HHH-17795 fix an NPE and add a test for 'on conflict on constraint'

Author: gavinking

hibernate-core/src/main/antlr/org/hibernate/grammars/hql/HqlParser.g4

@@ -110,13 +110,18 @@ values
 /**
  * a 'conflict' clause in an 'insert' statement
  */
-conflictClause: ON CONFLICT conflictTarget? conflictAction;
+conflictClause
+	: ON CONFLICT conflictTarget? DO conflictAction
+	;
+
 conflictTarget
 	: ON CONSTRAINT identifier
-	| LEFT_PAREN simplePath (COMMA simplePath)* RIGHT_PAREN;
+	| LEFT_PAREN simplePath (COMMA simplePath)* RIGHT_PAREN
+	;
+
 conflictAction
-	: DO NOTHING
-	| DO UPDATE setClause whereClause?
+	: NOTHING
+	| UPDATE setClause whereClause?
 	;
 
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

hibernate-core/src/main/java/org/hibernate/boot/model/internal/AnnotationBinder.java

@@ -45,7 +45,6 @@
 import org.hibernate.boot.model.IdentifierGeneratorDefinition;
 import org.hibernate.boot.model.convert.spi.ConverterDescriptor;
 import org.hibernate.boot.model.convert.spi.RegisteredConversion;
-import org.hibernate.boot.registry.StandardServiceRegistry;
 import org.hibernate.boot.registry.classloading.spi.ClassLoaderService;
 import org.hibernate.boot.spi.BootstrapContext;
 import org.hibernate.boot.spi.InFlightMetadataCollector;

hibernate-core/src/main/java/org/hibernate/query/sqm/tree/insert/SqmConflictClause.java

@@ -70,7 +70,7 @@ public SqmRoot<T> getExcludedRoot() {
 
 	@Override
 	public SqmConflictClause<T> conflictOnConstraint(@Nullable String constraintName) {
-		if ( !constraintPaths.isEmpty() ) {
+		if ( constraintPaths != null && !constraintPaths.isEmpty() ) {
 			throw new IllegalStateException( "Constraint paths were already set: " + constraintPaths );
 		}
 		this.constraintName = constraintName;

hibernate-core/src/test/java/org/hibernate/orm/test/query/hql/InsertConflictOnConstraintTest.java

@@ -0,0 +1,38 @@
+package org.hibernate.orm.test.query.hql;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import jakarta.persistence.UniqueConstraint;
+import org.hibernate.dialect.PostgreSQLDialect;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.RequiresDialect;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@SessionFactory
+@DomainModel(annotatedClasses = InsertConflictOnConstraintTest.Constrained.class)
+@RequiresDialect(PostgreSQLDialect.class)
+public class InsertConflictOnConstraintTest {
+	@Test void test(SessionFactoryScope scope) {
+		scope.inTransaction( s -> s.persist(new Constrained()));
+		scope.inTransaction( s -> s.createMutationQuery("insert into Constrained(id, name, count) values (4,'Gavin',69) on conflict on constraint constrained_count_name_key do update set count = 96").executeUpdate());
+		scope.inSession( s -> assertEquals(96, s.createSelectionQuery("select count from Constrained", int.class).getSingleResult()));
+
+	}
+
+	@Entity(name = "Constrained")
+	@Table(uniqueConstraints = @UniqueConstraint(columnNames = {"count","name"}))
+	static class Constrained {
+		@Id
+		@GeneratedValue
+		long id;
+		String name = "Gavin";
+		int count = 69;
+	}
+
+}