Throw in a reuseloadedstylesheet attribute for <style> (feel free to

come up with a better name).  This provides a workaround for a bug in
Xalan-J - the version that gets distributed with JDK 1.4.1.

PR: 13859

based on a patch submitted by:	Jens Elkner <elkner at linofee.org>


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273545 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -106,6 +106,9 @@ Other changes:
 
 * Shipped XML parser is now Xerces 2.2.1
 
+* <style> has a new attribute reuseloadedstylesheet to work around a
+  bug in widespread Xalan versions.
+
 Changes from Ant 1.5.1Beta1 to 1.5.1
 ====================================
 

docs/manual/CoreTasks/style.html

@@ -151,6 +151,14 @@ element which is used to perform Entity and URI resolution</p>
       directories.  Default is <code>true</code></td>
     <td valign="top" align="center">No</td>
   </tr>
+  <tr>
+    <td valign="top">reuseloadedstylesheet</td>
+    <td valign="top">Reuse the same transformer when transforming
+    multiple files.  If you set this to false, performance will
+    suffer, but you may work around a bug in certain Xalan-J versions.
+    Default is <code>true</code>.  <em>Since Ant 1.6</em>.</td>
+    <td valign="top" align="center">No</td>
+  </tr>
 </table>
 <h3>Parameters specified as nested elements</h3>
 <h4>classpath</h4>

src/main/org/apache/tools/ant/taskdefs/XSLTProcess.java

@@ -157,6 +157,12 @@ public class XSLTProcess extends MatchingTask implements XSLTLogger {
      */
     private Factory factory = null;
 
+    /**
+     * whether to reuse Transformer if transforming multiple files.
+     * @since 1.6
+     */
+    private boolean reuseLoadedStylesheet = true;
+
     /**
      * Creates a new XSLTProcess Task.
      */
@@ -175,6 +181,19 @@ public class XSLTProcess extends MatchingTask implements XSLTLogger {
         performDirectoryScan = b;
     }
 
+    /**
+     * Whether to reuse the transformer instance when transforming
+     * multiple files.
+     *
+     * <p>Setting this to false may get around a bug in certain
+     * Xalan-J version, default is true.</p>
+     *
+     * @since Ant 1.6
+     */
+    public void setReuseLoadedStylesheet(boolean b) {
+        reuseLoadedStylesheet = b;
+    }
+
     /**
      * Executes the task.
      *
@@ -713,7 +732,7 @@ public class XSLTProcess extends MatchingTask implements XSLTLogger {
      * @exception BuildException if the stylesheet cannot be loaded.
      */
     protected void configureLiaison(File stylesheet) throws BuildException {
-        if (stylesheetLoaded) {
+        if (stylesheetLoaded && reuseLoadedStylesheet) {
             return;
         }
         stylesheetLoaded = true;