qml: OpenWalletDialog: load any wallet if password matches

If the user has wallets with different passwords (non-unified pw) and
enters a password on startup that fails to unlock the recently used
wallet this change will automatically open any other wallet if there
is another wallet that can be unlocked with this password.

electrum/gui/qml/components/OpenWalletDialog.qml

@@ -12,6 +12,7 @@ ElDialog {
 
     property string name
     property string path
+    property bool isStartup
 
     property bool _invalidPassword: false
     property bool _unlockClicked: false
@@ -40,7 +41,7 @@ ElDialog {
 
             InfoTextArea {
                 id: notice
-                text: Daemon.singlePasswordEnabled || !Daemon.currentWallet
+                text: Daemon.singlePasswordEnabled || isStartup
                     ? qsTr('Please enter password')
                     : qsTr('Wallet <b>%1</b> requires password to unlock').arg(name)
                 iconStyle: InfoTextArea.IconStyle.Warn
@@ -94,9 +95,39 @@ ElDialog {
         Daemon.loadWallet(openwalletdialog.path, password.text)
     }
 
+    function maybeUnlockAnyOtherWallet() {
+        // try to open any other wallet with the password the user entered, hack to improve ux for
+        // users with non-unified wallet password.
+        // we should only fall back to opening a random wallet if:
+        // - the user did not select a specific wallet, otherwise this is confusing
+        // - there can be more than one password, otherwise this scan would be pointless
+        if (Daemon.availableWallets.rowCount() <= 1 || password.text === '') {
+            return false
+        }
+        if (Config.walletDidUseSinglePassword) {
+            // the last time the wallet was unlocked all wallets used the same password.
+            // trying to decrypt all of them now is most probably useless.
+            return false
+        }
+        if (!openwalletdialog.isStartup) {
+            return false  // this dialog got opened because the user clicked on a specific wallet
+        }
+        let wallet_paths = Daemon.getWalletsUnlockableWithPassword(password.text)
+        if (wallet_paths && wallet_paths.length > 0) {
+            console.log('could not unlock recent wallet, falling back to: ' + wallet_paths[0])
+            Daemon.loadWallet(wallet_paths[0], password.text)
+            return true
+        }
+        return false
+    }
+
     Connections {
         target: Daemon
         function onWalletRequiresPassword() {
+            if (maybeUnlockAnyOtherWallet()) {
+                password.text = ''  // reset pw so we cannot end up in a loop
+                return
+            }
             console.log('invalid password')
             _invalidPassword = true
             password.tf.forceActiveFocus()

electrum/gui/qml/components/main.qml

@@ -634,12 +634,18 @@ ApplicationWindow
     }
 
     property var _opendialog: undefined
+    property var _opendialog_startup: true
 
     function showOpenWalletDialog(name, path) {
         if (_opendialog == undefined) {
-            _opendialog = openWalletDialog.createObject(app, { name: name, path: path })
+            _opendialog = openWalletDialog.createObject(app, {
+                name: name,
+                path: path,
+                isStartup: _opendialog_startup,
+            })
             _opendialog.closed.connect(function() {
                 _opendialog = undefined
+                _opendialog_startup = false
             })
             _opendialog.open()
         }

electrum/gui/qml/qeconfig.py

@@ -340,6 +340,16 @@ class QEConfig(AuthMixin, QObject):
         """
         return self.config.WALLET_SHOULD_USE_SINGLE_PASSWORD
 
+    walletDidUseSinglePasswordChanged = pyqtSignal()
+    @pyqtProperty(bool, notify=walletDidUseSinglePasswordChanged)
+    def walletDidUseSinglePassword(self):
+        """
+        Allows to guess if this is a unified password instance without having
+        unlocked any wallet yet. Might be out of sync e.g. if wallet files get copied manually.
+        """
+        # TODO: consider removing once encrypted wallet file headers are available
+        return self.config.WALLET_DID_USE_SINGLE_PASSWORD
+
     @pyqtSlot('qint64', result=str)
     @pyqtSlot(QEAmount, result=str)
     def formatSatsForEditing(self, satoshis):

electrum/gui/qml/qedaemon.py

@@ -237,6 +237,7 @@ class QEDaemon(AuthMixin, QObject):
                     self._logger.info(f'use single password: {self._use_single_password}')
                 else:
                     self._logger.info('use single password disabled by config')
+                self.daemon.config.WALLET_DID_USE_SINGLE_PASSWORD = self._use_single_password
 
                 run_hook('load_wallet', wallet)
 

electrum/simple_config.py

@@ -676,6 +676,8 @@ class SimpleConfig(Logger):
     WALLET_UNCONF_UTXO_FREEZE_THRESHOLD_SAT = ConfigVar('unconf_utxo_freeze_threshold', default=5_000, type_=int)
     WALLET_PAYREQ_EXPIRY_SECONDS = ConfigVar('request_expiry', default=invoices.PR_DEFAULT_EXPIRATION_WHEN_CREATING, type_=int)
     WALLET_SHOULD_USE_SINGLE_PASSWORD = ConfigVar('should_use_single_password', default=False, type_=bool)
+    # TODO: consider removing WALLET_DID_USE_SINGLE_PASSWORD once encrypted wallet file headers are available
+    WALLET_DID_USE_SINGLE_PASSWORD = ConfigVar('did_use_single_password', default=False, type_=bool)
     # note: 'use_change' and 'multiple_change' are per-wallet settings
     WALLET_SEND_CHANGE_TO_LIGHTNING = ConfigVar(
         'send_change_to_lightning', default=False, type_=bool,