Bug 187926 - WKWebView in a modal presentation dismisses its presenting view controller.
Summary: WKWebView in a modal presentation dismisses its presenting view controller.
Status: RESOLVED DUPLICATE of bug 183549
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: Safari 11
Hardware: iPhone / iPad iOS 11
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-07-23 14:39 PDT by Tom Harrington
Modified: 2018-07-27 10:32 PDT (History)
3 users (show)

See Also:

Attachments
Demo project reproducing this issue. (95.49 KB, application/zip)
2018-07-23 14:39 PDT, Tom Harrington 		no flags Details
View All Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Tom Harrington 2018-07-23 14:39:11 PDT 
Created attachment 345609 [details]
Demo project reproducing this issue.

This is similar to:

- https://bugs.webkit.org/show_bug.cgi?id=165225
- https://bugs.webkit.org/show_bug.cgi?id=185257

However it's still present as of iOS 11.4.1. A minimal sample project is attached.

The behavior is:

1. Present a view controller modally which contains a WKWebView.
2. Load a page in the WKWebView that includes an image.
3. Tap and hold on the image until the save/copy/cancel alert appears.
4. Tap "cancel" in the alert.

Expected behavior: The alert would disappear.

Actual behavior: Both the alert and the view controller presented in step 1 are dismissed.

This appears to happen because dismissViewControllerAnimated:completion: is called twice even though only one alert has been displayed.

The backtrace for the first dismiss call is:

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 4.1
  * frame #0: 0x000000018f006130 UIKit`-[UIViewController dismissViewControllerAnimated:completion:]
    frame #1: 0x000000018f41e1a4 UIKit`__103-[UIAlertController _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:dismissCompletion:]_block_invoke.465 + 248
    frame #2: 0x000000018f005fb4 UIKit`-[UIAlertController _performAction:invokeActionBlock:dismissAndPerformActionIfNotAlreadyPerformed:] + 124
    frame #3: 0x000000018f005b94 UIKit`-[UIAlertController _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:dismissCompletion:] + 824
    frame #4: 0x000000018f005848 UIKit`-[UIAlertController _dismissWithAction:dismissCompletion:] + 68
    frame #5: 0x000000018f0056ec UIKit`-[_UIAlertControllerView interfaceAction:invokeActionHandler:completion:] + 256
    frame #6: 0x000000018f005588 UIKit`-[UIInterfaceActionGroupView interfaceAction:invokeActionHandler:completion:] + 120
    frame #7: 0x000000018f005490 UIKit`-[UIInterfaceAction _invokeHandlerWithCompletionBlock:] + 168
    frame #8: 0x000000018efff2d8 UIKit`-[UIInterfaceActionSelectionTrackingController _handleActionSelectionGestureRecognizer:] + 864
    frame #9: 0x000000018effa6e8 UIKit`-[UIGestureRecognizerTarget _sendActionWithGestureRecognizer:] + 64
    frame #10: 0x000000018f5673b4 UIKit`_UIGestureRecognizerSendTargetActions + 124
    frame #11: 0x000000018f15ce38 UIKit`_UIGestureRecognizerSendActions + 320
    frame #12: 0x000000018eff9740 UIKit`-[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 764
    frame #13: 0x000000018f558bd4 UIKit`_UIGestureEnvironmentUpdate + 1096
    frame #14: 0x000000018eff34d8 UIKit`-[UIGestureEnvironment _deliverEvent:toGestureRecognizers:usingBlock:] + 404
    frame #15: 0x000000018eff3010 UIKit`-[UIGestureEnvironment _updateGesturesForEvent:window:] + 276
    frame #16: 0x000000018eff2874 UIKit`-[UIWindow sendEvent:] + 3132
    frame #17: 0x000000018eff11d0 UIKit`-[UIApplication sendEvent:] + 340
    frame #18: 0x000000018f7d2d1c UIKit`__dispatchPreprocessedEventFromEventQueue + 2340
    frame #19: 0x000000018f7d52c8 UIKit`__handleEventQueueInternal + 4744
    frame #20: 0x000000018f7ce368 UIKit`__handleHIDEventFetcherDrain + 152
    frame #21: 0x00000001851b7404 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
    frame #22: 0x00000001851b6c2c CoreFoundation`__CFRunLoopDoSources0 + 276
    frame #23: 0x00000001851b479c CoreFoundation`__CFRunLoopRun + 1204
    frame #24: 0x00000001850d4da8 CoreFoundation`CFRunLoopRunSpecific + 552
    frame #25: 0x00000001870b9020 GraphicsServices`GSEventRunModal + 100
    frame #26: 0x000000018f0f1758 UIKit`UIApplicationMain + 236

The backtrace for the second one is:

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 4.1
  * frame #0: 0x000000018f006130 UIKit`-[UIViewController dismissViewControllerAnimated:completion:]
    frame #1: 0x000000018f41e1a4 UIKit`__103-[UIAlertController _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:dismissCompletion:]_block_invoke.465 + 248
    frame #2: 0x000000018f005fb4 UIKit`-[UIAlertController _performAction:invokeActionBlock:dismissAndPerformActionIfNotAlreadyPerformed:] + 124
    frame #3: 0x000000018f005b94 UIKit`-[UIAlertController _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:dismissCompletion:] + 824
    frame #4: 0x000000018f005848 UIKit`-[UIAlertController _dismissWithAction:dismissCompletion:] + 68
    frame #5: 0x000000018f0056ec UIKit`-[_UIAlertControllerView interfaceAction:invokeActionHandler:completion:] + 256
    frame #6: 0x000000018f005588 UIKit`-[UIInterfaceActionGroupView interfaceAction:invokeActionHandler:completion:] + 120
    frame #7: 0x000000018f005490 UIKit`-[UIInterfaceAction _invokeHandlerWithCompletionBlock:] + 168
    frame #8: 0x000000018efff2d8 UIKit`-[UIInterfaceActionSelectionTrackingController _handleActionSelectionGestureRecognizer:] + 864
    frame #9: 0x000000018effa6e8 UIKit`-[UIGestureRecognizerTarget _sendActionWithGestureRecognizer:] + 64
    frame #10: 0x000000018f5673b4 UIKit`_UIGestureRecognizerSendTargetActions + 124
    frame #11: 0x000000018f15ce38 UIKit`_UIGestureRecognizerSendActions + 320
    frame #12: 0x000000018eff9740 UIKit`-[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 764
    frame #13: 0x000000018f558bd4 UIKit`_UIGestureEnvironmentUpdate + 1096
    frame #14: 0x000000018eff34d8 UIKit`-[UIGestureEnvironment _deliverEvent:toGestureRecognizers:usingBlock:] + 404
    frame #15: 0x000000018eff3010 UIKit`-[UIGestureEnvironment _updateGesturesForEvent:window:] + 276
    frame #16: 0x000000018eff2874 UIKit`-[UIWindow sendEvent:] + 3132
    frame #17: 0x000000018eff11d0 UIKit`-[UIApplication sendEvent:] + 340
    frame #18: 0x000000018f7d2d1c UIKit`__dispatchPreprocessedEventFromEventQueue + 2340
    frame #19: 0x000000018f7d52c8 UIKit`__handleEventQueueInternal + 4744
    frame #20: 0x000000018f7ce368 UIKit`__handleHIDEventFetcherDrain + 152
    frame #21: 0x00000001851b7404 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
    frame #22: 0x00000001851b6c2c CoreFoundation`__CFRunLoopDoSources0 + 276
    frame #23: 0x00000001851b479c CoreFoundation`__CFRunLoopRun + 1204
    frame #24: 0x00000001850d4da8 CoreFoundation`CFRunLoopRunSpecific + 552
    frame #25: 0x00000001870b9020 GraphicsServices`GSEventRunModal + 100
    frame #26: 0x000000018f0f1758 UIKit`UIApplicationMain + 236

When the attached demo app launches, there's a single button labeled "present". Tap this button and then follow the steps described above to reproduce. After tapping "cancel", the initial view controller with the "present" button reappears.
Comment 1 Tom Harrington 2018-07-23 14:44:35 PDT 
Sorry, I pasted the same backtrace twice. The second one should be as follows.

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 4.1
  * frame #0: 0x000000018f006130 UIKit`-[UIViewController dismissViewControllerAnimated:completion:]
    frame #1: 0x0000000194eb2bd8 WebKit`-[WKActionSheet doneWithSheet:] + 56
    frame #2: 0x0000000194eb62a8 WebKit`-[WKActionSheetAssistant cleanupSheet] + 128
    frame #3: 0x000000018f006058 UIKit`-[UIAlertController _invokeHandlersForAction:] + 108
    frame #4: 0x000000018f41dffc UIKit`__103-[UIAlertController _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:dismissCompletion:]_block_invoke.461 + 28
    frame #5: 0x000000018f012364 UIKit`-[UIPresentationController transitionDidFinish:] + 1320
    frame #6: 0x000000018f2a3c88 UIKit`__56-[UIPresentationController runTransitionForCurrentState]_block_invoke.436 + 188
    frame #7: 0x000000018ee15b88 UIKit`-[_UIViewControllerTransitionContext completeTransition:] + 116
    frame #8: 0x000000018ee15730 UIKit`-[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] + 760
    frame #9: 0x000000018ee150b8 UIKit`-[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 312
    frame #10: 0x000000018eefefcc UIKit`-[UIViewAnimationState animationDidStop:finished:] + 296
    frame #11: 0x000000018eeff06c UIKit`-[UIViewAnimationState animationDidStop:finished:] + 456
    frame #12: 0x00000001893a5504 QuartzCore`CA::Layer::run_animation_callbacks(void*) + 284
    frame #13: 0x000000010520d19c libdispatch.dylib`_dispatch_client_callout + 16
    frame #14: 0x0000000105211d2c libdispatch.dylib`_dispatch_main_queue_callback_4CF + 1180
    frame #15: 0x00000001851b7070 CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
    frame #16: 0x00000001851b4bc8 CoreFoundation`__CFRunLoopRun + 2272
    frame #17: 0x00000001850d4da8 CoreFoundation`CFRunLoopRunSpecific + 552
    frame #18: 0x00000001870b9020 GraphicsServices`GSEventRunModal + 100
    frame #19: 0x000000018f0f1758 UIKit`UIApplicationMain + 236
Comment 2 Wenson Hsieh 2018-07-27 10:27:05 PDT 

*** This bug has been marked as a duplicate of bug 183549 ***
Comment 3 Wenson Hsieh 2018-07-27 10:32:03 PDT 
(In reply to Tom Harrington from comment #1)
> Sorry, I pasted the same backtrace twice. The second one should be as
> follows.
> 
> (lldb) bt
> * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 4.1
>   * frame #0: 0x000000018f006130 UIKit`-[UIViewController
> dismissViewControllerAnimated:completion:]
>     frame #1: 0x0000000194eb2bd8 WebKit`-[WKActionSheet doneWithSheet:] + 56
>     frame #2: 0x0000000194eb62a8 WebKit`-[WKActionSheetAssistant
> cleanupSheet] + 128
>     frame #3: 0x000000018f006058 UIKit`-[UIAlertController
> _invokeHandlersForAction:] + 108
>     frame #4: 0x000000018f41dffc UIKit`__103-[UIAlertController
> _dismissAnimated:triggeringAction:triggeredByPopoverDimmingView:
> dismissCompletion:]_block_invoke.461 + 28
>     frame #5: 0x000000018f012364 UIKit`-[UIPresentationController
> transitionDidFinish:] + 1320
>     frame #6: 0x000000018f2a3c88 UIKit`__56-[UIPresentationController
> runTransitionForCurrentState]_block_invoke.436 + 188
>     frame #7: 0x000000018ee15b88 UIKit`-[_UIViewControllerTransitionContext
> completeTransition:] + 116
>     frame #8: 0x000000018ee15730 UIKit`-[UIViewAnimationBlockDelegate
> _didEndBlockAnimation:finished:context:] + 760
>     frame #9: 0x000000018ee150b8 UIKit`-[UIViewAnimationState
> sendDelegateAnimationDidStop:finished:] + 312
>     frame #10: 0x000000018eefefcc UIKit`-[UIViewAnimationState
> animationDidStop:finished:] + 296
>     frame #11: 0x000000018eeff06c UIKit`-[UIViewAnimationState
> animationDidStop:finished:] + 456
>     frame #12: 0x00000001893a5504
> QuartzCore`CA::Layer::run_animation_callbacks(void*) + 284
>     frame #13: 0x000000010520d19c libdispatch.dylib`_dispatch_client_callout
> + 16
>     frame #14: 0x0000000105211d2c
> libdispatch.dylib`_dispatch_main_queue_callback_4CF + 1180
>     frame #15: 0x00000001851b7070
> CoreFoundation`__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 12
>     frame #16: 0x00000001851b4bc8 CoreFoundation`__CFRunLoopRun + 2272
>     frame #17: 0x00000001850d4da8 CoreFoundation`CFRunLoopRunSpecific + 552
>     frame #18: 0x00000001870b9020 GraphicsServices`GSEventRunModal + 100
>     frame #19: 0x000000018f0f1758 UIKit`UIApplicationMain + 236

Thanks for the information and test app, Tom!

I believe I've fixed this in <https://bugs.webkit.org/show_bug.cgi?id=183549>, which first went into iOS 12. I installed the test app (DismissDemo) on my build of iOS 12, and could not reproduce; could you verify on any beta version of iOS 12?