Calling of `Bridge.restoreInstanceState(this, savedInstanceState)` without checking `savedInstanceState != null` could cause accidental removal of saved sharedPreferences

The bridgeDelegate has the below functions

    void restoreInstanceState(@NonNull Object target, @Nullable Bundle state) {
        boolean isFirstRestoreCall = mIsFirstRestoreCall;
        mIsFirstRestoreCall = false;
        if (state == null) {
            if (isFirstRestoreCall) {
                mSharedPreferences.edit()
                        .clear()
                        .apply();
            }
            return;
        }
        // ... other codes
    }

With this, we are suppose to call the restoreInstanceState without checking the savedInstanceState to help clear the sharedPreference, as we assume this is the state where it doesn’t have state restoration needed.

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        Bridge.restoreInstanceState(this, savedInstanceState)
        // .... other codes
    }

However, there could be chance where isFirstRestoreCall is true, and savedInstanceState is also null, but it is actually in a restored state. This would cause accidental removal of all saved and needed sharedPreference

This issue is further describe in https://medium.com/@elye.project/handling-transactiontoolargeexception-with-livefront-bridge-a846459420bb, the Uses restoreInstanceState to help clear the data is called without StateRestoration section

[byencho]

@elye OK yeah I can understand the scenario you are talking about now. Thanks for clarifying that. As mentioned above, I wasn’t really expecting people to “selectively” use Bridge in just a few Activity / Fragment; the thought was that all screens would use Bridge by just placing the calls in a base class. Because there is no requirement to do so, though, I can see how this issue can pop up for some people unexpectedly and is something I should fix.

Fortunately there is a pretty easy fix for this : rather than doing the isFirstRestoreCall check inside restoreInstanceState (which might not be called for every Activity / Fragment in the scenario you’ve described) I can just do the check inside the ActivityLifecycleCallbacks.onActivityCreated callback, which will be triggered for every Activity (not just those that use Bridge). So I think this is a fix I can incorporate soon.

Thanks for helping find this issue!

[byencho]

@elye I’m going to close this issue now. If you still seem to have problems, feel free to re-open it.