[#1803] Fix NPE caused by wrong order by expression during criteria builder copying

CHANGELOG.md

@@ -14,6 +14,7 @@ Changes that happened in releases
 * Fix dropping of embeddable group by expression when nested property has same name as parent property
 * Fix SQL generation for lateral subqueries when correlated path has `@Where` predicate
 * Fix `ConcurrentModificationException` during metamodel determination for special Hibernate Envers mappings
+* Fix NPE caused by wrong order by expression during criteria builder copying 
 
 ### Backwards-incompatible changes
 

build.sh

@@ -15,9 +15,9 @@ export MAVEN_OPTS="$MAVEN_OPTS -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli
 # Increase retry count and reduce TTL for connections: https://github.com/actions/virtual-environments/issues/1499#issuecomment-718396233
 export MAVEN_OPTS="$MAVEN_OPTS -Dmaven.wagon.httpconnectionManager.ttlSeconds=25 -Dmaven.wagon.http.retryHandler.count=3"
 if [[ "$JDK" != "" ]]; then
-  export MAVEN_OPTS="-Xmx1280m -XX:MaxMetaspaceSize=512m $MAVEN_OPTS"
+  export MAVEN_OPTS="-Xmx1536m -XX:MaxMetaspaceSize=512m $MAVEN_OPTS"
 else
-  export MAVEN_OPTS="-Xmx1280m -XX:MaxPermSize=512m $MAVEN_OPTS"
+  export MAVEN_OPTS="-Xmx1536m -XX:MaxPermSize=512m $MAVEN_OPTS"
 fi
 
 $DIR/mvnw -version

core/impl/src/main/java/com/blazebit/persistence/impl/ConstantifiedJoinNodeAttributeCollector.java

@@ -113,6 +113,10 @@ public void collectConstantifiedJoinNodeAttributes(CompoundPredicate rootPredica
         rootPredicate.accept(this);
     }
 
+    public AliasManager getAliasManager() {
+        return aliasManager;
+    }
+
     public Map<Object, Map<String, Boolean>> getConstantifiedJoinNodeAttributes() {
         return constantifiedJoinNodeAttributes;
     }

core/impl/src/main/java/com/blazebit/persistence/impl/ExpressionUtils.java

@@ -247,6 +247,17 @@ private static boolean isNullable(EntityMetamodel metamodel, ConstantifiedJoinNo
                 return true;
             }
             int size = expressions.size();
+            if (rootTypes == null) {
+                if (size == 1 && constantifiedJoinNodeAttributeCollector != null) {
+                    // In this case, the expression could be an alias referring to a non-path select item
+                    AliasInfo aliasInfo = constantifiedJoinNodeAttributeCollector.getAliasManager().getAliasInfo(((PropertyExpression) expression).getProperty());
+                    if (aliasInfo instanceof SelectInfo) {
+                        return isNullable(metamodel, constantifiedJoinNodeAttributeCollector, ((SelectInfo) aliasInfo).getExpression());
+                    }
+                }
+                // Not sure if this case is possible, but let's play defensive and return that this is nullable
+                return true;
+            }
             Type<?> baseType = rootTypes.get(((PropertyExpression) expression).getProperty());
             int i = 0;
             if (baseType != null) {

core/impl/src/main/java/com/blazebit/persistence/impl/OrderByManager.java

@@ -104,12 +104,12 @@ String[] applyFrom(OrderByManager orderByManager, Map<String, Integer> identifie
                     if (selectInfo.getExpression() instanceof PathExpression) {
                         expression = copiedSelectExpression;
                     } else {
-                        String alias = aliasManager.generateRootAlias("_generated_alias");
-                        selectManager.select(copiedSelectExpression, alias);
+                        String alias = aliasManager.generateRootAlias("bp_generated_alias");
                         List<Expression> args = new ArrayList<>(2);
-                        args.add(new PathExpression(new PropertyExpression(alias)));
+                        args.add(copiedSelectExpression);
                         args.add(new StringLiteral(alias));
-                        expression = new FunctionExpression(AliasFunction.FUNCTION_NAME, args);
+                        selectManager.select(new FunctionExpression(AliasFunction.FUNCTION_NAME, args), alias);
+                        expression = new PathExpression(new PropertyExpression(alias));
                     }
                 }
             } else {

entity-view/testsuite/src/test/java/com/blazebit/persistence/view/testsuite/pagination/PaginationTest.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2014 - 2023 Blazebit.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.blazebit.persistence.view.testsuite.pagination;
+
+import com.blazebit.persistence.PaginatedCriteriaBuilder;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoDatanucleus;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoEclipselink;
+import com.blazebit.persistence.testsuite.base.jpa.category.NoOpenJPA;
+import com.blazebit.persistence.testsuite.entity.Document;
+import com.blazebit.persistence.testsuite.entity.Person;
+import com.blazebit.persistence.testsuite.tx.TxVoidWork;
+import com.blazebit.persistence.view.EntityView;
+import com.blazebit.persistence.view.EntityViewManager;
+import com.blazebit.persistence.view.EntityViewSetting;
+import com.blazebit.persistence.view.FetchStrategy;
+import com.blazebit.persistence.view.Mapping;
+import com.blazebit.persistence.view.Sorters;
+import com.blazebit.persistence.view.testsuite.AbstractEntityViewTest;
+import com.blazebit.persistence.view.testsuite.basic.model.IdHolderView;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import javax.persistence.EntityManager;
+import java.util.List;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ *
+ * @author Christian Beikov
+ * @since 1.6.10
+ */
+public class PaginationTest extends AbstractEntityViewTest {
+
+    protected EntityViewManager evm;
+
+    @Before
+    public void initEvm() {
+        evm = build(DocumentViewInterface.class, PersonIdView.class);
+    }
+
+    @Override
+    public void setUpOnce() {
+        cleanDatabase();
+        transactional(new TxVoidWork() {
+            @Override
+            public void work(EntityManager em) {
+                doc1 = new Document("doc1");
+                Person o1 = new Person("pers1");
+
+                doc1.setAge(10);
+                doc1.setOwner(o1);
+
+                doc1.getContacts().put(1, o1);
+                doc1.getContacts2().put(2, o1);
+
+                em.persist(o1);
+                em.persist(doc1);
+                em.persist(new Document("doc2", o1));
+            }
+        });
+    }
+
+    @Before
+    public void setUp() {
+        doc1 = cbf.create(em, Document.class).where("name").eq("doc1").getSingleResult();
+    }
+
+    private Document doc1;
+
+    @Test
+    @Category({ NoEclipselink.class, NoDatanucleus.class, NoOpenJPA.class })
+    // TODO: report eclipselink does not support subqueries in functions
+    public void testPagination() {
+        EntityViewSetting<DocumentViewInterface, PaginatedCriteriaBuilder<DocumentViewInterface>> settings = EntityViewSetting.create(DocumentViewInterface.class, 0, 1)
+            .withAttributeSorter("number", Sorters.ascending())
+            .withAttributeSorter("id", Sorters.ascending());
+        List<DocumentViewInterface> page = evm.applySetting(settings, cbf.create(em, Document.class)).getResultList();
+        assertEquals(1, page.size());
+    }
+
+    @EntityView(Document.class)
+    public interface DocumentViewInterface extends IdHolderView<Long> {
+
+        public String getName();
+
+        @Mapping("COALESCE(FUNCTION('cast_long', idx), id)")
+        public Long getNumber();
+
+        @Mapping(fetch = FetchStrategy.SUBSELECT)
+        Set<PersonIdView> getContacts();
+
+    }
+    @EntityView(Person.class)
+    public interface PersonIdView extends IdHolderView<Long> {
+
+    }
+}