Asynchronous rescan on device change.

src/modules/partition/gui/ChoicePage.cpp

@@ -306,11 +306,28 @@ ChoicePage::applyDeviceChoice()
 
     if ( m_core->isDirty() )
     {
+        ScanningDialog::run( QtConcurrent::run( [ = ]
+        {
+            QMutexLocker locker( &m_coreMutex );
             m_core->revertAllDevices();
+        } ),
+        [ this ]
+        {
+            continueApplyDeviceChoice();
+        },
+        this );
+    }
+    else
+    {
+        continueApplyDeviceChoice();
+    }
 }
 
-    Device* currd = selectedDevice();
 
+void
+ChoicePage::continueApplyDeviceChoice()
+{
+    Device* currd = selectedDevice();
 
     // The device should only be nullptr immediately after a PCM reset.
     // applyDeviceChoice() will be called again momentarily as soon as we handle the

src/modules/partition/gui/ChoicePage.h

@@ -81,6 +81,7 @@ private:
     QComboBox* createBootloaderComboBox( QWidget* parentButton );
     Device* selectedDevice();
     void applyDeviceChoice();
+    void continueApplyDeviceChoice();
     void updateDeviceStatePreview();
     void applyActionChoice( ChoicePage::Choice choice );
     void updateActionChoicePreview( ChoicePage::Choice choice );