Bugfix: Avoid potential crash from force-unwrap of pointOrigin in pan gesture

firefox-ios/Client/Frontend/Browser/EnhancedTrackingProtection/EnhancedTrackingProtectionVC.swift

@@ -492,7 +492,7 @@ class EnhancedTrackingProtectionMenuVC: UIViewController, Themeable {
         // Setting x based on window calculation because we don't want
         // users to move the frame side ways, only straight up or down
         view.frame.origin = CGPoint(x: originalXPosition,
-                                    y: self.pointOrigin!.y + translation.y)
+                                    y: (self.pointOrigin?.y ?? originalYPosition) + translation.y)
 
         if sender.state == .ended {
             let dragVelocity = sender.velocity(in: view)

firefox-ios/Client/Frontend/TrackingProtection/TrackingProtectionViewController.swift

@@ -704,7 +704,7 @@ class TrackingProtectionViewController: UIViewController,
         // Setting x based on window calculation because we don't want
         // users to move the frame side ways, only straight up or down
         view.frame.origin = CGPoint(x: originalXPosition,
-                                    y: self.pointOrigin!.y + translation.y)
+                                    y: (self.pointOrigin?.y ?? originalYPosition) + translation.y)
 
         if sender.state == .ended {
             let dragVelocity = sender.velocity(in: view)

firefox-ios/firefox-ios-tests/Tests/ClientTests/TrackingProtectionTests/EnhancedTrackingProtectionVCTests.swift

@@ -0,0 +1,95 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/
+
+import XCTest
+import Common
+@testable import Client
+
+@MainActor
+final class EnhancedTrackingProtectionVCTests: XCTestCase {
+    override func setUp() async throws {
+        try await super.setUp()
+        await DependencyHelperMock().bootstrapDependencies()
+    }
+
+    override func tearDown() async throws {
+        DependencyHelperMock().reset()
+        try await super.tearDown()
+    }
+
+    /// Regression test: prior to the fix, `panGestureRecognizerAction` force-unwrapped `pointOrigin`,
+    /// which is only set inside `viewDidLayoutSubviews`. If the pan gesture fired before the first
+    /// layout pass (e.g. after a memory warning or a rapid present/dismiss cycle), the app crashed
+    /// with `EXC_BAD_INSTRUCTION`. The handler must now tolerate a nil `pointOrigin`.
+    func testPanGestureRecognizerAction_beforeLayoutPass_doesNotCrash() {
+        let subject = makeSUT()
+        subject.loadViewIfNeeded()
+        // Intentionally do NOT call viewDidLayoutSubviews -- pointOrigin stays nil.
+
+        let mockGesture = MockPanGestureRecognizer()
+        mockGesture.mockState = .changed
+        mockGesture.mockTranslation = CGPoint(x: 0, y: 50)
+        mockGesture.mockVelocity = .zero
+
+        subject.panGestureRecognizerAction(sender: mockGesture)
+
+        XCTAssertNotNil(subject.view, "View should still exist after gesture without prior layout pass")
+    }
+
+    /// The .ended branch should also be safe when pointOrigin is still nil — both unwrap sites
+    /// must handle the nil case consistently.
+    func testPanGestureRecognizerAction_endedStateBeforeLayout_doesNotCrash() {
+        let subject = makeSUT()
+        subject.loadViewIfNeeded()
+
+        let mockGesture = MockPanGestureRecognizer()
+        mockGesture.mockState = .ended
+        mockGesture.mockTranslation = CGPoint(x: 0, y: 20)
+        mockGesture.mockVelocity = .zero
+
+        subject.panGestureRecognizerAction(sender: mockGesture)
+
+        XCTAssertNotNil(subject.view)
+    }
+
+    // MARK: - Helpers
+
+    private func makeSUT() -> EnhancedTrackingProtectionMenuVC {
+        let viewModel = EnhancedTrackingProtectionMenuVM(
+            url: URL(string: "https://example.com")!,
+            displayTitle: "example.com",
+            connectionSecure: true,
+            globalETPIsEnabled: true,
+            contentBlockerStatus: .noBlockedURLs
+        )
+        return EnhancedTrackingProtectionMenuVC(
+            viewModel: viewModel,
+            windowUUID: .XCTestDefaultUUID
+        )
+    }
+}
+
+/// Test double allowing us to drive the pan gesture handler deterministically.
+private final class MockPanGestureRecognizer: UIPanGestureRecognizer {
+    var mockState: UIGestureRecognizer.State = .began
+    var mockTranslation: CGPoint = .zero
+    var mockVelocity: CGPoint = .zero
+
+    init() {
+        super.init(target: nil, action: nil)
+    }
+
+    override var state: UIGestureRecognizer.State {
+        get { mockState }
+        set { mockState = newValue }
+    }
+
+    override func translation(in view: UIView?) -> CGPoint {
+        return mockTranslation
+    }
+
+    override func velocity(in view: UIView?) -> CGPoint {
+        return mockVelocity
+    }
+}

firefox-ios/firefox-ios-tests/Tests/ClientTests/TrackingProtectionTests/TrackingProtectionViewControllerTests.swift

@@ -0,0 +1,102 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/
+
+import XCTest
+import Common
+@testable import Client
+
+@MainActor
+final class TrackingProtectionViewControllerTests: XCTestCase {
+    private var mockProfile: MockProfile!
+
+    override func setUp() async throws {
+        try await super.setUp()
+        await DependencyHelperMock().bootstrapDependencies()
+        mockProfile = MockProfile()
+    }
+
+    override func tearDown() async throws {
+        mockProfile = nil
+        DependencyHelperMock().reset()
+        try await super.tearDown()
+    }
+
+    /// Regression test: prior to the fix, `panGestureRecognizerAction` force-unwrapped `pointOrigin`,
+    /// which is only set inside `viewDidLayoutSubviews`. If the pan gesture fired before the first
+    /// layout pass (e.g. after a memory warning or a rapid present/dismiss cycle), the app crashed
+    /// with `EXC_BAD_INSTRUCTION`. The handler must now tolerate a nil `pointOrigin`.
+    func testPanGestureRecognizerAction_beforeLayoutPass_doesNotCrash() {
+        let subject = makeSUT()
+        subject.loadViewIfNeeded()
+        // Intentionally do NOT call viewDidLayoutSubviews -- pointOrigin stays nil.
+
+        let mockGesture = MockPanGestureRecognizer()
+        mockGesture.mockState = .changed
+        mockGesture.mockTranslation = CGPoint(x: 0, y: 50)
+        mockGesture.mockVelocity = .zero
+
+        subject.panGestureRecognizerAction(sender: mockGesture)
+
+        XCTAssertNotNil(subject.view, "View should still exist after gesture without prior layout pass")
+    }
+
+    /// The .ended branch should also be safe when pointOrigin is still nil.
+    func testPanGestureRecognizerAction_endedStateBeforeLayout_doesNotCrash() {
+        let subject = makeSUT()
+        subject.loadViewIfNeeded()
+
+        let mockGesture = MockPanGestureRecognizer()
+        mockGesture.mockState = .ended
+        mockGesture.mockTranslation = CGPoint(x: 0, y: 20)
+        mockGesture.mockVelocity = .zero
+
+        subject.panGestureRecognizerAction(sender: mockGesture)
+
+        XCTAssertNotNil(subject.view)
+    }
+
+    // MARK: - Helpers
+
+    private func makeSUT() -> TrackingProtectionViewController {
+        let model = TrackingProtectionModel(
+            userDefaults: nil,
+            url: URL(string: "https://example.com")!,
+            displayTitle: "example.com",
+            connectionSecure: true,
+            globalETPIsEnabled: true,
+            contentBlockerStatus: .noBlockedURLs,
+            contentBlockerStats: nil,
+            selectedTab: nil
+        )
+        return TrackingProtectionViewController(
+            viewModel: model,
+            profile: mockProfile,
+            windowUUID: .XCTestDefaultUUID
+        )
+    }
+}
+
+/// Test double allowing us to drive the pan gesture handler deterministically.
+private final class MockPanGestureRecognizer: UIPanGestureRecognizer {
+    var mockState: UIGestureRecognizer.State = .began
+    var mockTranslation: CGPoint = .zero
+    var mockVelocity: CGPoint = .zero
+
+    init() {
+        super.init(target: nil, action: nil)
+    }
+
+    override var state: UIGestureRecognizer.State {
+        get { mockState }
+        set { mockState = newValue }
+    }
+
+    override func translation(in view: UIView?) -> CGPoint {
+        return mockTranslation
+    }
+
+    override func velocity(in view: UIView?) -> CGPoint {
+        return mockVelocity
+    }
+}