Fix paste into browser routing to terminal text box (text box beta)

.github/swift-file-length-budget.tsv

@@ -19,7 +19,7 @@
 6255	cmuxTests/GhosttyConfigTests.swift
 6166	Sources/TabManager.swift
 5915	cmuxTests/TerminalAndGhosttyTests.swift
-5809	Sources/TextBoxInput.swift
+5826	Sources/TextBoxInput.swift
 5573	cmuxTests/BrowserConfigTests.swift
 4483	Sources/cmuxApp.swift
 4482	Sources/Panels/FilePreviewPanel.swift
@@ -96,8 +96,8 @@
 1000	cmuxTests/DockSocketLifecycleTests.swift
 982	Packages/Shared/CmuxAgentChat/Tests/CmuxAgentChatTests/ChatConversationStoreTests.swift
 974	Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Sections/AppSection.swift
+964	Sources/App/ShortcutRoutingSupport.swift
 951	Sources/App/TerminalDirectoryOpenSupport.swift
-948	Sources/App/ShortcutRoutingSupport.swift
 947	Sources/TerminalNotificationPolicy.swift
 945	Sources/SessionIndexRegisteredAgents.swift
 944	Sources/CommandPalette/CommandPaletteSettingsToggle.swift

Sources/App/ShortcutRoutingSupport.swift

@@ -614,6 +614,7 @@ func cmuxIsWebInspectorObject(_ object: NSObject) -> Bool {
 private enum BrowserDocumentEditingCommandEquivalent: CaseIterable {
     case copy
     case cut
+    case paste
     case selectAll
     case italic
 
@@ -637,6 +638,18 @@ private enum BrowserDocumentEditingCommandEquivalent: CaseIterable {
                 control: false,
                 keyCode: 7
             )
+        case .paste:
+            // Cmd+V only. Cmd+Shift+V (paste-and-match-style) keeps its own
+            // dedicated path in CmuxWebView; `matches` requires an exact
+            // modifier match so the Shift variant never resolves here.
+            return StoredShortcut(
+                key: "v",
+                command: true,
+                shift: false,
+                option: false,
+                control: false,
+                keyCode: 9
+            )
         case .selectAll:
             return StoredShortcut(
                 key: "a",
@@ -697,8 +710,11 @@ private func browserDocumentEditingCommandEquivalent(for event: NSEvent) -> Brow
 }
 
 /// For browser content, let the focused document/editor try native editing commands
-/// before cmux's menu fallback. Rich web apps often implement copy/cut/select-all
+/// before cmux's menu fallback. Rich web apps often implement copy/cut/paste/select-all
 /// in contentEditable handlers that AppKit's Edit menu path cannot reproduce.
+/// Paste also has to preflight here so the focused web view claims Cmd+V before the
+/// NSWindow.performKeyEquivalent broadcast can hand it to an unfocused text box
+/// (text box beta) in a sibling terminal pane (manaflow-ai/cmux#6380).
 func shouldRouteBrowserDocumentEditingCommandEquivalentThroughWebContentFirst(
     _ event: NSEvent,
     responder: NSResponder? = nil

Sources/TextBoxInput.swift

@@ -4093,13 +4093,30 @@ final class TextBoxInputTextView: NSTextView {
         return onInsertFileURLs(urls, self)
     }
 
+    /// True when this text view currently owns first responder. Gates the
+    /// standard editing shortcuts handled in `performKeyEquivalent`, which is
+    /// broadcast to the whole view tree and must not act for a background
+    /// text box (manaflow-ai/cmux#6380).
+    private var isFirstResponderForEditingShortcuts: Bool {
+        window?.firstResponder === self
+    }
+
     override func performKeyEquivalent(with event: NSEvent) -> Bool {
         guard event.type == .keyDown else {
             return super.performKeyEquivalent(with: event)
         }
         if handleConfiguredTextBoxShortcut(event) {
             return true
         }
+        // `performKeyEquivalent` is broadcast to every view in the window, not
+        // just the first responder. Standard editing shortcuts (Cmd+C/X/V and
+        // undo/redo) must only be claimed while this text view is the focused
+        // editor; otherwise an unfocused text box (text box beta) steals
+        // copy/cut/paste/undo from the focused browser or terminal pane
+        // (manaflow-ai/cmux#6380).
+        guard isFirstResponderForEditingShortcuts else {
+            return super.performKeyEquivalent(with: event)
+        }
         if handleStandardEditShortcut(event) {
             return true
         }

cmux.xcodeproj/project.pbxproj

@@ -92,6 +92,7 @@
 		604500100000000000000005 /* AppDelegate+WindowIdentity.swift in Sources */ = {isa = PBXBuildFile; fileRef = 604500100000000000000006 /* AppDelegate+WindowIdentity.swift */; };
 		A5001093 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = A5001090 /* AppDelegate.swift */; };
 		725746692D9647948561044D /* AppDelegateBareSpaceShortcutRoutingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 17FCD4CC61D54A2F8F2F463D /* AppDelegateBareSpaceShortcutRoutingTests.swift */; };
+		547E4196D38C1FDCD09BD845 /* AppDelegateBrowserPasteShortcutRoutingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 724C78536F73958E79B8DABE /* AppDelegateBrowserPasteShortcutRoutingTests.swift */; };
 		E3309A09 /* AppDelegateEqualizeSplitsShortcutTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = E3309A0A /* AppDelegateEqualizeSplitsShortcutTests.swift */; };
 		F5996001A1B2C3D4E5F60001 /* AppDelegateFileExplorerShortcutRoutingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = F5996001A1B2C3D4E5F60002 /* AppDelegateFileExplorerShortcutRoutingTests.swift */; };
 		2907A0032907A0032907A003 /* AppDelegateIssue2907RoutingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2907A0042907A0042907A004 /* AppDelegateIssue2907RoutingTests.swift */; };
@@ -1460,6 +1461,7 @@
 		604500100000000000000006 /* AppDelegate+WindowIdentity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "AppDelegate+WindowIdentity.swift"; sourceTree = "<group>"; };
 		A5001090 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		17FCD4CC61D54A2F8F2F463D /* AppDelegateBareSpaceShortcutRoutingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegateBareSpaceShortcutRoutingTests.swift; sourceTree = "<group>"; };
+		724C78536F73958E79B8DABE /* AppDelegateBrowserPasteShortcutRoutingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegateBrowserPasteShortcutRoutingTests.swift; sourceTree = "<group>"; };
 		E3309A0A /* AppDelegateEqualizeSplitsShortcutTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegateEqualizeSplitsShortcutTests.swift; sourceTree = "<group>"; };
 		F5996001A1B2C3D4E5F60002 /* AppDelegateFileExplorerShortcutRoutingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegateFileExplorerShortcutRoutingTests.swift; sourceTree = "<group>"; };
 		2907A0042907A0042907A004 /* AppDelegateIssue2907RoutingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegateIssue2907RoutingTests.swift; sourceTree = "<group>"; };
@@ -3761,6 +3763,7 @@
 				FA100001A1B2C3D4E5F60718 /* BrowserImportMappingTests.swift */,
 				F6000001A1B2C3D4E5F60718 /* AppDelegateShortcutRoutingTests.swift */,
 				F5588001A1B2C3D4E5F60718 /* AppDelegateOptionDigitShortcutRoutingTests.swift */,
+				724C78536F73958E79B8DABE /* AppDelegateBrowserPasteShortcutRoutingTests.swift */,
 				6419B0026419B0026419B002 /* AppDelegateShortcutRoutingRepairProbe.swift */,
 				4E6A6F5C1D2B4980A1234567 /* AppDelegateSurfaceShortcutRoutingTests.swift */,
 				6512F0C06512F0C06512F001 /* MainWindowFocusRestoreTests.swift */,
@@ -5377,6 +5380,7 @@
 				A9E030000000000000000002 /* AgentSessionSocketSurfaceTests.swift in Sources */,
 				A9E050000000000000000002 /* AgentSessionWebRendererTests.swift in Sources */,
 				725746692D9647948561044D /* AppDelegateBareSpaceShortcutRoutingTests.swift in Sources */,
+				547E4196D38C1FDCD09BD845 /* AppDelegateBrowserPasteShortcutRoutingTests.swift in Sources */,
 				E3309A09 /* AppDelegateEqualizeSplitsShortcutTests.swift in Sources */,
 				F5996001A1B2C3D4E5F60001 /* AppDelegateFileExplorerShortcutRoutingTests.swift in Sources */,
 				2907A0032907A0032907A003 /* AppDelegateIssue2907RoutingTests.swift in Sources */,

cmuxTests/AppDelegateBrowserPasteShortcutRoutingTests.swift

@@ -0,0 +1,142 @@
+import AppKit
+import Testing
+
+#if canImport(cmux_DEV)
+@testable import cmux_DEV
+#elseif canImport(cmux)
+@testable import cmux
+#endif
+
+private final class BrowserPasteShortcutFocusableTestView: NSView {
+    override var acceptsFirstResponder: Bool { true }
+}
+
+@MainActor
+@Suite(.serialized)
+struct AppDelegateBrowserPasteShortcutRoutingTests {
+    @Test func browserPasteCommandRoutesThroughWebContentFirst() throws {
+        let pasteEvent = try #require(makeKeyEvent(
+            modifierFlags: [.command],
+            characters: "v",
+            charactersIgnoringModifiers: "v",
+            keyCode: 9
+        ))
+
+        #expect(
+            shouldRouteBrowserDocumentEditingCommandEquivalentThroughWebContentFirst(pasteEvent),
+            "Cmd+V should preflight into focused browser web content like copy/cut/select-all"
+        )
+    }
+
+    @Test func textBoxDeclinesPasteShortcutWhenNotFirstResponder() throws {
+        let hostWindow = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 320, height: 80),
+            styleMask: [.borderless],
+            backing: .buffered,
+            defer: false
+        )
+        hostWindow.animationBehavior = .none
+        hostWindow.isReleasedWhenClosed = false
+        defer {
+            hostWindow.orderOut(nil)
+            hostWindow.close()
+        }
+
+        let contentView = NSView(frame: NSRect(x: 0, y: 0, width: 320, height: 80))
+        let otherView = BrowserPasteShortcutFocusableTestView(frame: NSRect(x: 0, y: 40, width: 320, height: 40))
+        let textView = TextBoxInputTextView(frame: NSRect(x: 0, y: 0, width: 320, height: 30))
+        let textBoxScrollView = NSScrollView(frame: NSRect(x: 0, y: 0, width: 320, height: 30))
+        textBoxScrollView.documentView = textView
+        contentView.addSubview(otherView)
+        contentView.addSubview(textBoxScrollView)
+        hostWindow.contentView = contentView
+        hostWindow.makeKeyAndOrderFront(nil)
+
+        #expect(hostWindow.makeFirstResponder(otherView))
+        #expect(hostWindow.firstResponder === otherView)
+
+        let pasteEvent = try #require(makeKeyEvent(
+            modifierFlags: [.command],
+            characters: "v",
+            charactersIgnoringModifiers: "v",
+            keyCode: 9
+        ))
+
+        #expect(
+            !textView.performKeyEquivalent(with: pasteEvent),
+            "Text box must not claim Cmd+V while another view owns first responder"
+        )
+    }
+
+    @Test func textBoxHandlesPasteShortcutWhenFirstResponder() throws {
+        let hostWindow = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 320, height: 80),
+            styleMask: [.borderless],
+            backing: .buffered,
+            defer: false
+        )
+        hostWindow.animationBehavior = .none
+        hostWindow.isReleasedWhenClosed = false
+        defer {
+            hostWindow.orderOut(nil)
+            hostWindow.close()
+        }
+
+        let contentView = NSView(frame: NSRect(x: 0, y: 0, width: 320, height: 80))
+        let textView = TextBoxInputTextView(frame: NSRect(x: 0, y: 0, width: 320, height: 30))
+        let textBoxScrollView = NSScrollView(frame: NSRect(x: 0, y: 0, width: 320, height: 30))
+        textBoxScrollView.documentView = textView
+        contentView.addSubview(textBoxScrollView)
+        hostWindow.contentView = contentView
+        hostWindow.makeKeyAndOrderFront(nil)
+
+        #expect(hostWindow.makeFirstResponder(textView))
+        #expect(hostWindow.firstResponder === textView)
+
+        let pasteEvent = try #require(makeKeyEvent(
+            modifierFlags: [.command],
+            characters: "v",
+            charactersIgnoringModifiers: "v",
+            keyCode: 9
+        ))
+
+        #expect(
+            textView.performKeyEquivalent(with: pasteEvent),
+            "Text box must still handle Cmd+V while it owns first responder"
+        )
+    }
+
+    @Test func browserPlainTextPasteCommandIsNotADocumentEditingPaste() throws {
+        let pasteAsPlainTextEvent = try #require(makeKeyEvent(
+            modifierFlags: [.command, .shift],
+            characters: "v",
+            charactersIgnoringModifiers: "v",
+            keyCode: 9
+        ))
+
+        #expect(
+            !shouldRouteBrowserDocumentEditingCommandEquivalentThroughWebContentFirst(pasteAsPlainTextEvent),
+            "Cmd+Shift+V keeps its dedicated paste-as-plain-text path"
+        )
+    }
+
+    private func makeKeyEvent(
+        modifierFlags: NSEvent.ModifierFlags,
+        characters: String,
+        charactersIgnoringModifiers: String,
+        keyCode: UInt16
+    ) -> NSEvent? {
+        NSEvent.keyEvent(
+            with: .keyDown,
+            location: .zero,
+            modifierFlags: modifierFlags,
+            timestamp: ProcessInfo.processInfo.systemUptime,
+            windowNumber: 0,
+            context: nil,
+            characters: characters,
+            charactersIgnoringModifiers: charactersIgnoringModifiers,
+            isARepeat: false,
+            keyCode: keyCode
+        )
+    }
+}