gh-15329: Prevent split view preview from opening for multiple tabs (gh-15340)

src/zen/split-view/ZenViewSplitter.mjs

@@ -336,7 +336,9 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
       if (
         !gBrowser.isTab(draggedTab) ||
         gBrowser.selectedTab.hasAttribute("zen-empty-tab") ||
-        draggedTab.documentGlobal !== window
+        draggedTab.documentGlobal !== window ||
+        // See gh-15329.
+        draggedTab.multiselected
       ) {
         return;
       }

src/zen/sync/ZenSpacesSyncApplier.sys.mjs

@@ -526,9 +526,6 @@ class nsZenSpacesSyncApplier {
         if (!folder?.isZenFolder) {
           continue;
         }
-        // Members without their own tombstone survive: unpack, then delete
-        // the (now empty) folder.
-        await folder.unpackTabs();
         await folder.delete();
       } catch (e) {
         fail(record, e);

src/zen/tests/device_sync/browser.toml

@@ -12,6 +12,8 @@ support-files = [
   "head.js",
 ]
 
+["browser_folder_delete.js"]
+
 ["browser_normal_tabs_apply.js"]
 
 ["browser_normal_tabs_projection.js"]

src/zen/tests/device_sync/browser_folder_delete.js

@@ -0,0 +1,100 @@
+/* Any copyright is dedicated to the Public Domain.
+   https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+async function applyFolderWithMembers(fid, memberIds) {
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    folderRecord(fid),
+    ...memberIds.map(id => tabRecord(id, { pinned: true, folderId: fid })),
+  ]);
+  Assert.deepEqual(failed, [], "The folder batch should apply cleanly");
+  const folder = document.getElementById(fid);
+  Assert.ok(folder?.isZenFolder, "The folder should materialize");
+  for (const id of memberIds) {
+    Assert.equal(
+      document.getElementById(id)?.group,
+      folder,
+      `member ${id} should live in the folder`
+    );
+  }
+}
+
+add_task(async function test_FolderTombstoneWithMemberTombstones() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-a-folder";
+  const members = ["test-sync-del-a-1", "test-sync-del-a-2"];
+  await applyFolderWithMembers(fid, members);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tombstone(fid),
+    ...members.map(tombstone),
+  ]);
+  Assert.deepEqual(failed, [], "The tombstone batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  for (const id of members) {
+    Assert.ok(!document.getElementById(id), `member ${id} should be gone`);
+  }
+
+  for (const id of [fid, ...members]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+});
+
+add_task(async function test_FolderTombstoneAloneDeletesMembers() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-b-folder";
+  const members = ["test-sync-del-b-1", "test-sync-del-b-2"];
+  await applyFolderWithMembers(fid, members);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([tombstone(fid)]);
+  Assert.deepEqual(failed, [], "The tombstone batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  for (const id of members) {
+    const tab = document.getElementById(id);
+    Assert.ok(!tab, `member ${id} should be deleted, not orphaned as pinned`);
+  }
+
+  for (const id of [fid, ...members]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+});
+
+add_task(async function test_MemberMovedOutSurvivesFolderTombstone() {
+  await gZenWorkspaces.promiseInitialized;
+  const fid = "test-sync-del-c-folder";
+  const stays = "test-sync-del-c-stays";
+  const moved = "test-sync-del-c-moved";
+  await applyFolderWithMembers(fid, [stays, moved]);
+
+  const failed = await ZenSpacesSyncApplier.applyBatch([
+    tabRecord(moved, { pinned: true, folderId: null }),
+    tombstone(fid),
+  ]);
+  Assert.deepEqual(failed, [], "The batch should apply cleanly");
+  await TestUtils.waitForCondition(
+    () => !document.getElementById(fid),
+    "waiting for the folder to be removed"
+  );
+  const movedTab = document.getElementById(moved);
+  Assert.ok(movedTab, "the moved-out member should survive");
+  Assert.ok(!movedTab.group?.isZenFolder, "and no longer be in a folder");
+  Assert.ok(
+    !document.getElementById(stays),
+    "the member with no surviving record should be deleted"
+  );
+
+  ZenSpacesSyncModel.noteApplied(moved, null);
+  for (const id of [fid, stays]) {
+    ZenSpacesSyncModel.noteApplied(id, null);
+  }
+  if (movedTab) {
+    BrowserTestUtils.removeTab(movedTab);
+  }
+});

src/zen/tests/device_sync/head.js

@@ -22,6 +22,11 @@ const { TestUtils } = ChromeUtils.importESModule(
 const { E10SUtils } = ChromeUtils.importESModule(
   "resource://gre/modules/E10SUtils.sys.mjs"
 );
+const { PromiseTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromiseTestUtils.sys.mjs"
+);
+
+PromiseTestUtils.allowMatchingRejectionsGlobally(/menu-bookmark-tab/);
 
 const NORMAL_TABS_PREF = "zen.spaces-sync.normal-tabs";
 
@@ -47,7 +52,13 @@ async function openSyncableTab(url, { pinned = false } = {}) {
 
 function tabRecord(
   id,
-  { pinned, url = "https://example.com/", current = null, workspaceUuid } = {}
+  {
+    pinned,
+    url = "https://example.com/",
+    current = null,
+    workspaceUuid,
+    folderId = null,
+  } = {}
 ) {
   return {
     id,
@@ -64,7 +75,7 @@ function tabRecord(
         essential: false,
         pinned,
         workspaceUuid: workspaceUuid ?? gZenWorkspaces.activeWorkspace,
-        folderId: null,
+        folderId,
         staticLabel: null,
         hasStaticIcon: false,
         defaultContainer: false,
@@ -72,3 +83,26 @@ function tabRecord(
     },
   };
 }
+
+function folderRecord(id, { name = "Synced folder", workspaceUuid } = {}) {
+  return {
+    id,
+    deleted: false,
+    cleartext: {
+      kind: "folder",
+      data: {
+        folderId: id,
+        name,
+        icon: null,
+        workspaceUuid: workspaceUuid ?? gZenWorkspaces.activeWorkspace,
+        parentFolderId: null,
+        live: null,
+        children: [],
+      },
+    },
+  };
+}
+
+function tombstone(id) {
+  return { id, deleted: true };
+}

src/zen/tests/moz.build

@@ -6,6 +6,7 @@ BROWSER_CHROME_MANIFESTS += [
     "boosts/browser.toml",
     "compact_mode/browser.toml",
     "container_essentials/browser.toml",
+    "device_sync/browser.toml",
     "folders/browser.toml",
     "glance/browser.toml",
     "live-folders/browser.toml",
@@ -16,7 +17,6 @@ BROWSER_CHROME_MANIFESTS += [
     "site_control/browser.toml",
     "space_routing/browser.toml",
     "spaces/browser.toml",
-    "spaces_sync/browser.toml",
     "split_view/browser.toml",
     "tabs/browser.toml",
     "ub-actions/browser.toml",