IssueTracker

Component used: androidx.preference:preference

Version used: 1.2.0

Devices/Android versions reproduced on: generic tablets / Android 9

This is regarding PreferenceHeaderFragmentCompat. The API documentation states (sic):

By default, the initial state fragment for the detail pane is set to the associated fragment that first found in preference headers.

This is false and only works as stated if the first element in the PreferenceScreen is an instance of Preference and not an instance of PreferenceCategory.

Reviewing the source, it becomes clear that the code assumes the preference count only takes into account top level Preferences, and does not include the ones under a PreferenceCategory.

        for (index in 0 until headerFragment.preferenceScreen.preferenceCount) {
            val header = headerFragment.preferenceScreen.getPreference(index)
            if (header.fragment == null) {
                continue
            }
            ...

The code should recurse if the object returned by getPreference() is an instance of PreferenceGroup.

Please fix.