/*
    * Copyright (C) 2008, Google Inc. and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.transport;
  
  import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
  import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON;
  
  import java.io.IOException;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import org.eclipse.jgit.annotations.NonNull;
  import org.eclipse.jgit.annotations.Nullable;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.AnyObjectId;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevObject;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /**
   * A command being processed by
   * {@link org.eclipse.jgit.transport.ReceivePack}.
   * <p>
   * This command instance roughly translates to the server side representation of
   * the {@link org.eclipse.jgit.transport.RemoteRefUpdate} created by the client.
   */
  public class ReceiveCommand {
  	/** Type of operation requested. */
  	public enum Type {
  		/** Create a new ref; the ref must not already exist. */
  		CREATE,
  
  		/**
  		 * Update an existing ref with a fast-forward update.
  		 * <p>
  		 * During a fast-forward update no changes will be lost; only new
  		 * commits are inserted into the ref.
  		 */
  		UPDATE,
  
  		/**
  		 * Update an existing ref by potentially discarding objects.
  		 * <p>
  		 * The current value of the ref is not fully reachable from the new
  		 * value of the ref, so a successful command may result in one or more
  		 * objects becoming unreachable.
  		 */
  		UPDATE_NONFASTFORWARD,
  
  		/** Delete an existing ref; the ref should already exist. */
  		DELETE;
  	}
  
  	/** Result of the update command. */
  	public enum Result {
  		/** The command has not yet been attempted by the server. */
  		NOT_ATTEMPTED,
  
  		/** The server is configured to deny creation of this ref. */
  		REJECTED_NOCREATE,
  
  		/** The server is configured to deny deletion of this ref. */
  		REJECTED_NODELETE,
  
  		/** The update is a non-fast-forward update and isn't permitted. */
  		REJECTED_NONFASTFORWARD,
  
  		/** The update affects <code>HEAD</code> and cannot be permitted. */
  		REJECTED_CURRENT_BRANCH,
  
  		/**
  		 * One or more objects aren't in the repository.
  		 * <p>
  		 * This is severe indication of either repository corruption on the
  		 * server side, or a bug in the client wherein the client did not supply
  		 * all required objects during the pack transfer.
  		 */
  		REJECTED_MISSING_OBJECT,
  
  		/** Other failure; see {@link ReceiveCommand#getMessage()}. */
  		REJECTED_OTHER_REASON,
  
  		/** The ref could not be locked and updated atomically; try again. */
  		LOCK_FAILURE,
  
  		/** The change was completed successfully. */
 		OK;
 	}
 
 	/**
 	 * Filter a collection of commands according to result.
 	 *
 	 * @param in
 	 *            commands to filter.
 	 * @param want
 	 *            desired status to filter by.
 	 * @return a copy of the command list containing only those commands with
 	 *         the desired status.
 	 * @since 4.2
 	 */
 	public static List<ReceiveCommand> filter(Iterable<ReceiveCommand> in,
 			Result want) {
 		List<ReceiveCommand> r;
 		if (in instanceof Collection)
 			r = new ArrayList<>(((Collection<?>) in).size());
 		else
 			r = new ArrayList<>();
 		for (ReceiveCommand cmd : in) {
 			if (cmd.getResult() == want)
 				r.add(cmd);
 		}
 		return r;
 	}
 
 	/**
 	 * Filter a list of commands according to result.
 	 *
 	 * @param commands
 	 *            commands to filter.
 	 * @param want
 	 *            desired status to filter by.
 	 * @return a copy of the command list containing only those commands with
 	 *         the desired status.
 	 * @since 2.0
 	 */
 	public static List<ReceiveCommand> filter(List<ReceiveCommand> commands,
 			Result want) {
 		return filter((Iterable<ReceiveCommand>) commands, want);
 	}
 
 	/**
 	 * Set unprocessed commands as failed due to transaction aborted.
 	 * <p>
 	 * If a command is still
 	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#NOT_ATTEMPTED} it
 	 * will be set to
 	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#REJECTED_OTHER_REASON}.
 	 *
 	 * @param commands
 	 *            commands to mark as failed.
 	 * @since 4.2
 	 */
 	public static void abort(Iterable<ReceiveCommand> commands) {
 		for (ReceiveCommand c : commands) {
 			if (c.getResult() == NOT_ATTEMPTED) {
 				c.setResult(REJECTED_OTHER_REASON,
 						JGitText.get().transactionAborted);
 			}
 		}
 	}
 
 	/**
 	 * Check whether a command failed due to transaction aborted.
 	 *
 	 * @param cmd
 	 *            command.
 	 * @return whether the command failed due to transaction aborted, as in
 	 *         {@link #abort(Iterable)}.
 	 * @since 4.9
 	 */
 	public static boolean isTransactionAborted(ReceiveCommand cmd) {
 		return cmd.getResult() == REJECTED_OTHER_REASON
 				&& cmd.getMessage().equals(JGitText.get().transactionAborted);
 	}
 
 	/**
 	 * Create a command to switch a reference from object to symbolic.
 	 *
 	 * @param oldId
 	 *            expected oldId. May be {@code zeroId} to create.
 	 * @param newTarget
 	 *            new target; must begin with {@code "refs/"}.
 	 * @param name
 	 *            name of the reference to make symbolic.
 	 * @return command instance.
 	 * @since 4.10
 	 */
 	public static ReceiveCommand link(@NonNull ObjectId oldId,
 			@NonNull String newTarget, @NonNull String name) {
 		return new ReceiveCommand(oldId, newTarget, name);
 	}
 
 	/**
 	 * Create a command to switch a symbolic reference's target.
 	 *
 	 * @param oldTarget
 	 *            expected old target. May be null to create.
 	 * @param newTarget
 	 *            new target; must begin with {@code "refs/"}.
 	 * @param name
 	 *            name of the reference to make symbolic.
 	 * @return command instance.
 	 * @since 4.10
 	 */
 	public static ReceiveCommand link(@Nullable String oldTarget,
 			@NonNull String newTarget, @NonNull String name) {
 		return new ReceiveCommand(oldTarget, newTarget, name);
 	}
 
 	/**
 	 * Create a command to switch a reference from symbolic to object.
 	 *
 	 * @param oldTarget
 	 *            expected old target.
 	 * @param newId
 	 *            new object identifier. May be {@code zeroId()} to delete.
 	 * @param name
 	 *            name of the reference to convert from symbolic.
 	 * @return command instance.
 	 * @since 4.10
 	 */
 	public static ReceiveCommand unlink(@NonNull String oldTarget,
 			@NonNull ObjectId newId, @NonNull String name) {
 		return new ReceiveCommand(oldTarget, newId, name);
 	}
 
 	private final ObjectId oldId;
 
 	private final String oldSymref;
 
 	private final ObjectId newId;
 
 	private final String newSymref;
 
 	private final String name;
 
 	private Type type;
 
 	private boolean typeIsCorrect;
 
 	private Ref ref;
 
 	private Result status = Result.NOT_ATTEMPTED;
 
 	private String message;
 
 	private boolean customRefLog;
 
 	private String refLogMessage;
 
 	private boolean refLogIncludeResult;
 
 	private Boolean forceRefLog;
 
 	/**
 	 * Create a new command for
 	 * {@link org.eclipse.jgit.transport.ReceivePack}.
 	 *
 	 * @param oldId
 	 *            the expected old object id; must not be null. Use
 	 *            {@link org.eclipse.jgit.lib.ObjectId#zeroId()} to indicate a
 	 *            ref creation.
 	 * @param newId
 	 *            the new object id; must not be null. Use
 	 *            {@link org.eclipse.jgit.lib.ObjectId#zeroId()} to indicate a
 	 *            ref deletion.
 	 * @param name
 	 *            name of the ref being affected.
 	 */
 	public ReceiveCommand(final ObjectId oldId, final ObjectId newId,
 			final String name) {
 		if (oldId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().oldIdMustNotBeNull);
 		}
 		if (newId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().newIdMustNotBeNull);
 		}
 		if (name == null || name.isEmpty()) {
 			throw new IllegalArgumentException(
 					JGitText.get().nameMustNotBeNullOrEmpty);
 		}
 		this.oldId = oldId;
 		this.oldSymref = null;
 		this.newId = newId;
 		this.newSymref = null;
 		this.name = name;
 
 		type = Type.UPDATE;
 		if (ObjectId.zeroId().equals(oldId)) {
 			type = Type.CREATE;
 		}
 		if (ObjectId.zeroId().equals(newId)) {
 			type = Type.DELETE;
 		}
 	}
 
 	/**
 	 * Create a new command for
 	 * {@link org.eclipse.jgit.transport.ReceivePack}.
 	 *
 	 * @param oldId
 	 *            the old object id; must not be null. Use
 	 *            {@link org.eclipse.jgit.lib.ObjectId#zeroId()} to indicate a
 	 *            ref creation.
 	 * @param newId
 	 *            the new object id; must not be null. Use
 	 *            {@link org.eclipse.jgit.lib.ObjectId#zeroId()} to indicate a
 	 *            ref deletion.
 	 * @param name
 	 *            name of the ref being affected.
 	 * @param type
 	 *            type of the command. Must be
 	 *            {@link org.eclipse.jgit.transport.ReceiveCommand.Type#CREATE}
 	 *            if {@code
 	 *            oldId} is zero, or
 	 *            {@link org.eclipse.jgit.transport.ReceiveCommand.Type#DELETE}
 	 *            if {@code newId} is zero.
 	 * @since 2.0
 	 */
 	public ReceiveCommand(final ObjectId oldId, final ObjectId newId,
 			final String name, final Type type) {
 		if (oldId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().oldIdMustNotBeNull);
 		}
 		if (newId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().newIdMustNotBeNull);
 		}
 		if (name == null || name.isEmpty()) {
 			throw new IllegalArgumentException(
 					JGitText.get().nameMustNotBeNullOrEmpty);
 		}
 		this.oldId = oldId;
 		this.oldSymref = null;
 		this.newId = newId;
 		this.newSymref = null;
 		this.name = name;
 		switch (type) {
 		case CREATE:
 			if (!ObjectId.zeroId().equals(oldId)) {
 				throw new IllegalArgumentException(
 						JGitText.get().createRequiresZeroOldId);
 			}
 			break;
 		case DELETE:
 			if (!ObjectId.zeroId().equals(newId)) {
 				throw new IllegalArgumentException(
 						JGitText.get().deleteRequiresZeroNewId);
 			}
 			break;
 		case UPDATE:
 		case UPDATE_NONFASTFORWARD:
 			if (ObjectId.zeroId().equals(newId)
 					|| ObjectId.zeroId().equals(oldId)) {
 				throw new IllegalArgumentException(
 						JGitText.get().updateRequiresOldIdAndNewId);
 			}
 			break;
 		default:
 			throw new IllegalStateException(
 					JGitText.get().enumValueNotSupported0);
 		}
 		this.type = type;
 	}
 
 	/**
 	 * Create a command to switch a reference from object to symbolic.
 	 *
 	 * @param oldId
 	 *            the old object id; must not be null. Use
 	 *            {@link ObjectId#zeroId()} to indicate a ref creation.
 	 * @param newSymref
 	 *            new target, must begin with {@code "refs/"}. Use {@code null}
 	 *            to indicate a ref deletion.
 	 * @param name
 	 *            name of the reference to make symbolic.
 	 * @since 4.10
 	 */
 	private ReceiveCommand(ObjectId oldId, String newSymref, String name) {
 		if (oldId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().oldIdMustNotBeNull);
 		}
 		if (name == null || name.isEmpty()) {
 			throw new IllegalArgumentException(
 					JGitText.get().nameMustNotBeNullOrEmpty);
 		}
 		this.oldId = oldId;
 		this.oldSymref = null;
 		this.newId = ObjectId.zeroId();
 		this.newSymref = newSymref;
 		this.name = name;
 		if (AnyObjectId.isEqual(ObjectId.zeroId(), oldId)) {
 			type = Type.CREATE;
 		} else if (newSymref != null) {
 			type = Type.UPDATE;
 		} else {
 			type = Type.DELETE;
 		}
 		typeIsCorrect = true;
 	}
 
 	/**
 	 * Create a command to switch a reference from symbolic to object.
 	 *
 	 * @param oldSymref
 	 *            expected old target. Use {@code null} to indicate a ref
 	 *            creation.
 	 * @param newId
 	 *            the new object id; must not be null. Use
 	 *            {@link ObjectId#zeroId()} to indicate a ref deletion.
 	 * @param name
 	 *            name of the reference to convert from symbolic.
 	 * @since 4.10
 	 */
 	private ReceiveCommand(String oldSymref, ObjectId newId, String name) {
 		if (newId == null) {
 			throw new IllegalArgumentException(
 					JGitText.get().newIdMustNotBeNull);
 		}
 		if (name == null || name.isEmpty()) {
 			throw new IllegalArgumentException(
 					JGitText.get().nameMustNotBeNullOrEmpty);
 		}
 		this.oldId = ObjectId.zeroId();
 		this.oldSymref = oldSymref;
 		this.newId = newId;
 		this.newSymref = null;
 		this.name = name;
 		if (oldSymref == null) {
 			type = Type.CREATE;
 		} else if (!AnyObjectId.isEqual(ObjectId.zeroId(), newId)) {
 			type = Type.UPDATE;
 		} else {
 			type = Type.DELETE;
 		}
 		typeIsCorrect = true;
 	}
 
 	/**
 	 * Create a command to switch a symbolic reference's target.
 	 *
 	 * @param oldTarget
 	 *            expected old target. Use {@code null} to indicate a ref
 	 *            creation.
 	 * @param newTarget
 	 *            new target. Use {@code null} to indicate a ref deletion.
 	 * @param name
 	 *            name of the reference to make symbolic.
 	 * @since 4.10
 	 */
 	private ReceiveCommand(@Nullable String oldTarget, String newTarget, String name) {
 		if (name == null || name.isEmpty()) {
 			throw new IllegalArgumentException(
 					JGitText.get().nameMustNotBeNullOrEmpty);
 		}
 		this.oldId = ObjectId.zeroId();
 		this.oldSymref = oldTarget;
 		this.newId = ObjectId.zeroId();
 		this.newSymref = newTarget;
 		this.name = name;
 		if (oldTarget == null) {
 			if (newTarget == null) {
 				throw new IllegalArgumentException(
 						JGitText.get().bothRefTargetsMustNotBeNull);
 			}
 			type = Type.CREATE;
 		} else if (newTarget != null) {
 			type = Type.UPDATE;
 		} else {
 			type = Type.DELETE;
 		}
 		typeIsCorrect = true;
 	}
 
 	/**
 	 * Get the old value the client thinks the ref has.
 	 *
 	 * @return the old value the client thinks the ref has.
 	 */
 	public ObjectId getOldId() {
 		return oldId;
 	}
 
 	/**
 	 * Get expected old target for a symbolic reference.
 	 *
 	 * @return expected old target for a symbolic reference.
 	 * @since 4.10
 	 */
 	@Nullable
 	public String getOldSymref() {
 		return oldSymref;
 	}
 
 	/**
 	 * Get the requested new value for this ref.
 	 *
 	 * @return the requested new value for this ref.
 	 */
 	public ObjectId getNewId() {
 		return newId;
 	}
 
 	/**
 	 * Get requested new target for a symbolic reference.
 	 *
 	 * @return requested new target for a symbolic reference.
 	 * @since 4.10
 	 */
 	@Nullable
 	public String getNewSymref() {
 		return newSymref;
 	}
 
 	/**
 	 * Get the name of the ref being updated.
 	 *
 	 * @return the name of the ref being updated.
 	 */
 	public String getRefName() {
 		return name;
 	}
 
 	/**
 	 * Get the type of this command; see {@link Type}.
 	 *
 	 * @return the type of this command; see {@link Type}.
 	 */
 	public Type getType() {
 		return type;
 	}
 
 	/**
 	 * Get the ref, if this was advertised by the connection.
 	 *
 	 * @return the ref, if this was advertised by the connection.
 	 */
 	public Ref getRef() {
 		return ref;
 	}
 
 	/**
 	 * Get the current status code of this command.
 	 *
 	 * @return the current status code of this command.
 	 */
 	public Result getResult() {
 		return status;
 	}
 
 	/**
 	 * Get the message associated with a failure status.
 	 *
 	 * @return the message associated with a failure status.
 	 */
 	public String getMessage() {
 		return message;
 	}
 
 	/**
 	 * Set the message to include in the reflog.
 	 * <p>
 	 * Overrides the default set by {@code setRefLogMessage} on any containing
 	 * {@link org.eclipse.jgit.lib.BatchRefUpdate}.
 	 *
 	 * @param msg
 	 *            the message to describe this change. If null and appendStatus is
 	 *            false, the reflog will not be updated.
 	 * @param appendStatus
 	 *            true if the status of the ref change (fast-forward or
 	 *            forced-update) should be appended to the user supplied message.
 	 * @since 4.9
 	 */
 	public void setRefLogMessage(String msg, boolean appendStatus) {
 		customRefLog = true;
 		if (msg == null && !appendStatus) {
 			disableRefLog();
 		} else if (msg == null && appendStatus) {
 			refLogMessage = ""; //$NON-NLS-1$
 			refLogIncludeResult = true;
 		} else {
 			refLogMessage = msg;
 			refLogIncludeResult = appendStatus;
 		}
 	}
 
 	/**
 	 * Don't record this update in the ref's associated reflog.
 	 * <p>
 	 * Equivalent to {@code setRefLogMessage(null, false)}.
 	 *
 	 * @since 4.9
 	 */
 	public void disableRefLog() {
 		customRefLog = true;
 		refLogMessage = null;
 		refLogIncludeResult = false;
 	}
 
 	/**
 	 * Force writing a reflog for the updated ref.
 	 *
 	 * @param force whether to force.
 	 * @since 4.9
 	 */
 	public void setForceRefLog(boolean force) {
 		forceRefLog = Boolean.valueOf(force);
 	}
 
 	/**
 	 * Check whether this command has a custom reflog message setting that should
 	 * override defaults in any containing
 	 * {@link org.eclipse.jgit.lib.BatchRefUpdate}.
 	 * <p>
 	 * Does not take into account whether {@code #setForceRefLog(boolean)} has
 	 * been called.
 	 *
 	 * @return whether a custom reflog is set.
 	 * @since 4.9
 	 */
 	public boolean hasCustomRefLog() {
 		return customRefLog;
 	}
 
 	/**
 	 * Check whether log has been disabled by {@link #disableRefLog()}.
 	 *
 	 * @return true if disabled.
 	 * @since 4.9
 	 */
 	public boolean isRefLogDisabled() {
 		return refLogMessage == null;
 	}
 
 	/**
 	 * Get the message to include in the reflog.
 	 *
 	 * @return message the caller wants to include in the reflog; null if the
 	 *         update should not be logged.
 	 * @since 4.9
 	 */
 	@Nullable
 	public String getRefLogMessage() {
 		return refLogMessage;
 	}
 
 	/**
 	 * Check whether the reflog message should include the result of the update,
 	 * such as fast-forward or force-update.
 	 *
 	 * @return true if the message should include the result.
 	 * @since 4.9
 	 */
 	public boolean isRefLogIncludingResult() {
 		return refLogIncludeResult;
 	}
 
 	/**
 	 * Check whether the reflog should be written regardless of repo defaults.
 	 *
 	 * @return whether force writing is enabled; {@code null} if
 	 *         {@code #setForceRefLog(boolean)} was never called.
 	 * @since 4.9
 	 */
 	@Nullable
 	public Boolean isForceRefLog() {
 		return forceRefLog;
 	}
 
 	/**
 	 * Set the status of this command.
 	 *
 	 * @param s
 	 *            the new status code for this command.
 	 */
 	public void setResult(Result s) {
 		setResult(s, null);
 	}
 
 	/**
 	 * Set the status of this command.
 	 *
 	 * @param s
 	 *            new status code for this command.
 	 * @param m
 	 *            optional message explaining the new status.
 	 */
 	public void setResult(Result s, String m) {
 		status = s;
 		message = m;
 	}
 
 	/**
 	 * Update the type of this command by checking for fast-forward.
 	 * <p>
 	 * If the command's current type is UPDATE, a merge test will be performed
 	 * using the supplied RevWalk to determine if {@link #getOldId()} is fully
 	 * merged into {@link #getNewId()}. If some commits are not merged the
 	 * update type is changed to
 	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Type#UPDATE_NONFASTFORWARD}.
 	 *
 	 * @param walk
 	 *            an instance to perform the merge test with. The caller must
 	 *            allocate and release this object.
 	 * @throws java.io.IOException
 	 *             either oldId or newId is not accessible in the repository
 	 *             used by the RevWalk. This usually indicates data corruption,
 	 *             and the command cannot be processed.
 	 */
 	public void updateType(RevWalk walk) throws IOException {
 		if (typeIsCorrect)
 			return;
 		if (type == Type.UPDATE && !AnyObjectId.isEqual(oldId, newId)) {
 			RevObject o = walk.parseAny(oldId);
 			RevObject n = walk.parseAny(newId);
 			if (!(o instanceof RevCommit)
 					|| !(n instanceof RevCommit)
 					|| !walk.isMergedInto((RevCommit) o, (RevCommit) n))
 				setType(Type.UPDATE_NONFASTFORWARD);
 		}
 		typeIsCorrect = true;
 	}
 
 	/**
 	 * Execute this command during a receive-pack session.
 	 * <p>
 	 * Sets the status of the command as a side effect.
 	 *
 	 * @param rp
 	 *            receive-pack session.
 	 * @since 5.6
 	 */
 	public void execute(ReceivePack rp) {
 		try {
 			String expTarget = getOldSymref();
 			boolean detach = getNewSymref() != null
 					|| (type == Type.DELETE && expTarget != null);
 			RefUpdate ru = rp.getRepository().updateRef(getRefName(), detach);
 			if (expTarget != null) {
 				if (!ru.getRef().isSymbolic() || !ru.getRef().getTarget()
 						.getName().equals(expTarget)) {
 					setResult(Result.LOCK_FAILURE);
 					return;
 				}
 			}
 
 			ru.setRefLogIdent(rp.getRefLogIdent());
 			ru.setRefLogMessage(refLogMessage, refLogIncludeResult);
 			switch (getType()) {
 			case DELETE:
 				if (!ObjectId.zeroId().equals(getOldId())) {
 					// We can only do a CAS style delete if the client
 					// didn't bork its delete request by sending the
 					// wrong zero id rather than the advertised one.
 					//
 					ru.setExpectedOldObjectId(getOldId());
 				}
 				ru.setForceUpdate(true);
 				setResult(ru.delete(rp.getRevWalk()));
 				break;
 
 			case CREATE:
 			case UPDATE:
 			case UPDATE_NONFASTFORWARD:
 				ru.setForceUpdate(rp.isAllowNonFastForwards());
 				ru.setExpectedOldObjectId(getOldId());
 				ru.setRefLogMessage("push", true); //$NON-NLS-1$
 				if (getNewSymref() != null) {
 					setResult(ru.link(getNewSymref()));
 				} else {
 					ru.setNewObjectId(getNewId());
 					setResult(ru.update(rp.getRevWalk()));
 				}
 				break;
 			}
 		} catch (IOException err) {
 			reject(err);
 		}
 	}
 
 	void setRef(Ref r) {
 		ref = r;
 	}
 
 	void setType(Type t) {
 		type = t;
 	}
 
 	void setTypeFastForwardUpdate() {
 		type = Type.UPDATE;
 		typeIsCorrect = true;
 	}
 
 	/**
 	 * Set the result of this command.
 	 *
 	 * @param r
 	 *            the new result code for this command.
 	 */
 	public void setResult(RefUpdate.Result r) {
 		switch (r) {
 		case NOT_ATTEMPTED:
 			setResult(Result.NOT_ATTEMPTED);
 			break;
 
 		case LOCK_FAILURE:
 		case IO_FAILURE:
 			setResult(Result.LOCK_FAILURE);
 			break;
 
 		case NO_CHANGE:
 		case NEW:
 		case FORCED:
 		case FAST_FORWARD:
 			setResult(Result.OK);
 			break;
 
 		case REJECTED:
 			setResult(Result.REJECTED_NONFASTFORWARD);
 			break;
 
 		case REJECTED_CURRENT_BRANCH:
 			setResult(Result.REJECTED_CURRENT_BRANCH);
 			break;
 
 		case REJECTED_MISSING_OBJECT:
 			setResult(Result.REJECTED_MISSING_OBJECT);
 			break;
 
 		case REJECTED_OTHER_REASON:
 			setResult(Result.REJECTED_OTHER_REASON);
 			break;
 
 		default:
 			setResult(Result.REJECTED_OTHER_REASON, r.name());
 			break;
 		}
 	}
 
 	void reject(IOException err) {
 		setResult(Result.REJECTED_OTHER_REASON, MessageFormat.format(
 				JGitText.get().lockError, err.getMessage()));
 	}
 
 	/** {@inheritDoc} */
 	@SuppressWarnings("nls")
 	@Override
 	public String toString() {
 		return getType().name() + ": " + getOldId().name() + " "
 				+ getNewId().name() + " " + getRefName();
 	}
 }