FM 2.3.12: NullPointerException in BlockAssignment.getCanonicalForm() when assign body is zero length

Hello all; I've just joined this list, so please let me know if this
isn't the correct place to be posting .

The following template gets an error in getCanonicalForm():

---Failing Template---
<#ftl>
<#assign x></#assign> 

---Test Program---
import java.io.IOException;
import freemarker.template.Configuration;
import freemarker.template.Template;

public class CanonicalTest {

    public static void main(String args[]) throws IOException {
        String filename = args[0];
        Configuration config = new Configuration();
        Template t = config.getTemplate(filename);
        System.out.print(t.getRootTreeNode().getCanonicalForm());
    }
}

---Execution Trace---
java -classpath
.\;c:/ds/svn1/docushare3/vendor/freemarker/freemarker.jar CanonicalTest
AssignFail.ftl
Exception in thread "main" java.lang.NullPointerException
	at
freemarker.core.BlockAssignment.getCanonicalForm(BlockAssignment.java:15
0)
	at
freemarker.core.MixedContent.getCanonicalForm(MixedContent.java:100)
	at CanonicalTest.main(CanonicalTest.java:11)


This template will succeed:
---Passing Template---
<#ftl>
<#assign x> </#assign>

I believe freemarker-2.3.12/src/freemarker/core/BlockAssignment.java
needs to have this:
---Suggested Fix---
  public String getCanonicalForm() {
   ...
        return "<#" + key + " " + varName + 
            (namespaceExp != null ? " in " +
namespaceExp.getCanonicalForm() : "") 
            + ">" + (nestedBlock != null ?
nestedBlock.getCanonicalForm() : "") + "</#" + key + ">";
    }


Leigh.

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