added CFF1 Expert Encoding subset test & bug fixes

src/hb-ot-cff1-table.hh

@@ -1121,7 +1121,13 @@ struct cff1
     
       const OT::cff1 *cff = this->blob->as<OT::cff1> ();
       encoding = &Null(Encoding);
-      charset = &StructAtOffsetOrNull<Charset> (cff, topDict.CharsetOffset);
+      if (is_predef_charset ())
+        charset = &Null(Charset);
+      else
+      {
+        charset = &StructAtOffsetOrNull<Charset> (cff, topDict.CharsetOffset);
+        if (unlikely ((charset == &Null (Charset)) || !charset->sanitize (&sc))) { fini (); return; }
+      }
       if (is_CID ())
       {
         if (unlikely (charset == &Null(Charset))) { fini (); return; }

src/hb-subset-cff1.cc

@@ -615,12 +615,18 @@ struct cff_subset_plan {
     final_size += offsets.globalSubrsInfo.size;
 
     /* Encoding */
-    offsets.encodingOffset = final_size;
+    if (!subset_encoding && acc.is_predef_charset ())
+      offsets.encodingOffset = acc.topDict.EncodingOffset;
+    else
+      offsets.encodingOffset = final_size;
     if (subset_encoding)
       final_size += plan_subset_encoding (acc, plan);
 
     /* Charset */
-    offsets.charsetInfo.offset = final_size;
+    if (!subset_charset && acc.is_predef_charset ())
+      offsets.charsetInfo.offset = acc.topDict.CharsetOffset;
+    else
+      offsets.charsetInfo.offset = final_size;
     final_size += offsets.charsetInfo.size;
 
     /* FDSelect */

test/api/test-subset-cff1.c

@@ -111,6 +111,26 @@ test_subset_cff1_j (void)
   hb_face_destroy (face_41_4c2e);
 }
 
+static void
+test_subset_cff1_expert (void)
+{
+  hb_face_t *face = hb_subset_test_open_font ("fonts/cff1_expert.otf");
+  hb_face_t *face_subset = hb_subset_test_open_font ("fonts/cff1_expert.2D,F6E9,FB00.otf");
+
+  hb_set_t *codepoints = hb_set_create ();
+  hb_set_add (codepoints, 0x2D);
+  hb_set_add (codepoints, 0xF6E9);
+  hb_set_add (codepoints, 0xFB00);
+  hb_face_t *face_test = hb_subset_test_create_subset (face, hb_subset_test_create_input (codepoints));
+  hb_set_destroy (codepoints);
+
+  hb_subset_test_check (face_subset, face_test, HB_TAG ('C','F','F',' '));
+
+  hb_face_destroy (face_test);
+  hb_face_destroy (face_subset);
+  hb_face_destroy (face);
+}
+
 int
 main (int argc, char **argv)
 {
@@ -120,6 +140,7 @@ main (int argc, char **argv)
   hb_test_add (test_subset_cff1);
   hb_test_add (test_subset_cff1_strip_hints);
   hb_test_add (test_subset_cff1_j);
+  hb_test_add (test_subset_cff1_expert);
 
   return hb_test_run ();
 }