Add regression test for #2563.

tests/test_paste.py

@@ -1,5 +1,6 @@
 from textual import events
 from textual.app import App
+from textual.widgets import Input
 
 
 async def test_paste_app():
@@ -16,3 +17,28 @@ async def test_paste_app():
 
     assert len(paste_events) == 1
     assert paste_events[0].text == "Hello"
+
+
+async def test_empty_paste():
+    """Regression test for https://github.com/Textualize/textual/issues/2563."""
+
+    paste_events = []
+
+    class MyInput(Input):
+        def on_paste(self, event):
+            super()._on_paste(event)
+            paste_events.append(event)
+
+    class PasteApp(App):
+        def compose(self):
+            yield MyInput()
+
+        def key_p(self):
+            self.query_one(MyInput).post_message(events.Paste(""))
+
+    app = PasteApp()
+    async with app.run_test() as pilot:
+        await pilot.press("p")
+        assert app.query_one(MyInput).value == ""
+        assert len(paste_events) == 1
+        assert paste_events[0].text == ""