[array] Adjust operator !=

src/hb-array.hh

@@ -100,10 +100,9 @@ struct hb_array_t : hb_iter_with_fallback_t<hb_array_t<Type>, Type&>
   /* Ouch. The operator== compares the contents of the array.  For range-based for loops,
    * it's best if we can just compare arrayZ, though comparing contents is still fast,
    * but also would require that Type has operator==.  As such, we optimize this operator
-   * for range-based for loop and just compare arrayZ.  No need to compare length, as we
-   * assume we're only compared to .end(). */
+   * for range-based for loop and just compare arrayZ and length. */
   bool operator != (const hb_array_t& o) const
-  { return arrayZ != o.arrayZ; }
+  { return this->arrayZ != o.arrayZ || this->length != o.length; }
 
   /* Extra operators.
    */
@@ -325,6 +324,8 @@ struct hb_sorted_array_t :
   { hb_array_t<Type> (*this) = o; return *this; }
 
   /* Iterator implementation. */
+
+  /* See comment in hb_array_of::operator != */
   bool operator != (const hb_sorted_array_t& o) const
   { return this->arrayZ != o.arrayZ || this->length != o.length; }