fix(project): expire stale file clipboard after OS replacement (#598)

Project Paste could reuse an earlier file copy after another app replaced the OS clipboard, and Cut files stayed dimmed. The tree now tracks the hand-off to the OS clipboard and rechecks it on window focus and just before Paste. A local Copy or Cut is cleared once the OS holds a different or empty file list; failed writes and clipboard read errors keep it. The native adapters now distinguish read failures from empty lists.

In remote windows, Copy and Cut write newline-joined server paths as plain text, tree Paste keeps the server source, and a later OS file list replaces the remote copy and imports those client files. A plain-text replacement stays undetectable there without a clipboard read that may prompt.

Verified on macOS, locally and against a remote host. The Windows clipboard code was not run.

src/features/project-tree/ProjectView.test.tsx

@@ -10,7 +10,7 @@ import { MessagesHost } from "@/workbench/messages";
 import { FileRefactorDialogHost } from "./FileRefactorDialogs";
 import { setRefactorBackendForTests } from "./fileRefactor";
 import { ProjectView } from "./ProjectView";
-import { beginNew } from "./operations";
+import { beginNew, canPaste } from "./operations";
 import { initProjectTree, setViewOption, useProjectTree } from "./store";
 import type { OutlineItem } from "@/bindings";
 import { _emitEditorEvent } from "@/editor/api";
@@ -110,7 +110,7 @@ describe("ProjectView", () => {
     setOsClipboardForTests({
       files: async () => ["/elsewhere/Photo.png"],
       hasFiles: async () => true,
-      setFiles: async () => {},
+      setFiles: async () => false,
     });
     try {
       const { tree, row, rows } = setup();
@@ -127,6 +127,40 @@ describe("ProjectView", () => {
     }
   });
 
+  it("clears cut dimming and disables Paste on focus after the OS clipboard becomes text", async () => {
+    let files: string[] = [];
+    setOsClipboardForTests({
+      files: async () => files,
+      hasFiles: async () => files.length > 0,
+      setFiles: async (paths) => {
+        files = paths;
+        return true;
+      },
+    });
+    try {
+      const { tree, row, rows } = setup();
+      await waitFor(() => expect(rows()).toContain("README.md"));
+      fireEvent.mouseDown(row("README.md"));
+      tree.focus();
+      fireEvent.keyDown(tree, { key: "x", code: "KeyX", metaKey: true });
+      const content = row("README.md").querySelector("[data-project-path]")!;
+      expect(content.className).toMatch(/cut/);
+      await act(async () => {
+        await useProjectTree.getState().clipboard?.osWrite;
+      });
+      files = [];
+      fireEvent.focus(window);
+      await waitFor(() => expect(content.className).not.toMatch(/cut/));
+      expect(useProjectTree.getState().clipboard).toBeNull();
+      expect(canPaste()).toBe(false);
+      fireEvent.keyDown(tree, { key: "v", code: "KeyV", metaKey: true });
+      expect(screen.queryByRole("dialog", { name: "Copy" })).toBeNull();
+      expect(screen.queryByRole("dialog", { name: "Move" })).toBeNull();
+    } finally {
+      setOsClipboardForTests(null);
+    }
+  });
+
   it("opens files on double click and previews on single click only when enabled", async () => {
     const { row, rows } = setup();
     await waitFor(() => expect(rows()).toContain("README.md"));

src/features/project-tree/ProjectView.tsx

@@ -654,8 +654,7 @@ export function ProjectView() {
     };
   }, []);
 
-  // Files copied in Explorer keep Paste usable: the OS clipboard can change
-  // while this window is in the background, so re-ask whenever it comes back.
+  // Reconcile external files and expired Copy/Cut state when returning from another app.
   useEffect(() => {
     void refreshOsClipboard();
     const refresh = () => void refreshOsClipboard();

src/features/project-tree/clipboard.ts

@@ -11,8 +11,8 @@ export interface OsClipboard {
   files(): Promise<string[]>;
   /** Whether the clipboard holds files: cheap, for the Paste item's enabled state. */
   hasFiles(): Promise<boolean>;
-  /** Puts `paths` there, so Explorer can paste them. */
-  setFiles(paths: string[]): Promise<void>;
+  /** True only when the OS accepted the file list; false for unsupported hosts. */
+  setFiles(paths: string[]): Promise<boolean>;
 }
 
 const native: OsClipboard = {
@@ -31,11 +31,12 @@ const native: OsClipboard = {
   },
 
   async setFiles(paths) {
-    if (!isTauri() || !paths.length) return;
+    if (!isTauri() || !paths.length) return false;
     try {
-      await call(commands.clipboardSetFileList(paths));
+      return await call(commands.clipboardSetFileList(paths));
     } catch {
       // The internal clipboard still works; a failed hand-off is not an error.
+      return false;
     }
   },
 };

src/features/project-tree/operations.test.ts

@@ -1,12 +1,20 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { MEMBER_PREFIX, type ProjectNode } from "./model";
-import { importExternal, paste, selectionAfterDelete, transfer } from "./operations";
+import {
+  canPaste,
+  copySelection,
+  importExternal,
+  paste,
+  refreshOsClipboard,
+  selectionAfterDelete,
+  transfer,
+} from "./operations";
 import { IpcError } from "@/platform/ipc";
-import { pendingFileRefactorDialog } from "./FileRefactorDialogs";
+import { closeFileRefactorDialog, pendingFileRefactorDialog } from "./FileRefactorDialogs";
 import { useRemote } from "@/platform/remote";
 import { provideNotificationService } from "@/workbench/contributions";
 import { MemoryFs, setProjectFsForTests } from "./fs";
-import { initProjectTree, loadDir, setClipboard, setSelection } from "./store";
+import { initProjectTree, loadDir, setClipboard, setSelection, useProjectTree } from "./store";
 import { setOsClipboardForTests } from "./clipboard";
 
 let fs: MemoryFs;
@@ -62,7 +70,7 @@ describe("OS file imports", () => {
 
   it("does not paste into the project root when a member row is selected", async () => {
     const files = vi.fn(async () => ["/outside/local.txt"]);
-    setOsClipboardForTests({ files, hasFiles: async () => true, setFiles: async () => {} });
+    setOsClipboardForTests({ files, hasFiles: async () => true, setFiles: async () => false });
     const imported = vi.spyOn(fs, "importLocal");
     const key = `${MEMBER_PREFIX}/p/local.txt\0function:main`;
     setSelection(new Set([key]), key);
@@ -78,7 +86,7 @@ describe("OS file imports", () => {
       setOsClipboardForTests({
         files: async () => ["/p/local.txt"],
         hasFiles: async () => true,
-        setFiles: async () => {},
+        setFiles: async () => false,
       });
       const imported = vi.spyOn(fs, "importLocal");
       for (let i = 0; i < 2; i++) {
@@ -109,7 +117,7 @@ describe("OS file imports", () => {
         throw new Error("clipboard unavailable");
       },
       hasFiles: async () => true,
-      setFiles: async () => {},
+      setFiles: async () => false,
     });
     await paste("/p/target");
     expect(notify).toHaveBeenCalledWith(
@@ -123,7 +131,7 @@ describe("OS file imports", () => {
         throw new Error("busy");
       },
       hasFiles: async () => false,
-      setFiles: async () => {},
+      setFiles: async () => false,
     });
     setClipboard({ paths: ["/p/local.txt"], cut });
     await paste("/p/target");
@@ -156,3 +164,206 @@ describe("OS file imports", () => {
     expect(imported).not.toHaveBeenCalled();
   });
 });
+
+describe("project clipboard ownership", () => {
+  beforeEach(async () => {
+    fs = new MemoryFs({ "/p/target": null, "/p/source.txt": "source", "/other.txt": "other" }, "/p");
+    setProjectFsForTests(fs, "/p");
+    initProjectTree("/p", "p");
+    await loadDir("/p");
+    setSelection(new Set(["/p/source.txt"]), "/p/source.txt");
+    closeFileRefactorDialog();
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    useRemote.setState({ session: null });
+    setProjectFsForTests(null);
+    setOsClipboardForTests(null);
+    closeFileRefactorDialog();
+  });
+
+  const cases = [false, true].flatMap((handedOff) =>
+    ["same", "other", "empty", "error"].flatMap((osList) =>
+      [false, true].flatMap((cut) => ["focus", "paste"].map((entry) => ({ handedOff, osList, cut, entry }))),
+    ),
+  );
+
+  it.each(cases)("hand-off=$handedOff OS=$osList cut=$cut on $entry", async ({ handedOff, osList, cut, entry }) => {
+    const files = vi.fn(async () => {
+      if (osList === "error") throw new Error("busy");
+      return osList === "same" ? ["/p/source.txt"] : osList === "other" ? ["/other.txt"] : [];
+    });
+    const setFiles = vi.fn(async () => handedOff);
+    setOsClipboardForTests({ files, hasFiles: async () => osList === "same" || osList === "other", setFiles });
+    copySelection(cut);
+    const clipboard = useProjectTree.getState().clipboard;
+    expect(clipboard).toEqual(expect.objectContaining({ paths: ["/p/source.txt"], cut }));
+    expect(setFiles).toHaveBeenCalledWith(["/p/source.txt"]);
+    const stale = handedOff && (osList === "other" || osList === "empty");
+    if (entry === "focus") await refreshOsClipboard();
+    else await paste("/p/target");
+    expect(useProjectTree.getState().clipboard).toBe(stale ? null : clipboard);
+    expect(canPaste()).toBe(!(handedOff && osList === "empty"));
+    // canPaste only consults cached state, even when called repeatedly by menus.
+    canPaste();
+    expect(files).toHaveBeenCalledTimes(1);
+    if (entry === "paste") {
+      if (osList === "other") {
+        expect(fs.nodes.has("/p/target/other.txt")).toBe(true);
+        expect(fs.nodes.has("/p/target/source.txt")).toBe(false);
+        expect(pendingFileRefactorDialog()).toBeNull();
+      } else if (stale) {
+        expect(pendingFileRefactorDialog()).toBeNull();
+        expect(fs.nodes.has("/p/target/source.txt")).toBe(false);
+      } else {
+        expect(pendingFileRefactorDialog()).toEqual(
+          expect.objectContaining({ kind: cut ? "move" : "copy", paths: ["/p/source.txt"] }),
+        );
+      }
+    }
+  });
+
+  it.each([false, true])("keeps the internal clipboard after a rejected hand-off (cut=%s)", async (cut) => {
+    setOsClipboardForTests({
+      files: async () => [],
+      hasFiles: async () => false,
+      setFiles: async () => {
+        throw new Error("unavailable");
+      },
+    });
+    copySelection(cut);
+    await refreshOsClipboard();
+    await paste("/p/target");
+    expect(pendingFileRefactorDialog()?.kind).toBe(cut ? "move" : "copy");
+  });
+
+  const remoteCases = [false, true].flatMap((handedOff) =>
+    ["same", "other", "empty", "error"].flatMap((osList) =>
+      [false, true].flatMap((cut) => ["focus", "paste"].map((entry) => ({ handedOff, osList, cut, entry }))),
+    ),
+  );
+
+  it.each(remoteCases)(
+    "remote hand-off=$handedOff OS=$osList cut=$cut on $entry",
+    async ({ handedOff, osList, cut, entry }) => {
+      useRemote.setState({ session: { sshConfig: "ssh", root: "/p", host: "host", commands: ["fs_copy"] } });
+      const writeText = vi.fn(async () => {
+        if (!handedOff) throw new Error("unavailable");
+      });
+      vi.stubGlobal("navigator", { clipboard: { writeText } });
+      const setFiles = vi.fn(async () => true);
+      const files = vi.fn(async () => {
+        if (osList === "error") throw new Error("busy");
+        return osList === "same" ? ["/p/source.txt"] : osList === "other" ? ["/other.txt"] : [];
+      });
+      setOsClipboardForTests({ files, hasFiles: async () => false, setFiles });
+      copySelection(cut);
+      const clipboard = useProjectTree.getState().clipboard;
+      const stale = handedOff && (osList === "same" || osList === "other");
+      const copied = vi.spyOn(fs, "copy");
+      const imported = vi.spyOn(fs, "importLocal").mockResolvedValue([]);
+      if (entry === "focus") await refreshOsClipboard();
+      else await paste("/p/target");
+      expect(writeText).toHaveBeenCalledWith("/p/source.txt");
+      expect(setFiles).not.toHaveBeenCalled();
+      expect(files).toHaveBeenCalledTimes(1);
+      expect(useProjectTree.getState().clipboard).toBe(stale ? null : clipboard);
+      expect(canPaste()).toBe(true);
+      if (entry === "paste") {
+        if (stale) {
+          expect(imported).toHaveBeenCalledWith(
+            osList === "same" ? "/p/source.txt" : "/other.txt",
+            osList === "same" ? "/p/target/source.txt" : "/p/target/other.txt",
+            expect.anything(),
+          );
+          expect(pendingFileRefactorDialog()).toBeNull();
+          expect(copied).not.toHaveBeenCalled();
+        } else {
+          const dialog = pendingFileRefactorDialog()!;
+          expect(dialog).toEqual(expect.objectContaining({ kind: cut ? "move" : "copy", paths: ["/p/source.txt"] }));
+          if (dialog.kind === "copy") {
+            await dialog.copy("/p/target", null, false);
+            expect(copied).toHaveBeenCalledWith("/p/source.txt", "/p/target/source.txt");
+          }
+          expect(imported).not.toHaveBeenCalled();
+        }
+      }
+    },
+  );
+
+  it("writes multiple remote paths as newline-joined text", async () => {
+    useRemote.setState({ session: { sshConfig: "ssh", root: "/p", host: "host", commands: ["fs_copy"] } });
+    await fs.createFile("/p/second.txt");
+    await loadDir("/p", true);
+    setSelection(new Set(["/p/source.txt", "/p/second.txt"]), "/p/source.txt");
+    const writeText = vi.fn(async () => {});
+    vi.stubGlobal("navigator", { clipboard: { writeText } });
+    copySelection(false);
+    expect(await useProjectTree.getState().clipboard?.osWrite).toBe(true);
+    expect(writeText).toHaveBeenCalledWith("/p/source.txt\n/p/second.txt");
+  });
+
+  it("waits for a pending remote text write before reading file URLs", async () => {
+    useRemote.setState({ session: { sshConfig: "ssh", root: "/p", host: "host", commands: ["fs_copy"] } });
+    let finish!: () => void;
+    vi.stubGlobal("navigator", {
+      clipboard: {
+        writeText: () =>
+          new Promise<void>((resolve) => {
+            finish = resolve;
+          }),
+      },
+    });
+    const files = vi.fn(async () => []);
+    setOsClipboardForTests({ files, hasFiles: async () => false, setFiles: async () => true });
+    copySelection(false);
+    const refreshing = refreshOsClipboard();
+    await Promise.resolve();
+    expect(files).not.toHaveBeenCalled();
+    finish();
+    await refreshing;
+    expect(useProjectTree.getState().clipboard?.remote).toBe(true);
+  });
+
+  it("waits for the hand-off before reading the OS clipboard", async () => {
+    let finish!: (written: boolean) => void;
+    const files = vi.fn(async () => ["/p/source.txt"]);
+    setOsClipboardForTests({
+      files,
+      hasFiles: async () => false,
+      setFiles: () =>
+        new Promise((r) => {
+          finish = r;
+        }),
+    });
+    copySelection(true);
+    const refreshing = refreshOsClipboard();
+    await Promise.resolve();
+    expect(files).not.toHaveBeenCalled();
+    finish(true);
+    await refreshing;
+    expect(useProjectTree.getState().clipboard?.cut).toBe(true);
+  });
+
+  it("ignores a stale read that completes after a newer Copy", async () => {
+    let finish!: (paths: string[]) => void;
+    setOsClipboardForTests({
+      files: () =>
+        new Promise((r) => {
+          finish = r;
+        }),
+      hasFiles: async () => true,
+      setFiles: async () => true,
+    });
+    copySelection(true);
+    const refreshing = refreshOsClipboard();
+    await vi.waitFor(() => expect(finish).toBeTypeOf("function"));
+    copySelection(false);
+    const newer = useProjectTree.getState().clipboard;
+    finish([]);
+    await refreshing;
+    expect(useProjectTree.getState().clipboard).toBe(newer);
+    expect(canPaste()).toBe(true);
+  });
+});

src/features/project-tree/operations.ts

@@ -479,9 +479,14 @@ export async function deleteSelection(nodes: ProjectNode[] = selectedNodes()) {
 export function copySelection(cut: boolean) {
   const paths = topLevelPaths(selectedNodes().filter((n) => (cut ? mutable(n) : !n.root && !n.group)));
   if (!paths.length) return;
-  setClipboard({ paths, cut });
-  // Hand the files to the OS too, so Explorer can paste them (as IDEA does).
-  void osClipboard().setFiles(paths);
+  // Remote paths are useful as text, but do not name files on the client.
+  const remote = isRemoteWindow();
+  const osWrite = (async () => {
+    if (!remote) return osClipboard().setFiles(paths);
+    await navigator.clipboard.writeText(paths.join("\n"));
+    return true;
+  })().catch(() => false);
+  setClipboard({ paths, cut, remote, osWrite });
 }
 
 /** Files on the OS clipboard, cached: `canPaste` runs while a menu renders. */
@@ -489,7 +494,25 @@ let osHasFiles = false;
 
 /** Keeps Paste enabled for what Explorer copied; called when the window gains focus. */
 export async function refreshOsClipboard() {
-  osHasFiles = await osClipboard().hasFiles();
+  try {
+    await readOsClipboard();
+  } catch {
+    // A busy clipboard is not evidence that the user's copy has changed.
+  }
+}
+
+async function readOsClipboard(): Promise<string[] | null> {
+  const { clipboard } = get();
+  const handedOff = await clipboard?.osWrite;
+  const external = await osClipboard().files();
+  // A newer Copy/Cut owns the state if this read (or its hand-off) was delayed.
+  if (get().clipboard !== clipboard) return null;
+  osHasFiles = external.length > 0;
+  // Our remote text write removes file URLs, so any files were copied later.
+  // A failed write leaves ownership uncertain; retain the remote copy then.
+  if (handedOff && (clipboard?.remote ? external.length > 0 : !sameFiles(external, clipboard?.paths)))
+    setClipboard(null);
+  return external;
 }
 
 export function canPaste(): boolean {
@@ -501,20 +524,23 @@ export function canPaste(): boolean {
  * dialog (IDEA). Files copied in Explorer paste as copies.
  */
 export async function paste(target = targetFolder()) {
-  const { clipboard } = get();
   if (!target || isReadOnlyPath(target)) return;
   let external: string[] = [];
   try {
-    external = await osClipboard().files();
+    const files = await readOsClipboard();
+    if (files === null) return;
+    external = files;
   } catch (e) {
-    if (!clipboard?.paths.length) {
+    if (!get().clipboard?.paths.length) {
       fail("Cannot access the clipboard", e);
       return;
     }
   }
+  const { clipboard } = get();
   // The last copy is the one the user expects to paste, so another app's files
   // win over ours — unless they are the copy we handed to the OS ourselves.
-  if (external.length && !sameFiles(external, clipboard?.paths)) return pasteFromOsClipboard(external, target);
+  if (!clipboard?.remote && external.length && !sameFiles(external, clipboard?.paths))
+    return pasteFromOsClipboard(external, target);
   if (!clipboard?.paths.length) {
     notifications().notify({ level: "info", title: "No files on the clipboard" });
     return;

src/features/project-tree/store.ts

@@ -87,6 +87,10 @@ export type Editing =
 export interface Clipboard {
   paths: string[];
   cut: boolean;
+  /** Server paths cannot be represented by the client's OS file list. */
+  remote?: boolean;
+  /** Pending OS hand-off, so a read cannot invalidate this copy before its write finishes. */
+  osWrite?: Promise<boolean>;
 }
 
 interface ProjectTreeState {