#26 Support combine.keys (in sync with xml-combiner implementation)

Author: rfscholte

src/main/java/org/codehaus/plexus/util/xml/Xpp3DomUtils.java

@@ -171,11 +171,12 @@ private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boole
                 }
             }
 
+            final String keysValue = recessive.getAttribute( KEYS_COMBINATION_MODE_ATTRIBUTE );
+
             Xpp3Dom[] children = recessive.getChildren();
             for ( Xpp3Dom recessiveChild : children )
             {
                 String idValue = recessiveChild.getAttribute( ID_COMBINATION_MODE_ATTRIBUTE );
-                String keysValue = recessiveChild.getAttribute( KEYS_COMBINATION_MODE_ATTRIBUTE );
 
                 Xpp3Dom childDom = null;
                 if ( isNotEmpty( idValue ) )
@@ -196,15 +197,15 @@ else if ( isNotEmpty( keysValue ) )
                     Map<String, String> recessiveKeyValues = new HashMap<String, String>( keys.length );
                     for ( String key : keys )
                     {
-                        recessiveKeyValues.put( key, recessiveChild.getChild( key ).getValue() );
+                        recessiveKeyValues.put( key, recessiveChild.getAttribute( key ) );
                     }
 
                     for ( Xpp3Dom dominantChild : dominant.getChildren() )
                     {
                         Map<String, String> dominantKeyValues = new HashMap<String, String>( keys.length );
                         for ( String key : keys )
                         {
-                            dominantKeyValues.put( key, dominantChild.getChild( key ).getValue() );
+                            dominantKeyValues.put( key, dominantChild.getAttribute( key ) );
                         }
 
                         if ( recessiveKeyValues.equals( dominantKeyValues ) )

src/test/java/org/codehaus/plexus/util/xml/Xpp3DomUtilsTest.java

@@ -64,10 +64,10 @@ public void testCombineId()
     public void testCombineKeys()
         throws Exception
     {
-        String lhs = "<props>" + "<property combine.keys='name'><name>LHS-ONLY</name><value>LHS</value></property>"
+        String lhs = "<props combine.keys='key'>" + "<property key=\"LHS-ONLY\"><name>LHS-ONLY</name><value>LHS</value></property>"
                         + "<property combine.keys='name'><name>TOOVERWRITE</name><value>LHS</value></property>" + "</props>";
 
-        String rhs = "<props>" + "<property combine.keys='name'><name>RHS-ONLY</name><value>RHS</value></property>"
+        String rhs = "<props combine.keys='key'>" + "<property key=\"RHS-ONLY\"><name>RHS-ONLY</name><value>RHS</value></property>"
             + "<property combine.keys='name'><name>TOOVERWRITE</name><value>RHS</value></property>" + "</props>";
 
         Xpp3Dom leftDom = Xpp3DomBuilder.build( new StringReader( lhs ), new FixedInputLocationBuilder( "left" ) );