qml: OpenWalletDialog: load any wallet if password matches

diff --git a/electrum/gui/qml/components/OpenWalletDialog.qml b/electrum/gui/qml/components/OpenWalletDialog.qml
index b6209de..51ec37e 100644
--- a/electrum/gui/qml/components/OpenWalletDialog.qml
+++ b/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()
diff --git a/electrum/gui/qml/components/main.qml b/electrum/gui/qml/components/main.qml
index bf0b0c9..c8d3645 100644
--- a/electrum/gui/qml/components/main.qml
+++ b/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()
         }
diff --git a/electrum/gui/qml/qeconfig.py b/electrum/gui/qml/qeconfig.py
index 9bf2a29..d0d4d79 100644
--- a/electrum/gui/qml/qeconfig.py
+++ b/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):
diff --git a/electrum/gui/qml/qedaemon.py b/electrum/gui/qml/qedaemon.py
index acbe1a7..2b1bfa3 100644
--- a/electrum/gui/qml/qedaemon.py
+++ b/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)
 
diff --git a/electrum/simple_config.py b/electrum/simple_config.py
index 92b11de..a748186 100644
--- a/electrum/simple_config.py
+++ b/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,