A pane close by its terminal handle closes only that pane, even before the window lists it (dark, layout-owner build only) (#30920)

* fix(runtime): main's relisting for a close carries main's tab layout, so a pane close stays a pane close (dark, layout-owner build only)

Co-Authored-By: Claude <noreply@anthropic.com>

* fix(layout-owner): the relist touches only a row it added, with its own copy of the layout

* fix(layout-owner): store the relist's layout only when it changed anything

---------

Co-authored-by: E2E Test <e2e@test.local>
Co-authored-by: Claude <noreply@anthropic.com>

src/main/runtime/orca-runtime-terminal-close-no-widening-layout-owner.test.ts

@@ -0,0 +1,6 @@
+import { vi } from 'vitest'
+
+// The same no-widening table, in a layout-owner build: a close must not widen there either.
+vi.mock('../../shared/layout-owner-switch', () => ({ ORCA_LAYOUT_OWNER_IS_MAIN: true }))
+
+await import('./orca-runtime-terminal-close-no-widening.test')

src/main/runtime/orca-runtime-terminal-close-no-widening.test.ts

@@ -30,6 +30,7 @@ type Condition =
   | 'no-live-pty'
   | 'kill-fails'
   | 'nothing-published'
+  | 'pane-unlisted'
 
 /** The desktop renderer's split tab as it publishes it, with the given PTY bindings. */
 function syncRendererSplit(
@@ -136,6 +137,42 @@ function arrange(entry: Entry, condition: Condition): CloseContinuityHarness {
       ]
     })
   }
+  if (condition === 'pane-unlisted') {
+    // The renderer's list lags main: a sibling row with no layout yet, and none for the closed pane.
+    harness.runtime.syncWindowGraph(1, {
+      tabs: [
+        {
+          tabId: TAB_ID,
+          worktreeId: WORKTREE_ID,
+          title: 'Fixture shell',
+          activeLeafId: SIBLING_LEAF_ID,
+          layout: { type: 'leaf' as const, leafId: SIBLING_LEAF_ID }
+        }
+      ],
+      leaves: [],
+      mobileSessionTabs: [
+        {
+          worktree: WORKTREE_ID,
+          publicationEpoch: 'renderer:pane-unlisted',
+          snapshotVersion: 4,
+          activeGroupId: null,
+          activeTabId: `${TAB_ID}::${SIBLING_LEAF_ID}`,
+          activeTabType: 'terminal' as const,
+          tabs: [
+            {
+              type: 'terminal' as const,
+              id: `${TAB_ID}::${SIBLING_LEAF_ID}`,
+              parentTabId: TAB_ID,
+              leafId: SIBLING_LEAF_ID,
+              ptyId: SIBLING_PTY_ID,
+              title: 'Fixture shell',
+              isActive: true
+            }
+          ]
+        }
+      ]
+    })
+  }
   if (condition === 'kill-fails') {
     harness.kill.mockReturnValue(false)
   }
@@ -221,6 +258,7 @@ const rows: [Entry, Condition][] = [
   ['cli-pty', 'unbound-sibling'],
   // An owner copy with no panes once read as "one pane", so the close took the whole tab.
   ['cli-pty', 'nothing-published'],
+  ['cli-pty', 'pane-unlisted'],
   ['phone-desktop', 'normal'],
   ['phone-desktop', 'pinned'],
   ['phone-desktop', 'unbound-sibling'],

src/main/runtime/terminal/view/layout-owner-close-relisting.ts

@@ -6,6 +6,9 @@ import type { WorkspaceSessionState } from '../../../../shared/workspace-session
 import { makePaneKey, parsePaneKey } from '../../../../shared/stable-pane-id'
 import { terminalLayoutContainsLeaf } from '../../../../shared/workspace-session-pane-ownership'
 import type { ExecutionHostId } from '../../../../shared/execution-host'
+import type { RuntimeMobileSessionTabsSnapshot } from '../../../../shared/runtime-types'
+import type { TerminalLayoutSnapshot } from '../../../../shared/terminal-tab-types'
+import { cloneTerminalLayoutSnapshot } from '../../mobile-session-layout-projection'
 
 type RelistedPane = {
   tabId: string
@@ -28,7 +31,11 @@ export function relistPaneMainBinds(
   host: {
     hostId: (tabId: string) => ExecutionHostId | undefined
     session: (hostId: ExecutionHostId) => WorkspaceSessionState | null | undefined
-    relist: (pty: RuntimePtyWorktreeRecord, pane: RelistedPane) => void
+    relist: (
+      pty: RuntimePtyWorktreeRecord,
+      pane: RelistedPane,
+      layout: TerminalLayoutSnapshot
+    ) => void
   }
 ): void {
   if (
@@ -55,12 +62,44 @@ export function relistPaneMainBinds(
   ) {
     return
   }
-  host.relist(pty, {
-    tabId: pane.tabId,
-    leafId: pane.leafId,
-    title: null,
-    activate: false,
-    selectIfNoActiveTab: false,
-    notify: false
-  })
+  host.relist(
+    pty,
+    {
+      tabId: pane.tabId,
+      leafId: pane.leafId,
+      title: null,
+      activate: false,
+      selectIfNoActiveTab: false,
+      notify: false
+    },
+    layout
+  )
+}
+
+/**
+ * Every row of the relisted pane's tab takes main's layout. A row built for the pane alone holds
+ * only that pane, and a close reading it would take the pane for the tab's last. Under the switch
+ * main writes a split before the window does, so its layout is the tab's newest.
+ */
+export function withMainTabLayout(
+  snapshot: RuntimeMobileSessionTabsSnapshot,
+  relisted: { tabId: string; ptyId: string },
+  layout: TerminalLayoutSnapshot
+): RuntimeMobileSessionTabsSnapshot {
+  const inTab = (row: RuntimeMobileSessionTabsSnapshot['tabs'][number]): boolean =>
+    row.type === 'terminal' && row.parentTabId === relisted.tabId
+  // A relist the membership gate refused leaves the window's rows as they were.
+  if (
+    !snapshot.tabs.some(
+      (row) => inTab(row) && row.type === 'terminal' && row.ptyId === relisted.ptyId
+    )
+  ) {
+    return snapshot
+  }
+  return {
+    ...snapshot,
+    tabs: snapshot.tabs.map((row) =>
+      inTab(row) ? { ...row, parentLayout: cloneTerminalLayoutSnapshot(layout) } : row
+    )
+  }
 }

src/main/runtime/terminal/view/mobile-terminal-surface.ts

@@ -1,6 +1,6 @@
 /* eslint-disable unicorn/no-useless-spread */
 import { ORCA_LAYOUT_OWNER_IS_MAIN } from '../../../../shared/layout-owner-switch'
-import { relistPaneMainBinds } from './layout-owner-close-relisting'
+import { relistPaneMainBinds, withMainTabLayout } from './layout-owner-close-relisting'
 import { OrcaRuntimeWithCreateRuntimeOwnedMobileSessionTerminal } from '../launch/mobile-terminal-owned-create'
 import type { OrcaRuntimeWithResolveTerminalSplitSourceAuthority } from '../launch/terminal-split-source-authority'
 import type {
@@ -145,8 +145,15 @@ export abstract class OrcaRuntimeWithWaitForMobileTerminalSurface extends OrcaRu
       relistPaneMainBinds(authority, live.pty, {
         hostId: (tabId) => this.getWorkspaceSessionHostIdsForTab(authority.worktreeId, tabId)[0],
         session: (hostId) => this.store?.getWorkspaceSession?.(hostId),
-        relist: (pty, pane) =>
+        relist: (pty, pane, layout) => {
           this.publishPtyBackedMobileSessionTerminal(authority.worktreeId, pty, pane)
+          const relisted = this.mobileSessionTabsByWorktree.get(authority.worktreeId)
+          const withLayout =
+            relisted && withMainTabLayout(relisted, { tabId: pane.tabId, ptyId: pty.ptyId }, layout)
+          if (withLayout && withLayout !== relisted) {
+            this.storeMobileSessionSnapshot(authority.worktreeId, withLayout)
+          }
+        }
       })
     }
     const surface = this.findMobileTerminalSurfaceForPty(authority.worktreeId, authority.ptyId)