Don't unnecessarily transform keysequences into strings

Otherwise we cannot interpret them as the original key sequence anymore.
When passing them on they are interpreted as the number key that
represents the numeric value of the key sequence enum.

Change-Id: Idd94ef95bc693cb6d51162dd1994adc953b52e25
Fixes: QTBUG-75572
Reviewed-by: Henning Gründl <henning.gruendl@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

src/quicktemplates2/qquickaction.cpp

@@ -185,7 +185,7 @@ void QQuickActionPrivate::setShortcut(const QVariant &var)
     for (QQuickActionPrivate::ShortcutEntry *entry : qAsConst(shortcutEntries))
         entry->ungrab();
 
-    vshortcut = var.toString();
+    vshortcut = var;
     keySequence = variantToKeySequence(var);
 
     defaultShortcutEntry->grab(keySequence, enabled);

tests/auto/controls/data/tst_action.qml

@@ -165,4 +165,33 @@ TestCase {
         keyClick(Qt.Key_A, Qt.ControlModifier)
         compare(spy.count, 1)
     }
+
+    Component {
+        id: shortcutBinding
+        Item {
+            Action {
+                id: action
+                shortcut: StandardKey.Copy
+            }
+
+            Shortcut {
+                id: indirectShortcut
+                sequence: action.shortcut
+            }
+
+            Shortcut {
+                id: directShortcut
+                sequence: StandardKey.Copy
+            }
+
+            property alias indirect: indirectShortcut;
+            property alias direct: directShortcut
+        }
+    }
+
+    function test_shortcutBinding() {
+        var container = createTemporaryObject(shortcutBinding, testCase);
+        verify(container)
+        compare(container.indirect.nativeText, container.direct.nativeText);
+    }
 }