Fix some JSON function rendering issues on HANA

Author: beikov

hibernate-core/src/main/java/org/hibernate/dialect/aggregate/HANAAggregateSupport.java

@@ -115,7 +115,7 @@ public String aggregateComponentCustomReadExpression(
 						if ( SqlTypes.isBinaryType( column.getJdbcMapping().getJdbcType().getDdlTypeCode() ) ) {
 							return template.replace(
 									placeholder,
-									"hextobin(json_value(" + parentPartExpression + columnExpression + "'))"
+									"hextobin(replace(json_value(" + parentPartExpression + columnExpression + "'),'-',''))"
 							);
 						}
 						// Fall-through intended

hibernate-core/src/main/java/org/hibernate/dialect/function/json/HANAJsonObjectAggFunction.java

@@ -71,19 +71,13 @@ protected void renderArgument(
 			sqlAppender.appendSql( " as nvarchar(" + Integer.MAX_VALUE + "))" );
 		}
 		else {
-			if ( nullBehavior != JsonNullBehavior.NULL ) {
-				sqlAppender.appendSql( "nullif(" );
-			}
 			sqlAppender.appendSql( "json_query((select " );
 			arg.accept( translator );
 			sqlAppender.appendSql( " V from sys.dummy for json('arraywrap'='no'" );
-			if ( nullBehavior != JsonNullBehavior.NULL ) {
+			if ( nullBehavior == JsonNullBehavior.NULL ) {
 				sqlAppender.appendSql( ",'omitnull'='no'" );
 			}
 			sqlAppender.appendSql( ") returns nvarchar(" + Integer.MAX_VALUE + ")),'$.V')" );
-			if ( nullBehavior != JsonNullBehavior.NULL ) {
-				sqlAppender.appendSql( ",'null')" );
-			}
 		}
 	}
 }