fix(terminal): execute Return after Korean IME commit (#1671)

* test(terminal): cover Return after Korean IME commit

* fix(terminal): execute Return after Korean IME commit

---------

Co-authored-by: Lawrence Chen <lawrencecchen@users.noreply.github.com>

Sources/GhosttyTerminalView.swift

@@ -5227,6 +5227,26 @@ class GhosttyNSView: NSView, NSUserInterfaceValidations {
                     #endif
                 }
             }
+
+            if shouldSendCommittedIMEConfirmKey(
+                event: translationEvent,
+                markedTextBefore: markedTextBefore
+            ) {
+                keyEvent.consumed_mods = GHOSTTY_MODS_NONE
+                keyEvent.text = nil
+#if DEBUG
+                let ghosttySendStart = ProcessInfo.processInfo.systemUptime
+                _ = sendTimedGhosttyKey(
+                    surface,
+                    keyEvent,
+                    path: "terminal.keyDown.accumulatedConfirmGhosttySend",
+                    event: event
+                )
+                ghosttySendMs += (ProcessInfo.processInfo.systemUptime - ghosttySendStart) * 1000.0
+#else
+                _ = ghostty_surface_key(surface, keyEvent)
+#endif
+            }
         } else {
             // Get the appropriate text for this key event
             // For control characters, this returns the unmodified character
@@ -5487,6 +5507,11 @@ class GhosttyNSView: NSView, NSUserInterfaceValidations {
         return true
     }
 
+    private func shouldSendCommittedIMEConfirmKey(event: NSEvent, markedTextBefore: Bool) -> Bool {
+        guard markedTextBefore, markedText.length == 0 else { return false }
+        return event.keyCode == 36 || event.keyCode == 76
+    }
+
     private func ghosttyKeyEvent(for event: NSEvent, surface: ghostty_surface_t) -> ghostty_input_key_s {
         var keyEvent = ghostty_input_key_s()
         keyEvent.action = GHOSTTY_ACTION_PRESS

cmuxTests/CJKIMEInputTests.swift

@@ -1,5 +1,6 @@
 import XCTest
 import AppKit
+import ObjectiveC.runtime
 
 #if canImport(cmux_DEV)
 @testable import cmux_DEV
@@ -7,6 +8,64 @@ import AppKit
 @testable import cmux
 #endif
 
+private var cjkIMEInterpretKeyEventsSwizzled = false
+private var cjkIMEInterpretKeyEventsHook: ((GhosttyNSView, [NSEvent]) -> Bool)?
+
+private extension GhosttyNSView {
+    @objc func cmuxUnitTest_interpretKeyEvents(_ eventArray: [NSEvent]) {
+        if let hook = cjkIMEInterpretKeyEventsHook, hook(self, eventArray) {
+            return
+        }
+        cmuxUnitTest_interpretKeyEvents(eventArray)
+    }
+}
+
+private func installCJKIMEInterpretKeyEventsSwizzle() {
+    guard !cjkIMEInterpretKeyEventsSwizzled else { return }
+
+    let originalSelector = #selector(GhosttyNSView.interpretKeyEvents(_:))
+    let swizzledSelector = #selector(GhosttyNSView.cmuxUnitTest_interpretKeyEvents(_:))
+
+    guard let originalMethod = class_getInstanceMethod(GhosttyNSView.self, originalSelector),
+          let swizzledMethod = class_getInstanceMethod(GhosttyNSView.self, swizzledSelector) else {
+        fatalError("Unable to locate GhosttyNSView interpretKeyEvents methods for swizzling")
+    }
+
+    let didAddMethod = class_addMethod(
+        GhosttyNSView.self,
+        originalSelector,
+        method_getImplementation(swizzledMethod),
+        method_getTypeEncoding(swizzledMethod)
+    )
+
+    if didAddMethod {
+        class_replaceMethod(
+            GhosttyNSView.self,
+            swizzledSelector,
+            method_getImplementation(originalMethod),
+            method_getTypeEncoding(originalMethod)
+        )
+    } else {
+        method_exchangeImplementations(originalMethod, swizzledMethod)
+    }
+
+    cjkIMEInterpretKeyEventsSwizzled = true
+}
+
+private func findGhosttyNSView(in view: NSView) -> GhosttyNSView? {
+    if let view = view as? GhosttyNSView {
+        return view
+    }
+
+    for subview in view.subviews {
+        if let match = findGhosttyNSView(in: subview) {
+            return match
+        }
+    }
+
+    return nil
+}
+
 // MARK: - NSTextInputClient protocol: marked text (preedit) lifecycle
 
 /// Tests that the GhosttyNSView NSTextInputClient implementation correctly
@@ -932,6 +991,95 @@ final class GhosttySpaceReleaseRegressionTests: XCTestCase {
     }
 }
 
+@MainActor
+final class KoreanIMEReturnCommitRegressionTests: XCTestCase {
+    func testReturnAfterKoreanCommitAlsoSendsReturnToSurface() {
+        _ = NSApplication.shared
+
+        let surface = TerminalSurface(
+            tabId: UUID(),
+            context: GHOSTTY_SURFACE_CONTEXT_SPLIT,
+            configTemplate: nil,
+            workingDirectory: nil
+        )
+        let hostedView = surface.hostedView
+
+        let window = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 360, height: 240),
+            styleMask: [.titled, .closable],
+            backing: .buffered,
+            defer: false
+        )
+        defer {
+            GhosttyNSView.debugGhosttySurfaceKeyEventObserver = nil
+            window.orderOut(nil)
+        }
+
+        guard let contentView = window.contentView else {
+            XCTFail("Expected content view")
+            return
+        }
+
+        hostedView.frame = contentView.bounds
+        hostedView.autoresizingMask = [.width, .height]
+        contentView.addSubview(hostedView)
+
+        window.makeKeyAndOrderFront(nil)
+        window.displayIfNeeded()
+        contentView.layoutSubtreeIfNeeded()
+        hostedView.setVisibleInUI(true)
+        hostedView.setActive(true)
+        RunLoop.current.run(until: Date().addingTimeInterval(0.05))
+
+        guard let view = findGhosttyNSView(in: hostedView) else {
+            XCTFail("Expected hosted GhosttyNSView")
+            return
+        }
+
+        view.setMarkedText("한", selectedRange: NSRange(location: 0, length: 1), replacementRange: NSRange(location: NSNotFound, length: 0))
+
+        installCJKIMEInterpretKeyEventsSwizzle()
+        cjkIMEInterpretKeyEventsHook = { candidateView, _ in
+            guard candidateView === view else { return false }
+            candidateView.insertText("한", replacementRange: NSRange(location: NSNotFound, length: 0))
+            return true
+        }
+        defer {
+            cjkIMEInterpretKeyEventsHook = nil
+        }
+
+        var sawReturnPress = false
+        GhosttyNSView.debugGhosttySurfaceKeyEventObserver = { keyEvent in
+            guard keyEvent.action == GHOSTTY_ACTION_PRESS,
+                  keyEvent.keycode == 36,
+                  keyEvent.text == nil else { return }
+            sawReturnPress = true
+        }
+
+        guard let event = NSEvent.keyEvent(
+            with: .keyDown,
+            location: .zero,
+            modifierFlags: [],
+            timestamp: ProcessInfo.processInfo.systemUptime,
+            windowNumber: window.windowNumber,
+            context: nil,
+            characters: "\r",
+            charactersIgnoringModifiers: "\r",
+            isARepeat: false,
+            keyCode: 36
+        ) else {
+            XCTFail("Failed to create Return event")
+            return
+        }
+
+        window.makeFirstResponder(view)
+        view.keyDown(with: event)
+
+        XCTAssertFalse(view.hasMarkedText(), "Return should commit the active Hangul composition")
+        XCTAssertTrue(sawReturnPress, "Return should still be forwarded after IME commit so the command executes once")
+    }
+}
+
 final class GhosttyBackquoteRegressionTests: XCTestCase {
     func testShiftBackquoteEscFallbackSendsLiteralTilde() {
         _ = NSApplication.shared