Use pane TTY fallback for tmux Shift+Enter

Sources/GhosttyTerminalView.swift

@@ -1930,12 +1930,10 @@ class GhosttyApp {
         modifierFlags: NSEvent.ModifierFlags,
         isInsideTmux: Bool,
         userConfigDefinesShiftEnterBinding: Bool,
-        ghosttyHasBinding: Bool,
         hasMarkedText: Bool
     ) -> Bool {
         guard isInsideTmux else { return false }
         guard !userConfigDefinesShiftEnterBinding else { return false }
-        guard !ghosttyHasBinding else { return false }
         guard !hasMarkedText else { return false }
 
         let normalizedModifiers = terminalKeyboardCopyModeNormalizedModifiers(modifierFlags)
@@ -6236,27 +6234,44 @@ class GhosttyNSView: NSView, NSUserInterfaceValidations {
         event: NSEvent,
         surface: ghostty_surface_t
     ) -> Bool {
-        guard !GhosttyApp.shared.userConfigDefinesShiftEnterBinding else { return false }
+        let userConfigDefinesShiftEnterBinding = GhosttyApp.shared.userConfigDefinesShiftEnterBinding
+        guard !userConfigDefinesShiftEnterBinding else { return false }
         let normalizedModifiers = terminalKeyboardCopyModeNormalizedModifiers(event.modifierFlags)
         guard normalizedModifiers == [.shift] else { return false }
         guard event.keyCode == 36 || event.keyCode == 76 else { return false }
         guard let terminalSurface else { return false }
         let tabId = terminalSurface.tabId
         let panelId = terminalSurface.id
-        let isInsideTmux = AppDelegate.shared?
+        guard let tab = AppDelegate.shared?
             .tabManagerFor(tabId: tabId)?
             .tabs
-            .first(where: { $0.id == tabId })?
+            .first(where: { $0.id == tabId }) else {
-            .panelIsInsideTmux(panelId: panelId) ?? false
+            return false
-        let ghosttyHasBinding = ghosttyBindingFlags(for: event, surface: surface) != nil
+        }
-        return GhosttyApp.shouldRemapShiftEnterForTmux(
+        let reportedInsideTmux = tab.panelIsInsideTmux(panelId: panelId)
+        // Shell-side tmux telemetry can lag behind pane focus changes, so fall back to
+        // the current foreground process on the pane TTY before deciding whether to remap.
+        let detectedInsideTmux = tab.surfaceTTYNames[panelId].map {
+            TerminalSSHSessionDetector.isInsideTmux(forTTY: $0)
+        } ?? false
+        let isInsideTmux = reportedInsideTmux || detectedInsideTmux
+        if detectedInsideTmux != reportedInsideTmux {
+            AppDelegate.shared?
+                .tabManagerFor(tabId: tabId)?
+                .updateSurfaceTmuxState(
+                    tabId: tabId,
+                    surfaceId: panelId,
+                    isInsideTmux: detectedInsideTmux
+                )
+        }
+        let shouldRemap = GhosttyApp.shouldRemapShiftEnterForTmux(
             keyCode: event.keyCode,
             modifierFlags: event.modifierFlags,
             isInsideTmux: isInsideTmux,
-            userConfigDefinesShiftEnterBinding: false,
+            userConfigDefinesShiftEnterBinding: userConfigDefinesShiftEnterBinding,
-            ghosttyHasBinding: ghosttyHasBinding,
             hasMarkedText: hasMarkedText()
         )
+        return shouldRemap
     }
 
 #if DEBUG

Sources/TerminalSSHSessionDetector.swift

@@ -420,6 +420,24 @@ enum TerminalSSHSessionDetector {
         )
     }
 
+    static func isInsideTmux(forTTY ttyName: String) -> Bool {
+        let normalizedTTY = normalizeTTYName(ttyName)
+        guard !normalizedTTY.isEmpty else { return false }
+        return isInsideTmuxForTesting(
+            ttyName: normalizedTTY,
+            processes: processSnapshots(forTTY: normalizedTTY)
+        )
+    }
+
+    static func isInsideTmuxForTesting(
+        ttyName: String,
+        processes: [ProcessSnapshot]
+    ) -> Bool {
+        let normalizedTTY = normalizeTTYName(ttyName)
+        guard !normalizedTTY.isEmpty else { return false }
+        return processes.contains { isForegroundProcess($0, ttyName: normalizedTTY, executableName: "tmux") }
+    }
+
     static func detectForTesting(
         ttyName: String,
         processes: [ProcessSnapshot],
@@ -474,8 +492,16 @@ enum TerminalSSHSessionDetector {
     }
 
     private static func isForegroundSSHProcess(_ process: ProcessSnapshot, ttyName: String) -> Bool {
+        isForegroundProcess(process, ttyName: ttyName, executableName: "ssh")
+    }
+
+    private static func isForegroundProcess(
+        _ process: ProcessSnapshot,
+        ttyName: String,
+        executableName: String
+    ) -> Bool {
         normalizeTTYName(process.tty) == normalizeTTYName(ttyName) &&
-            process.executableName == "ssh" &&
+            process.executableName == executableName &&
             process.pgid > 0 &&
             process.tpgid > 0 &&
             process.pgid == process.tpgid

cmuxTests/GhosttyConfigTests.swift

@@ -2559,7 +2559,6 @@ final class GhosttyMouseFocusTests: XCTestCase {
                 modifierFlags: [.shift],
                 isInsideTmux: true,
                 userConfigDefinesShiftEnterBinding: false,
-                ghosttyHasBinding: false,
                 hasMarkedText: false
             )
         )
@@ -2570,7 +2569,6 @@ final class GhosttyMouseFocusTests: XCTestCase {
                 modifierFlags: [.shift],
                 isInsideTmux: false,
                 userConfigDefinesShiftEnterBinding: false,
-                ghosttyHasBinding: false,
                 hasMarkedText: false
             )
         )
@@ -2581,18 +2579,6 @@ final class GhosttyMouseFocusTests: XCTestCase {
                 modifierFlags: [.shift],
                 isInsideTmux: true,
                 userConfigDefinesShiftEnterBinding: true,
-                ghosttyHasBinding: false,
-                hasMarkedText: false
-            )
-        )
-
-        XCTAssertFalse(
-            GhosttyApp.shouldRemapShiftEnterForTmux(
-                keyCode: 36,
-                modifierFlags: [.shift],
-                isInsideTmux: true,
-                userConfigDefinesShiftEnterBinding: false,
-                ghosttyHasBinding: true,
                 hasMarkedText: false
             )
         )
@@ -2603,12 +2589,56 @@ final class GhosttyMouseFocusTests: XCTestCase {
                 modifierFlags: [.shift, .command],
                 isInsideTmux: true,
                 userConfigDefinesShiftEnterBinding: false,
-                ghosttyHasBinding: false,
                 hasMarkedText: false
             )
         )
     }
 
+    func testForegroundTmuxProcessOnTTYIsDetected() {
+        let processes = [
+            TerminalSSHSessionDetector.ProcessSnapshot(
+                pid: 47486,
+                pgid: 47486,
+                tpgid: 48365,
+                tty: "ttys089",
+                executableName: "login"
+            ),
+            TerminalSSHSessionDetector.ProcessSnapshot(
+                pid: 47487,
+                pgid: 47487,
+                tpgid: 48365,
+                tty: "ttys089",
+                executableName: "zsh"
+            ),
+            TerminalSSHSessionDetector.ProcessSnapshot(
+                pid: 48365,
+                pgid: 48365,
+                tpgid: 48365,
+                tty: "ttys089",
+                executableName: "tmux"
+            ),
+        ]
+
+        XCTAssertTrue(
+            TerminalSSHSessionDetector.isInsideTmuxForTesting(
+                ttyName: "ttys089",
+                processes: processes
+            )
+        )
+        XCTAssertFalse(
+            TerminalSSHSessionDetector.isInsideTmuxForTesting(
+                ttyName: "ttys090",
+                processes: processes
+            )
+        )
+        XCTAssertFalse(
+            TerminalSSHSessionDetector.isInsideTmuxForTesting(
+                ttyName: "ttys089",
+                processes: processes.filter { $0.executableName != "tmux" }
+            )
+        )
+    }
+
     func testLoadedCJKScanPathsSkipsReleaseAppSupportWhenTaggedConfigExists() throws {
         let appSupport = FileManager.default.temporaryDirectory
             .appendingPathComponent("cmux-test-cjk-app-support-\(UUID().uuidString)")