[map] Protect more against pointer deref

diff --git a/src/hb-map.hh b/src/hb-map.hh
index 9883c0d..834a994 100644 (file)
--- a/src/hb-map.hh
+++ b/src/hb-map.hh
@@ -63,6 +63,7 @@ struct hb_hashmap_t
     bool operator == (const item_t &o) { return *this == o.key; }
     bool is_unused () const    { return key == kINVALID; }
     bool is_tombstone () const { return key != kINVALID && value == vINVALID; }
+    bool is_real () const { return key != kINVALID && value != vINVALID; }
   };
 
   hb_object_header_t header;
@@ -136,7 +137,7 @@ struct hb_hashmap_t
     /* Insert back old items. */
     if (old_items)
       for (unsigned int i = 0; i < old_size; i++)
-       if (old_items[i].key != kINVALID && old_items[i].value != vINVALID)
+       if (old_items[i].is_real ())
          set (old_items[i].key, old_items[i].value);
 
     free (old_items);
@@ -173,7 +174,7 @@ struct hb_hashmap_t
   {
     if (unlikely (!items)) return vINVALID;
     unsigned int i = bucket_for (key);
-    return !items[i].is_unused () && items[i] == key ? items[i].value : vINVALID;
+    return items[i].is_real () && items[i] == key ? items[i].value : vINVALID;
   }
 
   void del (K key) { set (key, vINVALID); }