don't try to re-rename a target that failed to be renamed in the first place. Related to PR 41525.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@692082 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/unix/Symlink.java

@@ -432,9 +432,11 @@ public class Symlink extends DispatchTask {
                                FILE_UTILS.removeLeadingPath(canfil, linkfil));
         }
 
+        boolean renamedTarget = false;
         try {
             try {
                 FILE_UTILS.rename(canfil, temp);
+                renamedTarget = true;
             } catch (IOException e) {
                 throw new IOException(
                     "Couldn't rename resource when attempting to delete "
@@ -446,6 +448,7 @@ public class Symlink extends DispatchTask {
                     + " (was it a real file? is this not a UNIX system?)");
             }
         } finally {
+            if (renamedTarget) {
             // return the resource to its original name:
             try {
                 FILE_UTILS.rename(temp, canfil);
@@ -455,6 +458,7 @@ public class Symlink extends DispatchTask {
                     + "\n THE RESOURCE'S NAME ON DISK HAS "
                     + "BEEN CHANGED BY THIS ERROR!\n");
             }
+            }
         }
     }