Use fields directly for simplicity

h2/src/main/org/h2/command/ddl/AlterTableAlterColumn.java

@@ -570,9 +570,8 @@ public class AlterTableAlterColumn extends CommandWithColumns {
 
     @Override
     public void addColumn(Column column) {
-        ArrayList<Column> columnsToAdd = this.columnsToAdd;
         if (columnsToAdd == null) {
-            this.columnsToAdd = columnsToAdd = New.arrayList();
+            columnsToAdd = New.arrayList();
         }
         columnsToAdd.add(column);
     }

h2/src/main/org/h2/command/ddl/CommandWithColumns.java

@@ -73,7 +73,6 @@ public abstract class CommandWithColumns extends SchemaCommand {
     }
 
     protected void createConstraints() {
-        ArrayList<DefineCommand> constraintCommands = this.constraintCommands;
         if (constraintCommands != null) {
             for (DefineCommand command : constraintCommands) {
                 command.setTransactional(transactional);
@@ -103,9 +102,8 @@ public abstract class CommandWithColumns extends SchemaCommand {
     }
 
     private ArrayList<DefineCommand> getConstraintCommands() {
-        ArrayList<DefineCommand> constraintCommands = this.constraintCommands;
         if (constraintCommands == null) {
-            this.constraintCommands = constraintCommands = New.arrayList();
+            constraintCommands = New.arrayList();
         }
         return constraintCommands;
     }