[sfnt] Disable bitmap strikes if we don't have a bitmap data table.

* src/sfnt/ttsbit.c (tt_face_load_sbit): Check whether we have
a bitmap data table.

ChangeLog

@@ -1,3 +1,10 @@
+2016-10-01  Werner Lemberg  <wl@gnu.org>
+
+	[sfnt] Disable bitmap strikes if we don't have a bitmap data table.
+
+	* src/sfnt/ttsbit.c (tt_face_load_sbit): Check whether we have
+	a bitmap data table.
+
 2016-10-01  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	[smooth] Remove impossibility.

src/sfnt/ttsbit.c

@@ -190,12 +190,14 @@
       break;
 
     default:
+      /* we ignore unknown table formats */
       error = FT_THROW( Unknown_File_Format );
       break;
     }
 
     if ( !error )
-      FT_TRACE3(( "sbit_num_strikes: %u\n", face->sbit_num_strikes ));
+      FT_TRACE3(( "tt_face_load_sbit_strikes: found %u strikes\n",
+                  face->sbit_num_strikes ));
 
     face->ebdt_start = 0;
     face->ebdt_size  = 0;
@@ -218,6 +220,15 @@
       }
     }
 
+    if ( !face->ebdt_size )
+    {
+      FT_TRACE2(( "tt_face_load_sbit_strikes:"
+                  " no embedded bitmap data table found;\n"
+                  "                          "
+                  " resetting number of strikes to zero\n" ));
+      face->sbit_num_strikes = 0;
+    }
+
     return FT_Err_Ok;
 
   Exit: