Doh.  Don't use CPAL or COLR data if tables are missing.

Reported by Alexei.

* src/sfnt/ttcolr.c (tt_face_get_colr_layer): Return immediately if
`colr' is NULL.

* src/sfnt/ttcpal.c (tt_face_palette_set): Return immediately, if
`cpal' is NULL.
diff --git a/ChangeLog b/ChangeLog
index ce05ec5..af02921 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2018-06-19  Werner Lemberg  <wl@gnu.org>
+
+	Doh.  Don't use CPAL or COLR data if tables are missing.
+
+	Reported by Alexei.
+
+	* src/sfnt/ttcolr.c (tt_face_get_colr_layer): Return immediately if
+	`colr' is NULL.
+
+	* src/sfnt/ttcpal.c (tt_face_palette_set): Return immediately, if
+	`cpal' is NULL.
+
 2018-06-17  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	[base] Introduce `FT_New_Glyph'.
diff --git a/src/sfnt/ttcolr.c b/src/sfnt/ttcolr.c
index 4fc4300..b12ebe2 100644
--- a/src/sfnt/ttcolr.c
+++ b/src/sfnt/ttcolr.c
@@ -220,6 +220,9 @@
     FT_UInt          glyph_index;
 
 
+    if ( !colr )
+      return 0;
+
     if ( !iterator->p )
     {
       FT_ULong  offset;
diff --git a/src/sfnt/ttcpal.c b/src/sfnt/ttcpal.c
index 6c6b06d..fc78c67 100644
--- a/src/sfnt/ttcpal.c
+++ b/src/sfnt/ttcpal.c
@@ -258,7 +258,7 @@
     FT_ULong  record_offset;
 
 
-    if ( palette_index >= face->palette_data.num_palettes )
+    if ( !cpal || palette_index >= face->palette_data.num_palettes )
       return FT_THROW( Invalid_Argument );
 
     offset        = cpal->color_indices + 2 * palette_index;