Don't store the spotify password and instead use sp_session_relogin().

spotifyblob/blob/spotifyclient.cpp

@@ -289,11 +289,19 @@ void SpotifyClient::Login(const QString& username, const QString& password) {
   sp_session_preferred_bitrate(session_, SP_BITRATE_320k);
   sp_session_preferred_offline_bitrate(session_, SP_BITRATE_320k, false);
 
-#if SPOTIFY_API_VERSION < 9
-  sp_session_login(session_, username.toUtf8().constData(), password.toUtf8().constData());
-#else
-  sp_session_login(session_, username.toUtf8().constData(), password.toUtf8().constData(), true);
-#endif
+  if (password.isEmpty()) {
+    sp_error error = sp_session_relogin(session_);
+    if (error != SP_ERROR_OK) {
+      qLog(Warning) << "Tried to relogin but no stored credentials";
+      SendLoginCompleted(false, sp_error_message(error),
+                         spotify_pb::LoginResponse_Error_BadUsernameOrPassword);
+    }
+  } else {
+    sp_session_login(session_,
+                     username.toUtf8().constData(),
+                     password.toUtf8().constData(),
+                     true);  // Remember the password.
+  }
 }
 
 void SpotifyClient::SendLoginCompleted(bool success, const QString& error,

spotifyblob/common/spotifymessages.proto

@@ -26,7 +26,7 @@ option optimize_for = LITE_RUNTIME;
 
 message LoginRequest {
   required string username = 1;
-  required string password = 2;
+  optional string password = 2;
 }
 
 message LoginResponse {

src/internet/spotifyserver.cpp

@@ -80,7 +80,9 @@ void SpotifyServer::Login(const QString& username, const QString& password) {
 
   spotify_pb::LoginRequest* request = message.mutable_login_request();
   request->set_username(DataCommaSizeFromQString(username));
-  request->set_password(DataCommaSizeFromQString(password));
+  if (!password.isEmpty()) {
+    request->set_password(DataCommaSizeFromQString(password));
+  }
 
   SendMessage(message);
 }

src/internet/spotifyservice.cpp

@@ -220,7 +220,7 @@ void SpotifyService::EnsureServerCreated(const QString& username,
     QSettings s;
     s.beginGroup(kSettingsGroup);
 
-    server_->Login(s.value("username").toString(), s.value("password").toString());
+    server_->Login(s.value("username").toString(), QString::null);
   } else {
     server_->Login(username, password);
   }

src/internet/spotifysettingspage.cpp

@@ -100,10 +100,8 @@ void SpotifySettingsPage::Load() {
   s.beginGroup(SpotifyService::kSettingsGroup);
 
   original_username_ = s.value("username").toString();
-  original_password_ = s.value("password").toString();
 
   ui_->username->setText(original_username_);
-  ui_->password->setText(original_password_);
   validated_ = false;
 
   UpdateLoginState();