fixed a problem where Hudson fails to wipe out files in a directory if the...

fixed a problem where Hudson fails to wipe out files in a directory if the directory is not writable.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@8724 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Util.java

@@ -153,10 +153,36 @@ public class Util {
                 return;
 
             // perhaps this file is read-only?
+            makeWritable(f);
+            /*
+             on Unix both the file and the directory that contains it has to be writable
+             for a file deletion to be successful. (Confirmed on Solaris 9)
+
+             $ ls -la
+             total 6
+             dr-xr-sr-x   2 hudson   hudson       512 Apr 18 14:41 .
+             dr-xr-sr-x   3 hudson   hudson       512 Apr 17 19:36 ..
+             -r--r--r--   1 hudson   hudson       469 Apr 17 19:36 manager.xml
+             -rw-r--r--   1 hudson   hudson         0 Apr 18 14:41 x
+             $ rm x
+             rm: x not removed: Permission denied
+             */
+
+            makeWritable(f.getParentFile());
+
+            if(!f.delete() && f.exists())
+                throw new IOException("Unable to delete " + f.getPath());
+        }
+    }
+
+    /**
+     * Makes the given file writable.
+     */
+    private static void makeWritable(File f) {
         // try chmod. this becomes no-op if this is not Unix.
         try {
             Chmod chmod = new Chmod();
-                chmod.setProject(new org.apache.tools.ant.Project());
+            chmod.setProject(new Project());
             chmod.setFile(f);
             chmod.setPerm("u+w");
             chmod.execute();
@@ -170,10 +196,6 @@ public class Util {
         } catch (NoSuchMethodError e) {
             // not JDK6
         }
-
-            if(!f.delete() && f.exists())
-                throw new IOException("Unable to delete " + f.getPath());
-        }
     }
 
     public static void deleteRecursive(File dir) throws IOException {