fix: handle nullable nextPage behavior when searching albums #12401 (#12408)

* fix: handle nullable nextPage behavior when searching albums #12401

* feat: add nullable annotation to newPage attribute in SearchFragment

* Updated more usages of InfoItemsPage#getNextPage. Nullability is already handled in these areas so no other changes needed

---------

Co-authored-by: Siddhesh Naik <[email protected]>

Author: koukibadr

app/src/main/java/org/schabi/newpipe/fragments/list/BaseListInfoFragment.java

@@ -8,6 +8,7 @@
 import android.view.View;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import com.evernote.android.state.State;
 
@@ -42,6 +43,7 @@ public abstract class BaseListInfoFragment<I extends InfoItem, L extends ListInf
 
     private final UserAction errorUserAction;
     protected L currentInfo;
+    @Nullable
     protected Page currentNextPage;
     protected Disposable currentWorker;
 

app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java

@@ -144,6 +144,7 @@ public class SearchFragment extends BaseListFragment<SearchInfo, ListExtractor.I
 
     private final SparseArrayCompat<String> menuItemToFilterName = new SparseArrayCompat<>();
     private StreamingService service;
+    @Nullable
     private Page nextPage;
     private boolean showLocalSuggestions = true;
     private boolean showRemoteSuggestions = true;
@@ -1090,7 +1091,7 @@ public void handleNextItems(final ListExtractor.InfoItemsPage<?> result) {
         infoListAdapter.addInfoItemList(result.getItems());
         nextPage = result.getNextPage();
 
-        if (!result.getErrors().isEmpty()) {
+        if (!result.getErrors().isEmpty() && nextPage != null) {
             showSnackBarError(new ErrorInfo(result.getErrors(), UserAction.SEARCHED,
                     "\"" + searchString + "\" → pageUrl: " + nextPage.getUrl() + ", "
                             + "pageIds: " + nextPage.getIds() + ", "

app/src/main/java/org/schabi/newpipe/player/playqueue/AbstractInfoPlayQueue.java

@@ -3,6 +3,7 @@
 import android.util.Log;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import org.schabi.newpipe.extractor.InfoItem;
 import org.schabi.newpipe.extractor.ListExtractor;
@@ -23,6 +24,7 @@ abstract class AbstractInfoPlayQueue<T extends ListInfo<? extends InfoItem>>
 
     final int serviceId;
     final String baseUrl;
+    @Nullable
     Page nextPage;
 
     private transient Disposable fetchReactor;