fix(pm): preserve message WebView state across recreation (#691)

[jim-daf]

Closes #691.

Reopening the PM view after popping back from the settings activity (and on configuration changes in general) shows a blank message body. The fragment uses setRetainInstance(true) for the wrapper but the embedded AwfulWebView is rebuilt and its state is not preserved.

This change persists the WebView in onSaveInstanceState, restores it in onCreateView, and skips the syncPM() refetch when there is a snapshot to restore. The blank screen goes away and the existing first-load path is unchanged.

@Override
public void onSaveInstanceState(@androidx.annotation.NonNull Bundle outState) {
    super.onSaveInstanceState(outState);
    if (messageWebView != null) {
        messageWebView.saveState(outState);
    }
}

if (aSavedState != null) {
    messageWebView.restoreState(aSavedState);
}

if (pmId <= 0) {
    messageWebView.setVisibility(GONE);
} else if (aSavedState == null) {
    syncPM();
}

[Copilot]

Pull request overview

Fixes the PM detail view showing a blank message body after returning from Settings or other fragment recreation events by persisting/restoring the embedded AwfulWebView state and avoiding an unnecessary refetch when a snapshot is available.

Changes:

• Save the message AwfulWebView state in onSaveInstanceState.
• Restore the saved AwfulWebView state in onCreateView.
• Skip syncPM() when restoring from saved state.

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[Copilot]

WebView#saveState writes keys directly into the provided Bundle; to avoid accidental key collisions with fragment/view state and to make it possible to detect whether anything was actually saved, consider saving into a dedicated nested Bundle (e.g., outState.putBundle(...)) and/or tracking saveState’s return value.

[Copilot]

restoreState is being called after setContent(...) has already loaded the container HTML. Per WebView lifecycle expectations, restore is most reliable before any load; consider restoring first (or skipping setContent entirely when restoring) to avoid overwriting/restoring inconsistently or causing an extra blank load/flicker.

Suggested change

	messageWebView.setContent(AwfulHtmlPage.getContainerHtml(mPrefs, null, false));
	// Issue #691: restore the saved WebView snapshot when the
	// fragment is recreated so the message body does not come back
	// blank after popping back from the settings activity.
	if (aSavedState != null) {
	messageWebView.restoreState(aSavedState);
	// Issue #691: restore the saved WebView snapshot when the
	// fragment is recreated so the message body does not come back
	// blank after popping back from the settings activity.
	if (aSavedState != null) {
	messageWebView.restoreState(aSavedState);
	} else {
	messageWebView.setContent(AwfulHtmlPage.getContainerHtml(mPrefs, null, false));

[Copilot]

Using aSavedState == null as the only gate for syncPM() can skip the network fetch even when no WebView state was actually restored (e.g., saveState returned null / state missing in the Bundle). Consider gating on “restore succeeded” (e.g., restoreState return value != null, or presence of a dedicated saved Bundle) rather than just Bundle non-nullness.

[Copilot]

Style consistency: elsewhere in the codebase @NonNull is imported (import androidx.annotation.NonNull) rather than using the fully-qualified @androidx.annotation.NonNull in method signatures. Importing NonNull here would match the existing convention.