replacetokens failed if stream ends in begintoken. PR 47306.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@781357 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -371,6 +371,10 @@ Fixed bugs:
    errors.
    Bugzilla Report 46829.
 
+ * The <replacetokens> filter threw an exception if the stream to
+   filter ended with a begin token.
+   Bugzilla Report 47306.
+
 Other changes:
 --------------
  * A HostInfo task was added performing information on hosts, including info on 

src/main/org/apache/tools/ant/filters/ReplaceTokens.java

@@ -153,7 +153,11 @@ public final class ReplaceTokens
                     queuedData
                         = key.toString() + queuedData.substring(queueIndex);
                 }
-                queueIndex = 0;
+                if (queuedData.length() > 0) {
+                    queueIndex = 0;
+                } else {
+                    queueIndex = -1;
+                }
                 return beginToken;
             } else {
                 key.setLength(key.length() - 1);

src/tests/antunit/filters/replacetokens-test.xml

@@ -47,4 +47,22 @@ world=Ant
        resource="${output}/text.txt" value="Hello, Ant!"/>
   </target>
 
+  <target name="testFileEndsWithToken"
+          description="https://issues.apache.org/bugzilla/show_bug.cgi?id=47306"
+          depends="setUp">
+    <mkdir dir="${output}"/>
+    <echo file="${input}/test47306.txt">Hello@</echo>
+    <copy todir="${output}">
+      <fileset dir="${input}"/>
+      <filterchain>
+        <replacetokens>
+          <token key="foo" value="bar"/>
+        </replacetokens>
+      </filterchain>
+    </copy>
+    <au:assertFilesMatch
+       expected="${input}/test47306.txt"
+       actual="${output}/test47306.txt"/>
+  </target>
+
 </project>