diff --git a/WHATSNEW b/WHATSNEW
index cc13a8fda..13c10002e 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -70,6 +70,9 @@ Fixed bugs:
  * <sync> only supported a single non-fileset resource collection even
    though the manual said it could be multiple.
 
+ * <sync> didn't work properly when working on resource collections.
+   Bugzilla Report 51462.
+
 Other changes:
 --------------
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/Sync.java b/src/main/org/apache/tools/ant/taskdefs/Sync.java
index 1f7210ae1..692726002 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Sync.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Sync.java
@@ -487,13 +487,10 @@ public class Sync extends Task {
         protected Map scan(Resource[] resources, File toDir) {
             assertTrue("No mapper", mapperElement == null);
 
-            Map m = super.scan(resources, toDir);
-
-            Iterator iter = m.keySet().iterator();
-            while (iter.hasNext()) {
-                nonOrphans.add(((Resource) iter.next()).getName());
+            for (int i = 0; i < resources.length; i++) {
+                nonOrphans.add(resources[i].getName());
             }
-            return m;
+            return super.scan(resources, toDir);
         }
 
         /**
diff --git a/src/tests/antunit/taskdefs/sync-test.xml b/src/tests/antunit/taskdefs/sync-test.xml
index e6b202a3d..21a14426e 100644
--- a/src/tests/antunit/taskdefs/sync-test.xml
+++ b/src/tests/antunit/taskdefs/sync-test.xml
@@ -151,4 +151,25 @@
     </sync>
   </target>
 
+  <target name="testSyncWithResources" depends="setUp"
+          description="https://issues.apache.org/bugzilla/show_bug.cgi?id=51462">
+    <sync todir="${output}">
+      <mappedresources>
+        <fileset dir="${input}"/>
+        <globmapper from="*" to="test/*"/>
+      </mappedresources>
+    </sync>
+    <au:assertFileDoesntExist file="${output}/bar.txt"/>
+    <au:assertFileExists file="${output}/test/a/foo.txt"/>
+
+    <sync todir="${output}">
+      <mappedresources>
+        <fileset dir="${input}"/>
+        <globmapper from="*" to="test/*"/>
+      </mappedresources>
+    </sync>
+    <au:assertFileDoesntExist file="${output}/bar.txt"/>
+    <au:assertFileExists file="${output}/test/a/foo.txt"/>
+  </target>
+
 </project>