#61 keep input location while merging

hboutemy · hboutemy · commit dd8d35ae706d · 2019-03-09T17:35:38.000+01:00
diff --git a/src/main/java/org/codehaus/plexus/util/xml/Xpp3Dom.java b/src/main/java/org/codehaus/plexus/util/xml/Xpp3Dom.java
@@ -91,6 +91,15 @@ public Xpp3Dom( String name )
         childMap = new HashMap<String, Xpp3Dom>();
     }
 
+    /**
+     * @since 3.2.0
+     */
+    public Xpp3Dom( String name, Object inputLocation )
+    {
+        this( name );
+        this.inputLocation = inputLocation;
+    }
+
     /**
      * Copy constructor.
      */
@@ -105,6 +114,7 @@ public Xpp3Dom( Xpp3Dom src )
     public Xpp3Dom( Xpp3Dom src, String name )
     {
         this.name = name;
+        this.inputLocation = src.inputLocation;
 
         int childCount = src.getChildCount();
 
@@ -321,23 +331,41 @@ public void writeToSerializer( String namespace, XmlSerializer serializer )
     }
 
     /**
-     * Merges one DOM into another, given a specific algorithm and possible override points for that algorithm. The
-     * algorithm is as follows: 1. if the recessive DOM is null, there is nothing to do...return. 2. Determine whether
-     * the dominant node will suppress the recessive one (flag=mergeSelf). A. retrieve the 'combine.self' attribute on
-     * the dominant node, and try to match against 'override'... if it matches 'override', then set mergeSelf ==
-     * false...the dominant node suppresses the recessive one completely. B. otherwise, use the default value for
-     * mergeSelf, which is true...this is the same as specifying 'combine.self' == 'merge' as an attribute of the
-     * dominant root node. 3. If mergeSelf == true A. if the dominant root node's value is empty, set it to the
-     * recessive root node's value B. For each attribute in the recessive root node which is not set in the dominant
-     * root node, set it. C. Determine whether children from the recessive DOM will be merged or appended to the
-     * dominant DOM as siblings (flag=mergeChildren). i. if childMergeOverride is set (non-null), use that value
-     * (true/false) ii. retrieve the 'combine.children' attribute on the dominant node, and try to match against
-     * 'append'...if it matches 'append', then set mergeChildren == false...the recessive children will be appended as
-     * siblings of the dominant children. iii. otherwise, use the default value for mergeChildren, which is true...this
-     * is the same as specifying 'combine.children' == 'merge' as an attribute on the dominant root node. D. Iterate
-     * through the recessive children, and: i. if mergeChildren == true and there is a corresponding dominant child
-     * (matched by element name), merge the two. ii. otherwise, add the recessive child as a new child on the dominant
-     * root node.
+     * Merges one DOM into another, given a specific algorithm and possible override points for that algorithm.<p>
+     * The algorithm is as follows:
+     * <ol>
+     * <li> if the recessive DOM is null, there is nothing to do... return.</li>
+     * <li> Determine whether the dominant node will suppress the recessive one (flag=mergeSelf).
+     *   <ol type="A">
+     *   <li> retrieve the 'combine.self' attribute on the dominant node, and try to match against 'override'...
+     *        if it matches 'override', then set mergeSelf == false...the dominant node suppresses the recessive one
+     *        completely.</li>
+     *   <li> otherwise, use the default value for mergeSelf, which is true...this is the same as specifying
+     *        'combine.self' == 'merge' as an attribute of the dominant root node.</li>
+     *   </ol></li>
+     * <li> If mergeSelf == true
+     *   <ol type="A">
+     *   <li> if the dominant root node's value is empty, set it to the recessive root node's value</li>
+     *   <li> For each attribute in the recessive root node which is not set in the dominant root node, set it.</li>
+     *   <li> Determine whether children from the recessive DOM will be merged or appended to the dominant DOM as
+     *        siblings (flag=mergeChildren).
+     *     <ol type="i">
+     *     <li> if childMergeOverride is set (non-null), use that value (true/false)</li>
+     *     <li> retrieve the 'combine.children' attribute on the dominant node, and try to match against
+     *          'append'...</li>
+     *     <li> if it matches 'append', then set mergeChildren == false...the recessive children will be appended as
+     *          siblings of the dominant children.</li>
+     *     <li> otherwise, use the default value for mergeChildren, which is true...this is the same as specifying
+     *         'combine.children' == 'merge' as an attribute on the dominant root node.</li>
+     *     </ol></li>
+     *   <li> Iterate through the recessive children, and:
+     *     <ol type="i">
+     *     <li> if mergeChildren == true and there is a corresponding dominant child (matched by element name),
+     *          merge the two.</li>
+     *     <li> otherwise, add the recessive child as a new child on the dominant root node.</li>
+     *     </ol></li>
+     *   </ol></li>
+     * </ol>
      */
     private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boolean childMergeOverride )
     {
@@ -358,9 +386,10 @@ private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boole
 
         if ( mergeSelf )
         {
-            if ( isEmpty( dominant.getValue() ) )
+            if ( isEmpty( dominant.getValue() ) && !isEmpty( recessive.getValue() ) )
             {
                 dominant.setValue( recessive.getValue() );
+                dominant.setInputLocation( recessive.getInputLocation() );
             }
 
             String[] recessiveAttrs = recessive.getAttributeNames();
diff --git a/src/main/java/org/codehaus/plexus/util/xml/Xpp3DomUtils.java b/src/main/java/org/codehaus/plexus/util/xml/Xpp3DomUtils.java
@@ -19,6 +19,10 @@
 import org.codehaus.plexus.util.xml.pull.XmlSerializer;
 
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
 
 /** @author Jason van Zyl */
 public class Xpp3DomUtils
@@ -71,24 +75,43 @@ public void writeToSerializer( String namespace, XmlSerializer serializer, Xpp3D
     }
 
     /**
-     * Merges one DOM into another, given a specific algorithm and possible override points for that algorithm. The
-     * algorithm is as follows: 1. if the recessive DOM is null, there is nothing to do...return. 2. Determine whether
-     * the dominant node will suppress the recessive one (flag=mergeSelf). A. retrieve the 'combine.self' attribute on
-     * the dominant node, and try to match against 'override'... if it matches 'override', then set mergeSelf ==
-     * false...the dominant node suppresses the recessive one completely. B. otherwise, use the default value for
-     * mergeSelf, which is true...this is the same as specifying 'combine.self' == 'merge' as an attribute of the
-     * dominant root node. 3. If mergeSelf == true A. if the dominant root node's value is empty, set it to the
-     * recessive root node's value B. For each attribute in the recessive root node which is not set in the dominant
-     * root node, set it. C. Determine whether children from the recessive DOM will be merged or appended to the
-     * dominant DOM as siblings (flag=mergeChildren). i. if childMergeOverride is set (non-null), use that value
-     * (true/false) ii. retrieve the 'combine.children' attribute on the dominant node, and try to match against
-     * 'append'...if it matches 'append', then set mergeChildren == false...the recessive children will be appended as
-     * siblings of the dominant children. iii. otherwise, use the default value for mergeChildren, which is true...this
-     * is the same as specifying 'combine.children' == 'merge' as an attribute on the dominant root node. D. Iterate
-     * through the recessive children, and: i. if 'combine.id' is set and there is a corresponding dominant child
-     * (matched by value of 'combine.id'), merge the two. ii. if mergeChildren == true and there is a corresponding
-     * dominant child (matched by element name), merge the two. iii. otherwise, add the recessive child as a new child
-     * on the dominant root node.
+     * Merges one DOM into another, given a specific algorithm and possible override points for that algorithm.<p>
+     * The algorithm is as follows:
+     * <ol>
+     * <li> if the recessive DOM is null, there is nothing to do... return.</li>
+     * <li> Determine whether the dominant node will suppress the recessive one (flag=mergeSelf).
+     *   <ol type="A">
+     *   <li> retrieve the 'combine.self' attribute on the dominant node, and try to match against 'override'...
+     *        if it matches 'override', then set mergeSelf == false...the dominant node suppresses the recessive one
+     *        completely.</li>
+     *   <li> otherwise, use the default value for mergeSelf, which is true...this is the same as specifying
+     *        'combine.self' == 'merge' as an attribute of the dominant root node.</li>
+     *   </ol></li>
+     * <li> If mergeSelf == true
+     *   <ol type="A">
+     *   <li> if the dominant root node's value is empty, set it to the recessive root node's value</li>
+     *   <li> For each attribute in the recessive root node which is not set in the dominant root node, set it.</li>
+     *   <li> Determine whether children from the recessive DOM will be merged or appended to the dominant DOM as
+     *        siblings (flag=mergeChildren).
+     *     <ol type="i">
+     *     <li> if childMergeOverride is set (non-null), use that value (true/false)</li>
+     *     <li> retrieve the 'combine.children' attribute on the dominant node, and try to match against
+     *          'append'...</li>
+     *     <li> if it matches 'append', then set mergeChildren == false...the recessive children will be appended as
+     *          siblings of the dominant children.</li>
+     *     <li> otherwise, use the default value for mergeChildren, which is true...this is the same as specifying
+     *          'combine.children' == 'merge' as an attribute on the dominant root node.</li>
+     *     </ol></li>
+     *   <li> Iterate through the recessive children, and:
+     *     <ol type="i">
+     *     <li> if 'combine.id' is set and there is a corresponding dominant child (matched by value of 'combine.id'),
+     *          merge the two.</li>
+     *     <li> if mergeChildren == true and there is a corresponding dominant child (matched by element name),
+     *          merge the two.</li>
+     *     <li> otherwise, add the recessive child as a new child on the dominant root node.</li>
+     *     </ol></li>
+     *   </ol></li>
+     * </ol>
      */
     private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boolean childMergeOverride )
     {
@@ -109,9 +132,10 @@ private static void mergeIntoXpp3Dom( Xpp3Dom dominant, Xpp3Dom recessive, Boole
 
         if ( mergeSelf )
         {
-            if ( isEmpty( dominant.getValue() ) )
+            if ( isEmpty( dominant.getValue() ) && !isEmpty( recessive.getValue() ) )
             {
                 dominant.setValue( recessive.getValue() );
+                dominant.setInputLocation( recessive.getInputLocation() );
             }
 
             String[] recessiveAttrs = recessive.getAttributeNames();
diff --git a/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomTest.java b/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomTest.java
@@ -27,6 +27,7 @@
 import java.io.StringReader;
 import java.util.HashMap;
 
+import org.codehaus.plexus.util.xml.pull.XmlPullParser;
 import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
 import org.junit.Test;
 
@@ -38,24 +39,34 @@ public void testShouldPerformAppendAtFirstSubElementLevel()
         // create the dominant DOM
         Xpp3Dom t1 = new Xpp3Dom( "top" );
         t1.setAttribute( Xpp3Dom.CHILDREN_COMBINATION_MODE_ATTRIBUTE, Xpp3Dom.CHILDREN_COMBINATION_APPEND );
+        t1.setInputLocation( "t1top" );
 
         Xpp3Dom t1s1 = new Xpp3Dom( "topsub1" );
         t1s1.setValue( "t1s1Value" );
+        t1s1.setInputLocation( "t1s1" );
 
         t1.addChild( t1s1 );
 
         // create the recessive DOM
         Xpp3Dom t2 = new Xpp3Dom( "top" );
+        t2.setInputLocation( "t2top" );
 
         Xpp3Dom t2s1 = new Xpp3Dom( "topsub1" );
         t2s1.setValue( "t2s1Value" );
+        t2s1.setInputLocation( "t2s1" );
 
         t2.addChild( t2s1 );
 
         // merge and check results.
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( t1, t2 );
 
         assertEquals( 2, result.getChildren( "topsub1" ).length );
+        assertEquals( "t2s1Value", result.getChildren( "topsub1" )[0].getValue() );
+        assertEquals( "t1s1Value", result.getChildren( "topsub1" )[1].getValue() );
+
+        assertEquals( "t1top", result.getInputLocation() );
+        assertEquals( "t2s1", result.getChildren( "topsub1" )[0].getInputLocation() );
+        assertEquals( "t1s1", result.getChildren( "topsub1" )[1].getInputLocation() );
     }
 
     @Test
@@ -64,24 +75,32 @@ public void testShouldOverrideAppendAndDeepMerge()
         // create the dominant DOM
         Xpp3Dom t1 = new Xpp3Dom( "top" );
         t1.setAttribute( Xpp3Dom.CHILDREN_COMBINATION_MODE_ATTRIBUTE, Xpp3Dom.CHILDREN_COMBINATION_APPEND );
+        t1.setInputLocation( "t1top" );
 
         Xpp3Dom t1s1 = new Xpp3Dom( "topsub1" );
         t1s1.setValue( "t1s1Value" );
+        t1s1.setInputLocation( "t1s1" );
 
         t1.addChild( t1s1 );
 
         // create the recessive DOM
         Xpp3Dom t2 = new Xpp3Dom( "top" );
+        t2.setInputLocation( "t2top" );
 
         Xpp3Dom t2s1 = new Xpp3Dom( "topsub1" );
         t2s1.setValue( "t2s1Value" );
+        t2s1.setInputLocation( "t2s1" );
 
         t2.addChild( t2s1 );
 
         // merge and check results.
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( t1, t2, Boolean.TRUE );
 
         assertEquals( 1, result.getChildren( "topsub1" ).length );
+        assertEquals( "t1s1Value", result.getChildren( "topsub1" )[0].getValue() );
+
+        assertEquals( "t1top", result.getInputLocation() );
+        assertEquals( "t1s1", result.getChildren( "topsub1" )[0].getInputLocation() );
     }
 
     @Test
@@ -90,19 +109,22 @@ public void testShouldPerformSelfOverrideAtTopLevel()
         // create the dominant DOM
         Xpp3Dom t1 = new Xpp3Dom( "top" );
         t1.setAttribute( "attr", "value" );
+        t1.setInputLocation( "t1top" );
 
         t1.setAttribute( Xpp3Dom.SELF_COMBINATION_MODE_ATTRIBUTE, Xpp3Dom.SELF_COMBINATION_OVERRIDE );
 
         // create the recessive DOM
         Xpp3Dom t2 = new Xpp3Dom( "top" );
         t2.setAttribute( "attr2", "value2" );
         t2.setValue( "t2Value" );
+        t2.setInputLocation( "t2top" );
 
         // merge and check results.
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( t1, t2 );
 
         assertEquals( 2, result.getAttributeNames().length );
         assertNull( result.getValue() );
+        assertEquals( "t1top", result.getInputLocation() );
     }
 
     @Test
@@ -111,11 +133,13 @@ public void testShouldMergeValuesAtTopLevelByDefault()
         // create the dominant DOM
         Xpp3Dom t1 = new Xpp3Dom( "top" );
         t1.setAttribute( "attr", "value" );
+        t1.setInputLocation( "t1top" );
 
         // create the recessive DOM
         Xpp3Dom t2 = new Xpp3Dom( "top" );
         t2.setAttribute( "attr2", "value2" );
         t2.setValue( "t2Value" );
+        t2.setInputLocation( "t2top" );
 
         // merge and check results.
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( t1, t2 );
@@ -124,6 +148,7 @@ public void testShouldMergeValuesAtTopLevelByDefault()
         assertEquals( 2, result.getAttributeNames().length );
 
         assertEquals( result.getValue(), t2.getValue() );
+        assertEquals( "t2top", result.getInputLocation() );
     }
 
     @Test
@@ -213,10 +238,12 @@ public void testShouldOverwritePluginConfigurationSubItemsByDefault()
         throws XmlPullParserException, IOException
     {
         String parentConfigStr = "<configuration><items><item>one</item><item>two</item></items></configuration>";
-        Xpp3Dom parentConfig = Xpp3DomBuilder.build( new StringReader( parentConfigStr ) );
+        Xpp3Dom parentConfig =
+            Xpp3DomBuilder.build( new StringReader( parentConfigStr ), new FixedInputLocationBuilder( "parent" ) );
 
         String childConfigStr = "<configuration><items><item>three</item></items></configuration>";
-        Xpp3Dom childConfig = Xpp3DomBuilder.build( new StringReader( childConfigStr ) );
+        Xpp3Dom childConfig =
+            Xpp3DomBuilder.build( new StringReader( childConfigStr ), new FixedInputLocationBuilder( "child" ) );
 
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( childConfig, parentConfig );
         Xpp3Dom items = result.getChild( "items" );
@@ -225,18 +252,21 @@ public void testShouldOverwritePluginConfigurationSubItemsByDefault()
 
         Xpp3Dom item = items.getChild( 0 );
         assertEquals( "three", item.getValue() );
+        assertEquals( "child", item.getInputLocation() );
     }
 
     @Test
     public void testShouldMergePluginConfigurationSubItemsWithMergeAttributeSet()
         throws XmlPullParserException, IOException
     {
         String parentConfigStr = "<configuration><items><item>one</item><item>two</item></items></configuration>";
-        Xpp3Dom parentConfig = Xpp3DomBuilder.build( new StringReader( parentConfigStr ) );
+        Xpp3Dom parentConfig =
+            Xpp3DomBuilder.build( new StringReader( parentConfigStr ), new FixedInputLocationBuilder( "parent" ) );
 
         String childConfigStr =
             "<configuration><items combine.children=\"append\"><item>three</item></items></configuration>";
-        Xpp3Dom childConfig = Xpp3DomBuilder.build( new StringReader( childConfigStr ) );
+        Xpp3Dom childConfig =
+            Xpp3DomBuilder.build( new StringReader( childConfigStr ), new FixedInputLocationBuilder( "child" ) );
 
         Xpp3Dom result = Xpp3Dom.mergeXpp3Dom( childConfig, parentConfig );
         Xpp3Dom items = result.getChild( "items" );
@@ -246,8 +276,11 @@ public void testShouldMergePluginConfigurationSubItemsWithMergeAttributeSet()
         Xpp3Dom[] item = items.getChildren();
 
         assertEquals( "one", item[0].getValue() );
+        assertEquals( "parent", item[0].getInputLocation() );
         assertEquals( "two", item[1].getValue() );
+        assertEquals( "parent", item[1].getInputLocation() );
         assertEquals( "three", item[2].getValue() );
+        assertEquals( "child", item[2].getInputLocation() );
     }
 
     @Test
@@ -295,4 +328,20 @@ public void testDupeChildren()
         assertNotNull( dom );
         assertEquals( "y", dom.getChild( "foo" ).getValue() );
     }
+
+    private static class FixedInputLocationBuilder
+        implements Xpp3DomBuilder.InputLocationBuilder
+    {
+        private final Object location;
+
+        public FixedInputLocationBuilder( Object location )
+        {
+            this.location = location;
+        }
+
+        public Object toInputLocation( XmlPullParser parser )
+        {
+            return location;
+        }
+    }
 }
diff --git a/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomUtilsTest.java b/src/test/java/org/codehaus/plexus/util/xml/Xpp3DomUtilsTest.java
