HHH-19596 Additional fix for 6.6 backport

Author: cigaly

hibernate-core/src/main/java/org/hibernate/dialect/AbstractPostgreSQLStructJdbcType.java

@@ -1156,6 +1156,9 @@ private static String unescape(CharSequence string, int start, int end) {
 	@Override
 	public Object createJdbcValue(Object domainValue, WrapperOptions options) throws SQLException {
 		assert embeddableMappingType != null;
+		if (domainValue == null) {
+			return null;
+		}
 		final StringBuilder sb = new StringBuilder();
 		serializeStructTo( new PostgreSQLAppender( sb ), domainValue, options );
 		return sb.toString();

hibernate-core/src/main/java/org/hibernate/dialect/StructHelper.java

@@ -105,6 +105,9 @@ public static Object[] getJdbcValues(
 			WrapperOptions options) throws SQLException {
 		final int jdbcValueCount = embeddableMappingType.getJdbcValueCount();
 		final int valueCount = jdbcValueCount + ( embeddableMappingType.isPolymorphic() ? 1 : 0 );
+		if (domainValue == null) {
+			return null;
+		}
 		final Object[] values = embeddableMappingType.getValues( domainValue );
 		final Object[] jdbcValues;
 		if ( valueCount != values.length || orderMapping != null ) {

hibernate-core/src/main/java/org/hibernate/dialect/StructJdbcType.java

@@ -141,11 +141,13 @@ public Object createJdbcValue(Object domainValue, WrapperOptions options) throws
 				domainValue,
 				options
 		);
-		return options.getSession()
+		return jdbcValues == null
+				? null
+				: options.getSession()
 				.getJdbcCoordinator()
 				.getLogicalConnection()
 				.getPhysicalConnection()
-				.createStruct( typeName, jdbcValues );
+				.createStruct(typeName, jdbcValues);
 	}
 
 	@Override