Subversion Release Manager

    /**
     * Either run "svn co" or "svn up" equivalent.
     */
    private static class CheckOutTask implements FileCallable<List<External>> {
        private final ISVNAuthenticationProvider authProvider;
        private final Date timestamp;
        // true to "svn update", false to "svn checkout".
        private boolean update;
        private final TaskListener listener;
        private final ModuleLocation[] locations;
        //EDIT (1) next line added by piascikj for building specific revision
        private String revision;

        public CheckOutTask(AbstractBuild<?, ?> build, SubversionSCM parent, Date timestamp, boolean update, TaskListener listener) {
            this.authProvider = parent.getDescriptor().createAuthenticationProvider();
            this.timestamp = timestamp;
            this.update = update;
            this.listener = listener;
            this.locations = parent.getLocations(build);
            //EDIT (2) next line added by piascikj for building specific revision
            this.revision = build.getEnvVars().get("REVISION");
        }

        public List<External> invoke(File ws, VirtualChannel channel) throws IOException {
            final SVNClientManager manager = createSvnClientManager(authProvider);
            try {
                final SVNUpdateClient svnuc = manager.getUpdateClient();
                final List<External> externals = new ArrayList<External>(); // store discovered externals to here
                //EDIT next line removed by piascikj for building specific revision
                //final SVNRevision revision = SVNRevision.create(timestamp);
                //EDIT (3) next 6 lines added by piascikj for building specific revision
                SVNRevision revision = SVNRevision.create(timestamp);
                try {
                	if (this.revision != null) revision = SVNRevision.create(Long.parseLong(this.revision));
                } catch (NumberFormatException e) {
                	listener.getLogger().println("Unable to parse revision number from value: " + this.revision + ", checking out HEAD revision.");
                }
                if(update) {
                    for (final ModuleLocation l : locations) {
                        try {
                            listener.getLogger().println("Updating "+ l.remote);

                            File local = new File(ws, l.local);
                            svnuc.setEventHandler(new SubversionUpdateEventHandler(listener.getLogger(), externals,local,l.local));
                            svnuc.doUpdate(local.getCanonicalFile(), l.getRevision(revision), true);

                        } catch (final SVNException e) {
                            if(e.getErrorMessage().getErrorCode()== SVNErrorCode.WC_LOCKED) {
                                // work space locked. try fresh check out
                                listener.getLogger().println("Workspace appear to be locked, so getting a fresh workspace");
                                update = false;
                                return invoke(ws,channel);
                            }
                            if(e.getErrorMessage().getErrorCode()== SVNErrorCode.WC_OBSTRUCTED_UPDATE) {
                                // HUDSON-1882. If existence of local files cause an update to fail,
                                // revert to fresh check out
                                listener.getLogger().println(e.getMessage()); // show why this happened. Sometimes this is caused by having a build artifact in the repository.
                                listener.getLogger().println("Updated failed due to local files. Getting a fresh workspace");
                                update = false;
                                return invoke(ws,channel);
                            }

                            e.printStackTrace(listener.error("Failed to update "+l.remote));
                            // trouble-shooting probe for #591
                            if(e.getErrorMessage().getErrorCode()== SVNErrorCode.WC_NOT_LOCKED) {
                                listener.getLogger().println("Polled jobs are "+ Hudson.getInstance().getDescriptorByType(SCMTrigger.DescriptorImpl.class).getItemsBeingPolled());
                            }
                            return null;
                        }
                    }
                } else {
                    Util.deleteContentsRecursive(ws);

                    // buffer the output by a separate thread so that the update operation
                    // won't be blocked by the remoting of the data
                    PipedOutputStream pos = new PipedOutputStream();
                    StreamCopyThread sct = new StreamCopyThread("svn log copier", new PipedInputStream(pos), listener.getLogger());
                    sct.start();

                    for (final ModuleLocation l : locations) {
                        try {
                            listener.getLogger().println("Checking out "+l.remote);

                            File local = new File(ws, l.local);
                            svnuc.setEventHandler(new SubversionUpdateEventHandler(new PrintStream(pos), externals, local, l.local));
                            svnuc.doCheckout(l.getSVNURL(), local.getCanonicalFile(), SVNRevision.HEAD, l.getRevision(revision), true);
                        } catch (SVNException e) {
                            e.printStackTrace(listener.error("Failed to check out "+l.remote));
                            return null;
                        }
                    }

                    pos.close();
                    try {
						sct.join(); // wait for all data to be piped.
					} catch (InterruptedException e) {
                        throw new IOException2("interrupted",e);
                    }
                }

                try {
                    for (final ModuleLocation l : locations) {
                        SVNDirEntry dir = manager.createRepository(l.getSVNURL(),true).info("/",-1);
                        if(dir!=null) {// I don't think this can ever be null, but be defensive
                            if(dir.getDate()!=null && dir.getDate().after(new Date())) // see http://www.nabble.com/NullPointerException-in-SVN-Checkout-Update-td21609781.html that reported this being null.
                                listener.getLogger().println(Messages.SubversionSCM_ClockOutOfSync());
                        }
                    }
                } catch (SVNException e) {
                    LOGGER.log(Level.INFO,"Failed to estimate the remote time stamp",e);
                }

                return externals;
            } finally {
                manager.dispose();
            }
        }

        private static final long serialVersionUID = 1L;
    }