Add virtual destructor to SproutNote and BaseNote

Also add test to make sure default copy constructors are okay.

src/gtest/test_joinsplit.cpp

@@ -547,3 +547,25 @@ TEST(joinsplit, note_plaintexts)
 
     ASSERT_TRUE(decrypted.memo == note_pt.memo);
 }
+
+TEST(joinsplit, note_class)
+{
+    uint252 a_sk = uint252(uint256S("f6da8716682d600f74fc16bd0187faad6a26b4aa4c24d5c055b216d94516840e"));
+    uint256 a_pk = PRF_addr_a_pk(a_sk);
+    uint256 sk_enc = ZCNoteEncryption::generate_privkey(a_sk);
+    uint256 pk_enc = ZCNoteEncryption::generate_pubkey(sk_enc);
+    PaymentAddress addr_pk(a_pk, pk_enc);
+
+    SproutNote note(a_pk,
+                    1945813,
+                    random_uint256(),
+                    random_uint256());
+
+    SproutNote clone = note;
+    ASSERT_NE(&note, &clone);
+    ASSERT_EQ(note.value(), clone.value());
+    ASSERT_EQ(note.cm(), clone.cm());
+    ASSERT_EQ(note.rho, clone.rho);
+    ASSERT_EQ(note.r, clone.r);
+    ASSERT_EQ(note.a_pk, clone.a_pk);
+}

src/zcash/Note.hpp

@@ -14,6 +14,8 @@ protected:
 public:
     BaseNote() {}
     BaseNote(uint64_t value) : value_(value) {};
+    virtual ~BaseNote() {};
+
     virtual uint256 cm() const {};
     inline uint64_t value() const { return value_; };
 };
@@ -29,6 +31,8 @@ public:
 
     SproutNote();
 
+    virtual ~SproutNote() {};
+
     virtual uint256 cm() const override;
 
     uint256 nullifier(const SpendingKey& a_sk) const;