fix(terminal): let Shift+middle-click paste in mouse-tracking panes (#21858)

* fix(terminal): let Shift+middle-click paste in mouse-tracking panes

Follow-up to #21834 (issue #21762). That fix arms the native-paste
suppression window for every terminal middle-click, then returns early
when the pane is in mouse-tracking mode so the TUI performs the paste
from the forwarded mouse report.

xterm's SelectionService.shouldForceSelection deliberately withholds
that report for a shifted click (Option-click on Mac), so the TUI never
pastes. With the native follow-up paste now suppressed as well,
Shift+middle-click in Claude Code, Codex, and other tracking TUIs pasted
nothing at all. Previously Chromium's native paste was the one paste.

Mirror xterm's platform rule: when the click's modifier forces
selection, fall through to Orca's own paste-to-PTY path (stop
propagation, focus, paste) exactly as in a non-tracking pane. The
auxclick handler gates stopPropagation the same way.

* test(terminal): pin Alt+middle-click to the TUI-owned path off Mac

---------

Co-authored-by: bench <bench@example.invalid>

src/renderer/src/components/terminal-pane/issue-21762-tracking-mode-middle-click-double-paste.repro.test.ts

@@ -88,14 +88,17 @@ function buildController(pane: ManagedPane): TerminalPaneContextController {
 
 function fireMiddleMouseDown(
   handler: (event: React.MouseEvent<HTMLDivElement>) => void,
-  target: EventTarget
+  target: EventTarget,
+  modifiers: { shiftKey?: boolean; altKey?: boolean } = {}
 ): { defaultPrevented: boolean; propagationStopped: boolean } {
   let defaultPrevented = false
   let propagationStopped = false
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: test-only stub; the handler only calls button/target/preventDefault/stopPropagation off the event.
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: test-only stub; the handler only reads button/target/shiftKey/altKey and calls preventDefault/stopPropagation off the event.
   handler({
     button: 1,
     target,
+    shiftKey: modifiers.shiftKey ?? false,
+    altKey: modifiers.altKey ?? false,
     preventDefault: () => {
       defaultPrevented = true
     },
@@ -148,4 +151,104 @@ describe('issue 21762: middle-click native-paste suppression in mouse-tracking T
     expect(outcome.propagationStopped).toBe(true)
     expect(pane.terminal.focus).toHaveBeenCalled()
   })
+
+  // Follow-up to #21834: xterm withholds the mouse report for a shifted click
+  // (SelectionService.shouldForceSelection), so the TUI never pastes. Arming
+  // suppression while also returning early would leave nothing pasted at all.
+  describe('Shift+middle-click in a mouse-tracking pane', () => {
+    it("takes Orca's own paste path: stops propagation and focuses the pane", () => {
+      const pane = buildTrackedPane('sgr')
+      const { result } = renderHook(() => useTerminalPaneMobileActions(buildController(pane)))
+
+      const outcome = fireMiddleMouseDown(
+        result.current.handlePrimarySelectionMiddleMouseDown,
+        pane.container,
+        { shiftKey: true }
+      )
+
+      expect(armPrimarySelectionNativePasteSuppressionMock).toHaveBeenCalled()
+      expect(outcome.defaultPrevented).toBe(true)
+      expect(outcome.propagationStopped).toBe(true)
+      expect(pane.terminal.focus).toHaveBeenCalled()
+    })
+
+    it('keeps the unshifted click on the TUI-owned path (no #21762 regression)', () => {
+      const pane = buildTrackedPane('sgr')
+      const { result } = renderHook(() => useTerminalPaneMobileActions(buildController(pane)))
+
+      const outcome = fireMiddleMouseDown(
+        result.current.handlePrimarySelectionMiddleMouseDown,
+        pane.container,
+        { shiftKey: false }
+      )
+
+      expect(armPrimarySelectionNativePasteSuppressionMock).toHaveBeenCalled()
+      expect(outcome.propagationStopped).toBe(false)
+      expect(pane.terminal.focus).not.toHaveBeenCalled()
+    })
+
+    // Guards against collapsing the modifier check to `shiftKey || altKey`:
+    // off Mac, xterm still forwards an Alt+middle-click, so the TUI pastes.
+    it('leaves Alt+middle-click on the TUI-owned path off Mac', () => {
+      const pane = buildTrackedPane('sgr')
+      const { result } = renderHook(() => useTerminalPaneMobileActions(buildController(pane)))
+
+      const outcome = fireMiddleMouseDown(
+        result.current.handlePrimarySelectionMiddleMouseDown,
+        pane.container,
+        { altKey: true }
+      )
+
+      expect(outcome.propagationStopped).toBe(false)
+      expect(pane.terminal.focus).not.toHaveBeenCalled()
+    })
+
+    it('stops auxclick propagation too, matching the mousedown handler', () => {
+      const pane = buildTrackedPane('sgr')
+      const { result } = renderHook(() => useTerminalPaneMobileActions(buildController(pane)))
+
+      const shifted = fireMiddleMouseDown(
+        result.current.handlePrimarySelectionAuxClick,
+        pane.container,
+        {
+          shiftKey: true
+        }
+      )
+      const plain = fireMiddleMouseDown(
+        result.current.handlePrimarySelectionAuxClick,
+        pane.container
+      )
+
+      expect(armPrimarySelectionNativePasteSuppressionMock).toHaveBeenCalledTimes(2)
+      expect(shifted.propagationStopped).toBe(true)
+      expect(plain.propagationStopped).toBe(false)
+    })
+
+    it('on Mac follows xterm: Option, not Shift, forces the terminal to own the click', () => {
+      const userAgent = vi.spyOn(navigator, 'userAgent', 'get')
+      userAgent.mockReturnValue('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)')
+      try {
+        const pane = buildTrackedPane('sgr')
+        const { result } = renderHook(() => useTerminalPaneMobileActions(buildController(pane)))
+
+        const shifted = fireMiddleMouseDown(
+          result.current.handlePrimarySelectionMiddleMouseDown,
+          pane.container,
+          { shiftKey: true }
+        )
+        expect(shifted.propagationStopped).toBe(false)
+        expect(pane.terminal.focus).not.toHaveBeenCalled()
+
+        const optioned = fireMiddleMouseDown(
+          result.current.handlePrimarySelectionMiddleMouseDown,
+          pane.container,
+          { altKey: true }
+        )
+        expect(optioned.propagationStopped).toBe(true)
+        expect(pane.terminal.focus).toHaveBeenCalled()
+      } finally {
+        userAgent.mockRestore()
+      }
+    })
+  })
 })

src/renderer/src/components/terminal-pane/use-terminal-pane-mobile-actions.ts

@@ -20,6 +20,13 @@ import { recordTerminalUserInputForLeaf } from './terminal-input-activity'
 import { splitTerminalPaneWithInheritedCwd } from './terminal-pane-split-with-inherited-cwd'
 import type { TerminalPaneContextController } from './use-terminal-pane-context-actions'
 
+// Why: mirrors xterm's SelectionService.shouldForceSelection — a shifted click
+// (Option-click on Mac, via macOptionClickForcesSelection) is never forwarded
+// as a mouse report, so the TUI cannot paste and Orca must own it instead.
+function terminalForcesSelectionForClick(event: React.MouseEvent): boolean {
+  return navigator.userAgent.includes('Mac') ? event.altKey : event.shiftKey
+}
+
 export function useTerminalPaneMobileActions(controller: TerminalPaneContextController) {
   const {
     cwd,
@@ -127,10 +134,14 @@ export function useTerminalPaneMobileActions(controller: TerminalPaneContextCont
       // (fired on mouseup, not mousedown; see usePrimarySelectionPaste.ts).
       // Only the paste-to-PTY below is gated on tracking mode, since a
       // tracking TUI still needs the click forwarded as a mouse report and
-      // must not have propagation stopped.
+      // must not have propagation stopped — unless the modifier makes xterm
+      // withhold the report, in which case nobody else will paste.
       event.preventDefault()
       armPrimarySelectionNativePasteSuppression()
-      if (targetPane.terminal.modes.mouseTrackingMode !== 'none') {
+      if (
+        targetPane.terminal.modes.mouseTrackingMode !== 'none' &&
+        !terminalForcesSelectionForClick(event)
+      ) {
         return
       }
       const clickedPane = targetPane
@@ -210,7 +221,10 @@ export function useTerminalPaneMobileActions(controller: TerminalPaneContextCont
       }
       event.preventDefault()
       armPrimarySelectionNativePasteSuppression()
-      if (targetPane.terminal.modes.mouseTrackingMode === 'none') {
+      if (
+        targetPane.terminal.modes.mouseTrackingMode === 'none' ||
+        terminalForcesSelectionForClick(event)
+      ) {
         event.stopPropagation()
       }
     },