Index: src/incidencedialog.cpp
===================================================================
--- src/incidencedialog.cpp
+++ src/incidencedialog.cpp
@@ -88,6 +88,7 @@
     IncidenceRecurrence *mIeRecurrence = nullptr;
     IncidenceResource *mIeResource = nullptr;
     bool mInitiallyDirty = false;
+    bool mRejected = false; // if the user rejected the dialog
     Akonadi::Item mItem;
     QString typeToString(const int type) const;
 
@@ -755,14 +756,18 @@
     KConfigGroup group(KSharedConfig::openConfig(), "IncidenceDialog");
     group.writeEntry("Size", size());
 
+    Q_D(IncidenceDialog);
+    if (!d->mRejected) {
         const Akonadi::Collection col = d_ptr->mCalSelector->currentCollection();
-    // col might not be valid if the collection wasn't found yet (the combo is async), skip saving in that case
+        // col might not be valid if the collection wasn't found yet (the combo is async),
+        // skip saving in that case
         if (col.isValid()
           && col.id() != IncidenceEditorNG::IncidenceEditorSettings::self()->lastSelectedFolder()) {
             IncidenceEditorNG::IncidenceEditorSettings::self()->setLastSelectedFolder(col.id());
             IncidenceEditorNG::IncidenceEditorSettings::self()->save();
         }
     }
+}
 
 void IncidenceDialog::readConfig()
 {
@@ -835,8 +840,10 @@
                 this,
                 i18nc("@info", "Do you really want to cancel?"),
                 i18nc("@title:window", "KOrganizer Confirmation")) == KMessageBox::Yes) {
+            d->mRejected = true;
             QDialog::reject(); // Discard current changes
         } else if (!d->isDirty()) {
+            d->mRejected = true;
             QDialog::reject(); // No pending changes, just close the dialog.
         } // else { // the user wasn't finished editing after all }
     } else if (d->mUi->buttonBox->button(QDialogButtonBox::RestoreDefaults)) {
@@ -854,8 +861,10 @@
             this,
             i18nc("@info", "Do you really want to cancel?"),
             i18nc("@title:window", "KOrganizer Confirmation")) == KMessageBox::Yes) {
+        d->mRejected = true;
         QDialog::reject(); // Discard current changes
     } else if (!d->isDirty()) {
+        d->mRejected = true;
         QDialog::reject(); // No pending changes, just close the dialog.
     }
 }
@@ -868,9 +877,11 @@
             this,
             i18nc("@info", "Do you really want to cancel?"),
             i18nc("@title:window", "KOrganizer Confirmation")) == KMessageBox::Yes) {
+        d->mRejected = true;
         QDialog::reject(); // Discard current changes
         QDialog::closeEvent(event);
     } else if (!d->isDirty()) {
+        d->mRejected = true;
         QDialog::reject(); // No pending changes, just close the dialog.
         QDialog::closeEvent(event);
     } else {