Fix NPE in <concat>.

PR: 14310


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273518 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -42,6 +42,9 @@ Fixed bugs:
 * <replace> would count some internal character replacements when
   reporting the number of replaced tokens.
 
+* <concat> would cause an exception if a <filelist> pointed to files
+  that do not exist.
+
 Other changes:
 --------------
 

src/etc/testcases/taskdefs/concat.xml

@@ -31,4 +31,10 @@
     <concat>Hello, ${world}!</concat>
   </target>
 
+  <target name="test6">
+    <concat destfile="TESTDEST" append="true">
+      <filelist dir="${basedir}" files="thisfiledoesnotexist"/>
+    </concat>
+  </target>
+
 </project>

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

@@ -298,9 +298,8 @@ public class Concat extends Task {
     private void catFiles(File base, String[] files) {
 
         // First, create a list of absolute paths for the input files.
-        final int len = files.length;
-        String[] input = new String[len];
-        for (int i = 0; i < len; i++) {
+        Vector inputFileNames = new Vector();
+        for (int i = 0; i < files.length; i++) {
 
             File current = new File(base, files[i]);
 
@@ -314,9 +313,13 @@ public class Concat extends Task {
                 continue;
             }
 
-            input[i] = current.getAbsolutePath();
+            inputFileNames.addElement(current.getAbsolutePath());
         }
 
+        final int len = inputFileNames.size();
+        String[] input = new String[len];
+        inputFileNames.copyInto(input);
+
         // Next, perform the concatenation.
         if (encoding == null) {
             OutputStream os = null;

src/testcases/org/apache/tools/ant/taskdefs/ConcatTest.java

@@ -161,4 +161,9 @@ public class ConcatTest
         expectLog("test5", "Hello, World!");
     }
 
+    public void test6() {
+        expectLogContaining("test6", 
+                            "src/etc/testcases/taskdefs/thisfiledoesnotexist does not exist.");
+    }
+
 }