From ec3031196a2134377fa1ba509847495f60de38be Mon Sep 17 00:00:00 2001
From: Stefan Bodewig <bodewig@apache.org>
Date: Tue, 12 Nov 2002 11:58:28 +0000
Subject: [PATCH] Print a warning and don't create an output file if there is
 no input to <concat>.

PR: 14310
Submitted by:	Gus Heck <gus.heck at olin.edu>


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273539 13f79535-47bb-0310-9956-ffa450edef68
---
 src/etc/testcases/taskdefs/concat.xml              | 4 +++-
 src/main/org/apache/tools/ant/taskdefs/Concat.java | 9 +++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/etc/testcases/taskdefs/concat.xml b/src/etc/testcases/taskdefs/concat.xml
index 029ec0cbf..811ccd84d 100644
--- a/src/etc/testcases/taskdefs/concat.xml
+++ b/src/etc/testcases/taskdefs/concat.xml
@@ -35,7 +35,9 @@
     <concat destfile="TESTDEST" append="true">
       <filelist dir="${basedir}" files="thisfiledoesnotexist"/>
     </concat>
-    <delete file="TESTDEST"/>
+    <available file="TESTDEST" property="TESTDEST.was.created"/>
+    <fail message="TESTDEST created for nonexistant files"
+          if="TESTDEST.was.created"/>
   </target>
 
 </project>
diff --git a/src/main/org/apache/tools/ant/taskdefs/Concat.java b/src/main/org/apache/tools/ant/taskdefs/Concat.java
index fcf90b23d..ced15d928 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Concat.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Concat.java
@@ -266,6 +266,9 @@ public class Concat extends Task {
                 // Concatenate the files.
                 if (srcFiles != null) {
                     catFiles(fileSetBase, srcFiles);
+                } else {
+                    log("Warning: Concat received empty fileset.", 
+                        Project.MSG_WARN);
                 }
             }
         } finally {
@@ -317,6 +320,12 @@ public class Concat extends Task {
         }
 
         final int len = inputFileNames.size();
+        if (len == 0) {
+            log("Warning: Could not find any of the files specified " +
+                "in concat task.", Project.MSG_WARN);
+            return;
+        }
+
         String[] input = new String[len];
         inputFileNames.copyInto(input);