[repack] fix incorrect extension object bounds.

src/graph/graph.hh

diff --git a/src/graph/graph.hh b/src/graph/graph.hh
index 8afa570..c9aaec1 100644
--- a/src/graph/graph.hh
+++ b/src/graph/graph.hh
@@ -310,41 +310,6 @@
     }
   }
 
-
-  /*
-  void promote_extension_lookups (const hb_set_t& subtable_indices)
-  {
-    const OT::GSUBGPOS* gstar = (OT::GSUBGPOS*) root ().obj.head;
-
-    unsigned lookup_list_idx = index_for_offset (root_idx (), &(gstar->lookupList));
-    const OT::LookupList<SmallTypes>* lookupList =
-        (OT::LookupList<SmallTypes>*) object (lookup_list_idx).head;
-
-
-    for (unsigned i = 0; i < lookupList->len; i++)
-    {
-      unsigned lookup_idx = index_for_offset (lookup_list_idx, &(lookupList->arrayZ[i]));
-      const OT::Lookup* lookup = (OT::Lookup*) object (lookup_idx).head;
-
-      // TODO(grieger): use the correct type for GSUB vs GPOS
-      if (lookup->get_type () == 9) continue; // skip extensions
-
-      for (unsigned j = 0; j < lookup->subTable.len; j++)
-      {
-        unsigned subtable_idx = index_for_offset (lookup_idx, &(lookup->subTable.arrayZ[j]));
-        if (subtable_indices.has (subtable_idx))
-          promote_to_extension (lookup_idx);
-      }
-    }
-  }
-
-  void promote_to_extension (unsigned lookup_idx)
-  {
-    DEBUG_MSG (SUBSET_REPACK, nullptr, "Promoting %d to extension lookup.", lookup_idx);
-    // TODO(garretrieger): implement me.
-  }
-  */
-
   unsigned index_for_offset(unsigned node_idx, const void* offset) const
   {
     const auto& node = object (node_idx);
@@ -642,7 +607,6 @@
   {
     positions_invalid = true;
     distance_invalid = true;
-    parents_invalid = true; // TODO: remove
 
     auto* clone = vertices_.push ();
     if (vertices_.in_error ()) {

src/graph/gsubgpos-graph.hh

diff --git a/src/graph/gsubgpos-graph.hh b/src/graph/gsubgpos-graph.hh
index 5a3321b..3a3b4c3 100644
--- a/src/graph/gsubgpos-graph.hh
+++ b/src/graph/gsubgpos-graph.hh
@@ -104,7 +104,7 @@
     unsigned type = lookupType;
     unsigned extension_size = OT::ExtensionFormat1<OT::Layout::GSUB_impl::ExtensionSubst>::static_size;
     unsigned start = buffer.length;
-    unsigned end = start + extension_size - 1;
+    unsigned end = start + extension_size;
     if (!buffer.resize (buffer.length + extension_size))
       // TODO: resizing potentially invalidates existing head/tail pointers.
       return false;
@@ -115,7 +115,11 @@
     extension->extensionLookupType = type;
     extension->extensionOffset = 0;
 
-    unsigned ext_index = graph.new_node (&buffer[start], &buffer[end]);
+    unsigned type_prime = extension->extensionLookupType;
+    printf("Assigned type %d to extension\n", type_prime);
+
+    unsigned ext_index = graph.new_node (&buffer.arrayZ[start],
+                                         &buffer.arrayZ[end]);
     if (ext_index == (unsigned) -1) return false;
 
     auto& lookup_vertex = graph.vertices_[lookup_index];
@@ -142,6 +146,7 @@
     l->position = 4;
     l->bias = 0;
 
+    ext_vertex.parents.push (lookup_index);
     subtable_vertex.remap_parent (lookup_index, ext_index);
 
     return true;