[GROOVY-8728] Verifier.addDefaultParameters erases metadata if run more than once

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.15, 2.5.1
• Fix Version/s: 2.5.2
• Assignee: Paul King
• Reporter: Eric Milles
• Created: 03/Aug/18 15:24
• Updated: 14/Aug/18 08:05
• Resolved: 06/Aug/18 14:24

Description

When processing sources with closure with parameter defaults, Verifier is wiping out the node metadata that contains the initial value expression.  At the end of addDefaultParameters(DefaultArgsAction action, MethodNode method), there is a for loop:

        for (Parameter parameter : parameters) {
            // GRECLIPSE add
            if (!parameter.hasInitialExpression()) continue;
            // GRECLIPSE end
            // remove default expression and store it as node metadata
            parameter.putNodeMetaData(Verifier.INITIAL_EXPRESSION, parameter.getInitialExpression());
            parameter.setInitialExpression(null);
        }

This loop currently moves the initial expression to node metadata. However, when this method runs a second time, it takes null from getInitialExpression and puts that as the new metadata value, even if the node already has been processed.

Adding a check hasInitialExpression solves this issue, making addDefaultParameters idempotent. This also prevent adding the metadata value in the first place for a parameter that never had a default value expression.