Fix inconsistency between user interaction and database commit order when re-adding videos to the playlist

app/src/main/java/org/schabi/newpipe/fragments/detail/VideoDetailFragment.java

@@ -54,6 +54,7 @@ import androidx.appcompat.content.res.AppCompatResources;
 import androidx.appcompat.widget.Toolbar;
 import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import androidx.core.content.ContextCompat;
+import androidx.fragment.app.Fragment;
 import androidx.preference.PreferenceManager;
 
 import com.google.android.exoplayer2.PlaybackException;
@@ -89,6 +90,7 @@ import org.schabi.newpipe.fragments.list.videos.RelatedItemsFragment;
 import org.schabi.newpipe.ktx.AnimationType;
 import org.schabi.newpipe.local.dialog.PlaylistDialog;
 import org.schabi.newpipe.local.history.HistoryRecordManager;
+import org.schabi.newpipe.local.playlist.LocalPlaylistFragment;
 import org.schabi.newpipe.player.Player;
 import org.schabi.newpipe.player.PlayerService;
 import org.schabi.newpipe.player.PlayerType;
@@ -472,10 +474,21 @@ public final class VideoDetailFragment
 
         binding.detailControlsBackground.setOnClickListener(v -> openBackgroundPlayer(false));
         binding.detailControlsPopup.setOnClickListener(v -> openPopupPlayer(false));
-        binding.detailControlsPlaylistAppend.setOnClickListener(makeOnClickListener(info ->
+        binding.detailControlsPlaylistAppend.setOnClickListener(makeOnClickListener(info -> {
+            if (getFM() != null && currentInfo != null) {
+                final Fragment fragment = getParentFragmentManager().
+                        findFragmentById(R.id.fragment_holder);
+
+                // commit previous pending changes to database
+                if (fragment instanceof LocalPlaylistFragment) {
+                    ((LocalPlaylistFragment) fragment).commitChanges();
+                }
+
                 disposables.add(PlaylistDialog.createCorrespondingDialog(requireContext(),
                         List.of(new StreamEntity(info)),
-                        dialog -> dialog.show(getParentFragmentManager(), TAG)))));
+                        dialog -> dialog.show(getParentFragmentManager(), TAG)));
+            }
+        }));
         binding.detailControlsDownload.setOnClickListener(v -> {
             if (PermissionHelper.checkStoragePermissions(activity,
                     PermissionHelper.DOWNLOAD_DIALOG_REQUEST_CODE)) {

app/src/main/java/org/schabi/newpipe/local/playlist/LocalPlaylistFragment.java

@@ -158,6 +158,15 @@ public class LocalPlaylistFragment extends BaseLocalListFragment<List<PlaylistSt
         return headerBinding;
     }
 
+    // Commit changes immediately when the user turns to the player.
+    // Delete operations will be committed to ensure that the database
+    // is up to date when the user adds the just deleted stream by the player.
+    public void commitChanges() {
+        if (isModified != null && isModified.get()) {
+            saveImmediate();
+        }
+    }
+
     @Override
     protected void initListeners() {
         super.initListeners();