as discussed on dev@, allow <mapper refid> to refer to a FileNameMapper

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@495014 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -55,6 +55,8 @@ Other changes:
 * Show Previous Revision in the tagdiff.xsl stylesheet
   Bugzilla 29143
 
+* Allow <mapper refid> to refer directly to a FileNameMapper instance.
+
 Changes from Ant 1.6.5 to Ant 1.7.0
 ===================================
 

src/main/org/apache/tools/ant/types/Mapper.java

@@ -198,7 +198,18 @@ public class Mapper extends DataType implements Cloneable {
      */
     public FileNameMapper getImplementation() throws BuildException {
         if (isReference()) {
-            return getRef().getImplementation();
+            dieOnCircularReference();
+            Reference r = getRefid();
+            Object o = r.getReferencedObject(getProject());
+            if (o instanceof FileNameMapper) {
+                return (FileNameMapper) o;
+            }
+            if (o instanceof Mapper) {
+                return ((Mapper) o).getImplementation();
+            }
+            String od = o == null ? "null" : o.getClass().getName();
+            throw new BuildException(od + " at reference '"
+                + r.getRefId() + "' is not a valid mapper reference.");
         }
 
         if (type == null && classname == null && container == null) {
@@ -256,6 +267,8 @@ public class Mapper extends DataType implements Cloneable {
     /**
      * Performs the check for circular references and returns the
      * referenced Mapper.
+     * @deprecated since Ant 1.7.1 because a mapper might ref a
+     *             FileNameMapper implementation directly.
      * @return the referenced Mapper
      */
     protected Mapper getRef() {

src/tests/antunit/types/mapper-ref.xml

@@ -0,0 +1,38 @@
+<!-- does not address/replace the circular reference checks, etc.
+     in MapperTest.java (yet).
+ -->
+
+<project xmlns:au="antlib:org.apache.ant.antunit">
+  <macrodef name="test">
+    <sequential>
+      <pathconvert property="dest">
+        <string value="foo" />
+        <mapper refid="mapper" />
+      </pathconvert>
+      <au:assertTrue>
+        <equals arg1="${dest}" arg2="bar" />
+      </au:assertTrue>
+    </sequential>
+  </macrodef>
+
+  <target name="testBasic" description="success">
+    <mapper id="mapper" type="merge" to="bar" />
+    <test />
+  </target>
+
+  <target name="testFileNameMapper" description="success">
+    <mergemapper id="mapper" to="bar" />
+    <test />
+  </target>
+
+  <target name="testWrongType" description="failure">
+    <path id="mapper" path="whocares" />
+    <au:expectfailure 
+      expectedMessage="org.apache.tools.ant.types.Path at reference 'mapper' is not a valid mapper reference.">
+      <test />
+    </au:expectfailure>
+  </target>
+
+  <target name="all" depends="testBasic,testFileNameMapper,testWrongType" />
+
+</project>