Really cancel key import when clicking "Cancel"

src/gui/Dialogs/ImportKeys.qml

@@ -3,6 +3,7 @@
 import QtQuick 2.12
 import Qt.labs.platform 1.1
 import "../Popups"
+import "../PythonBridge"
 
 HFileDialogOpener {
     fill: false
@@ -15,27 +16,37 @@ HFileDialogOpener {
 
     property string userId: ""
     property bool importing: false
+    property Future importFuture: null
 
 
     PasswordPopup {
         id: importPasswordPopup
-        details.text: qsTr("Passphrase used to protect this file:")
+        details.text:
+            importing ?
+            qsTr("This might take a while...") :
+            qsTr("Passphrase used to protect this file:")
         okText: qsTr("Import")
 
+        onCancelled: if (importFuture) importFuture.cancel()
+
 
         property url file: ""
 
 
         function verifyPassword(pass, callback) {
             importing  = true
+
+            const call = py.callClientCoro
             const path = file.toString().replace(/^file:\/\//, "")
 
-            py.callClientCoro(userId, "import_keys", [path, pass], () => {
+            importFuture = call(userId, "import_keys", [path, pass], () => {
                 importing    = false
+                importFuture = null
                 callback(true)
 
             }, (type, args, error, traceback, uuid) => {
                 let unknown  = false
+                importFuture = null
 
                 callback(
                     type === "EncryptionError" ?

src/gui/Popups/PasswordPopup.qml

@@ -17,6 +17,9 @@ BoxPopup {
     onOpened: passwordField.forceActiveFocus()
 
 
+    signal cancelled()
+
+
     property bool validateWhileTyping: false
 
     property string acceptedPassword: ""
@@ -54,7 +57,10 @@ BoxPopup {
                 button.loading = false
             })
         },
-        cancel: button => { popup.close() },
+        cancel: button => {
+            popup.close()
+            cancelled()
+        },
     })