ifdef FT_CONFIG_OPTION_INCREMENTAL
+    /* Incremental fonts don't necessarily have valid charsets.        */
+    /* They use the character code, not the glyph index, in this case. */
+    if ( decoder->builder.face->root.internal->incremental_interface )
+      gid = code;
+    else
+#endif /* FT_CONFIG_OPTION_INCREMENTAL */
+    {
+      gid = cff_lookup_glyph_by_stdcharcode( decoder->cff, code );
+      if ( gid < 0 )
+        return FT_THROW( Invalid_Glyph_Format );
+    }
 
     error = cff_get_glyph_data( decoder->builder.face,
                                 (CF2_UInt)gid,