[MaterialDatePicker] Crash on SingleDateSelector

[green985]

Crashlytics show

Attempt to read from field 'java.lang.Long com.google.android.material.datepicker.SingleDateSelector.a' on a null object reference

#608
#590

Possible duplicated but in new version of material design library, this bug still not solved.
Used material design version = "1.3.0-beta01"

I changed my library version to "1.4.0-alpha02" but I believed on new release, this bug not solved.

Devices version Android 9-10-11.

Thanks your attention and thanks for all your works.

[drchen]

The crash looks not like a duplicate of #608 or #590.

Can you provide the complete stack trace of the crash?

[green985]

Fatal Exception: java.lang.NullPointerException: Attempt to read from field 'java.lang.Long com.google.android.material.datepicker.SingleDateSelector.a' on a null object reference
at com.google.android.material.datepicker.SingleDateSelector.getSelection(SingleDateSelector.java:1)
at com.google.android.material.datepicker.MaterialDatePicker.getSelection(MaterialDatePicker.java:1)
InputValidationExtKt.isBirthdayValid(InputValidationExtKt.java:35)
at android.view.View.performClick(View.java:7161)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:3)
at android.view.View.performClickInternal(View.java:7138)
at android.view.View.access$3500(View.java:811)
at android.view.View$PerformClick.run(View.java:27419)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:224)
at android.app.ActivityThread.main(ActivityThread.java:7520)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:539)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:950)

[drchen]

Can you show me what InputValidationExtKt.isBirthdayValid() is doing?

The crash can happen when InputValidationExtKt.isBirthdayValid() is called before MaterialDatePicker.onCreate() is called, which cause the NPE.

[green985]

fun TextInputLayout.isBirthdayValid(datePicker: MaterialDatePicker?): Boolean {

var text = this.editText?.text.toString()
if (text.isNullOrEmpty() || datePicker == null || datePicker.selection == null) {
    this.setHintWithError(R.string.birthdate_required, true)
    return false
}

try {
    val sdf = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
    val netDate = Date(datePicker.selection!!)
    sdf.format(netDate)
} catch (e: Exception) {
    this.setHintWithError(R.string.birthdate_required, true)
    return false
}
this.hint = resources.getString(R.string.birthday)
this.error = null
return true

}

[green985]

Actually isBirthdayValid called after close date picker dialog, this is a register operation fragment and after register button this control called.

[green985]

Thanks for your great work.
Have a nice day :)