fix: replace selected ranges instead of ignoring visual paste

tests/paste_shapes.rs

@@ -42,6 +42,62 @@ fn keys(editor: &mut Editor, text: &str) {
     }
 }
 
+#[test]
+fn visual_paste_replaces_selection_and_preserves_clipboard_and_undo() {
+    for paste in ['p', 'P'] {
+        for (yank, select, expected) in [
+            ("vly", "j0vl", "XY\nXYc\nend"),
+            ("vly", "j0lvh", "XY\nXYc\nend"),
+            ("yy", "j0vl", "XY\nXY\nc\nend"),
+            ("yy", "jV", "XY\nXY\nend"),
+            ("vly", "jV", "XY\nXYend"),
+        ] {
+            let fixture = Fixture::new();
+            let source = "XY\nabc\nend";
+            let mut editor = fixture.editor(source);
+            keys(&mut editor, yank);
+            keys(&mut editor, select);
+            editor.handle(Input::Char(paste));
+            assert_eq!(editor.context().text, expected, "{yank} {select} {paste}");
+            assert_eq!(editor.mode(), Mode::Normal);
+            keys(&mut editor, "u");
+            assert_eq!(editor.context().text, source);
+            keys(&mut editor, "U");
+            assert_eq!(editor.context().text, expected);
+            keys(
+                &mut editor,
+                if select.ends_with("vh") {
+                    "u0l."
+                } else {
+                    "u0."
+                },
+            );
+            assert_eq!(
+                editor.context().text,
+                expected,
+                "repeat: {yank} {select} {paste}"
+            );
+            keys(&mut editor, "u");
+            keys(&mut editor, select.trim_start_matches('j'));
+            editor.handle(Input::Char(paste));
+            assert_eq!(editor.context().text, expected, "clipboard stays unchanged");
+        }
+    }
+}
+
+#[test]
+fn visual_paste_replaces_every_selected_range_in_one_undo_group() {
+    let fixture = Fixture::new();
+    let source = "XY\n界e\u{301}\n👩‍🚀z";
+    let mut editor = fixture.editor(source);
+    keys(&mut editor, "vlyj0vl");
+    editor.handle(Input::Ctrl('e'));
+    keys(&mut editor, "p");
+    assert_eq!(editor.context().text, "XY\nXY\nXY");
+    keys(&mut editor, "u");
+    assert_eq!(editor.context().text, source);
+}
+
 #[test]
 fn whole_line_yank_pastes_above_or_below_the_target_and_keeps_indentation() {
     let source = " \t界e\u{301}👩‍🚀\nother\nlast\n";