From ea30122a09ba6d1a7a25627484af89cb6b8d8c6d Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Thu, 20 Feb 2020 12:55:03 +0300
Subject: [PATCH] wallet: rewrite file on save

When we are opening a file, it is expected that
it will be rewritten, not appended to a already existing wallet.
---
 pkg/wallet/wallet.go      |  5 +++++
 pkg/wallet/wallet_test.go | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/pkg/wallet/wallet.go b/pkg/wallet/wallet.go
index fd9c9ab61..8a6826f5b 100644
--- a/pkg/wallet/wallet.go
+++ b/pkg/wallet/wallet.go
@@ -105,6 +105,11 @@ func (w *Wallet) Path() string {
 // that is responsible for saving the data. This can
 // be a buffer, file, etc..
 func (w *Wallet) Save() error {
+	if s, ok := w.rw.(io.Seeker); ok {
+		if _, err := s.Seek(0, 0); err != nil {
+			return err
+		}
+	}
 	return json.NewEncoder(w.rw).Encode(w)
 }
 
diff --git a/pkg/wallet/wallet_test.go b/pkg/wallet/wallet_test.go
index c22972713..eee01b199 100644
--- a/pkg/wallet/wallet_test.go
+++ b/pkg/wallet/wallet_test.go
@@ -90,6 +90,17 @@ func TestSave(t *testing.T) {
 	openedWallet, err := NewWalletFromFile(wallet.path)
 	require.NoError(t, err)
 	require.Equal(t, wallet.Accounts, openedWallet.Accounts)
+
+	t.Run("change and rewrite", func(t *testing.T) {
+		err := openedWallet.CreateAccount("test", "pass")
+		require.NoError(t, err)
+
+		w2, err := NewWalletFromFile(openedWallet.path)
+		require.NoError(t, err)
+		require.Equal(t, 2, len(w2.Accounts))
+		require.NoError(t, w2.Accounts[1].Decrypt("pass"))
+		require.Equal(t, openedWallet.Accounts, w2.Accounts)
+	})
 }
 
 func TestJSONMarshallUnmarshal(t *testing.T) {