Automatically clear data breaks app on change app

[rwdj]

Steps to reproduce:

1. Turn on Automatically clear data. Any settings. I've tried multiple configs, but I specifically had "Clear Tabs and Data" and "App Exit, Inactive for 1 hour".
2. Change app. Don't bother navigating to a web page. It's not necessary.
3. Change back. The app is not functional. Address bar is usable, but attempts to navigate the web fail. All buttons stop functioning; although, the UI continues to work, meaning buttons blink as they should when pressed, but no menus appear.

PS: I'm loving this app.

[bwaresiak]

@rwdj sorry to hear it doesn't work for you.

I've tried to reproduce the problem but couldn't. Shall I wait for Auto Clear to happen (e.g. 1hour) between steps #2 and #3 or is just switching the app enough for the problem to manifest?

Also can you share what iOS version, device and DDG app version you are using?

Thank you!

[rwdj]

I just turned the feature back on and it stopped happening. To my knowledge, I haven’t updated since, so I’m not sure what happened.

Since it’s no longer happening, I’ll tentatively close this issue. But I’ll keep an eye on it and reopen if it happens again and try to identify what changed.

Just in case it comes back up, here are the answers to your questions:

No waiting was needed. I could just flip to another app and back and it’d seize.

This was my info at TOI. It was in my original post, but I edited it out:

DuckDuckGo iOS Version: 7.61.3.0
Device: iPhone 11 Pro
iOS: 14.2

[rwdj]

It's happening again. Can't think of anything I've done different. If I disable Automatically Clear Data, it works fine. If I enable Automatically Clear Data, it does this usually:

Note that my Favorites are gone and the 1 tab indicator is gone. If I close the app and reopen, everything is fine.

[rwdj]

@bwaresiak I can't reopen the issue and am not sure if you got pinged, so here's a ping.
Merry Christmas Eve!
I'll just disable auto clear for now.
I'm a developer too (not iOS developer) and have a MacBook that I'm not afraid to use to get any diagnostic data you want from me.

[bwaresiak]

@rwdj thanks! Hope you had great Christmas. :)

Have few things in mind:

I. Are there any DDG-related crashlogs on your device?
II. When this happens, is there any indication of a deadlock? E.g.:

1. Open the app - see UI is stuck.
2. Background the app again.
3. Wait 10 seconds.
4. Reopen the app - if you see launch screen and it is starting "from scratch" that could mean we have a deadlock and watchdog just killed our app (as it couldn't process background event on time).

III. I did enable this option on my device but so far I haven't seen any problems. Can you share if you have any of these settings enabled:

• Auth Lock.
• Keyboard options for app launch / new tab.
• Fireproofing (and if you have any websites fireproofed).
• GPC.

Does this happen when you open our app by tapping its icon, or maybe when navigating from links (default browser/share) or from widget (new search/favorite)?

[rwdj]

It's stopped happening again. Waiting to see when it happens again.
I. I’ve looked through crashlogs and didn’t see any entries for DuckDuckGo.
II. I’ll try that procedure next time it starts happening.
III.

• Application Lock: default - no
• Keyboard Options:
  • New Tab: default - yes
  • App Launch: default - no
• Fireproofed Sites: 4
• GPC: default - yes

Since I’ve made my report and it’s started/stopped/started working, I haven’t changed any settings except maybe adding bookmarks, but I doubt that’s it.

DDG is my default browser and I don’t use the widget. I tried opening a url in an email (both with and without DDG open in background) and wasn’t able to trigger it. However, I’d like to point out part of my original procedure was reopening DDG before and after. That means no webpages were open at the time including webpages opened from other apps. That said, I'm having trouble reproducing it again.

Now that it’s working, I notice the locked-up state resembles what the app looks like when the active app isn’t DDG (by viewing from the background app switcher). Possibly DDG wasn’t recognizing it became the focused/active app?

[bwaresiak]

@rwdj I've been trying to reproduce this issue over the Christmas period but had no success so far.

For now my two ideas are:

• Deadlock: in such case scenario I've wrote above (backgrounding the app) should make watchdog kill the app.
• Background State overlay not being removed: maybe something is messing up UIWindow state and overlay is not properly removed.

I could try to hack something for the latter issue (trying to tweak windowLevel / hidden properties on the UIWindow), but first I'd like to first get confirmation from you whether it may be related to the deadlock idea or not.

[rwdj]

I still can't reproduce it anymore. Great for me! Not so great overall.

It sounds more like the overlay, because I don't think a killed app would act the way it did.

If watchdog killed the app, would the app be interactable? When locked-up, the app buttons and even the address bar were responsive; they just didn't do anything functional: broken buttons. They made GUI action indications (changing color) without actually doing the intended function. I was even able to type things into the url.
I presume that's not what a killed app does. It seemed more like it was an overlay.

[bwaresiak]

@rwdj thank you, that indeed looks like problem with the overlay. Glad to hear this seem to be a rare problem! Nonetheless, I'll try to tackle it this week.

[bwaresiak]

@rwdj I've made a PR #804 aimed at tackling this: get a signal if this happens (to understand impact) and then try to recover. Ideally we will like to fix this, but first we need to be able to tell if our tweaks are going to have any effect.

[rwdj]

Well. Huh. Today, it's happening sporadically without any noticeable pattern. Sometimes it does. Sometimes it doesn't. This is very different from before where it would happen every time or not at all.

[rwdj]

Scratch that. Reproducible. For now. I also took a video. But I don't think it'll help. I think you've also gotten a handle on it.

[bwaresiak]

@rwdj I'm going to release new version early next week, let's see if that changes anything.

[bwaresiak]

@rwdj Could you get 7.61.8 from AppStore and see if the issue happens, that it is recovering once you tap on any button?

[rwdj]

I'll do that and let you know the next time it happens! In the meantime, I just re-enabled automatically clear data and it's not happening again. Last time it took nearly long over a week to start happening again.

[rwdj]

I still haven't seen it happen again. I know I'd recognize it if it did by showing the overlay and I'd need to click a button to fix it, but it just hasn't happened.

[bwaresiak]

@rwdj Thank you for checking in :) If you manage to see it please let us know. In the meantime we've got some signal about it and I've got an idea for a permanent fix - will try to address it this week.

[rwdj]

I know I've seen the temporary fix. Not sure when the last time was or if it's been properly fixed. At the very least, it's fixed from a user perspective.

[rwdj]

Ah. Literally just saw it happen again. But your temporary fix saves the day.

[brindy]

I was trying to reproduce this recently and was unable to, is it still an issue for your @rwdj ?

[rwdj]

Nope. Feel free to close.

I only left this open for tracking purposes for y'all figuring out the root cause, but I haven't seen the temporary fix triggered in a good while.

[brindy]

Great, thanks!