Fix DB update issue (#5016)

app/src/main/java/fr/free/nrw/commons/category/CategoryDao.java

@@ -93,9 +93,11 @@ List<CategoryItem> recentCategories(int limit) {
             // fixme add a limit on the original query instead of falling out of the loop?
             while (cursor != null && cursor.moveToNext()
                     && cursor.getPosition() < limit) {
-                items.add(new CategoryItem(fromCursor(cursor).getName(),
-                    fromCursor(cursor).getDescription(), fromCursor(cursor).getThumbnail(),
-                    false));
+                if (fromCursor(cursor).getName() != null ) {
+                    items.add(new CategoryItem(fromCursor(cursor).getName(),
+                        fromCursor(cursor).getDescription(), fromCursor(cursor).getThumbnail(),
+                        false));
+                }
             }
         } catch (RemoteException e) {
             throw new RuntimeException(e);
@@ -193,6 +195,13 @@ public static void onUpdate(SQLiteDatabase db, int from, int to) {
                 onUpdate(db, from, to);
                 return;
             }
+            if (from == 17) {
+                db.execSQL("ALTER TABLE categories ADD COLUMN description STRING;");
+                db.execSQL("ALTER TABLE categories ADD COLUMN thumbnail STRING;");
+                from++;
+                onUpdate(db, from, to);
+                return;
+            }
         }
     }
 }

app/src/main/java/fr/free/nrw/commons/category/CategoryItem.kt

@@ -4,8 +4,8 @@ import android.os.Parcelable
 import kotlinx.android.parcel.Parcelize
 
 @Parcelize
-data class CategoryItem(val name: String, val description: String,
-                        val thumbnail: String, var isSelected: Boolean) : Parcelable {
+data class CategoryItem(val name: String, val description: String?,
+                        val thumbnail: String?, var isSelected: Boolean) : Parcelable {
 
     override fun toString(): String {
         return "CategoryItem: '$name'"