gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java - gerrit - Git at Google

 // Copyright (C) 2012 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package com.google.gerrit.server.git.validators;

 import com.google.gerrit.common.PageLinks;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.config.CanonicalWebUrl;
 import com.google.gerrit.server.events.CommitReceivedEvent;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.git.ProjectConfig;
 import com.google.gerrit.server.git.ValidationError;
 import com.google.gerrit.server.project.ProjectControl;
 import com.google.gerrit.server.project.RefControl;
 import com.google.gerrit.server.ssh.SshInfo;
 import com.google.gerrit.server.util.MagicBranch;
 import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;

 import com.jcraft.jsch.HostKey;

 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.FooterKey;
 import org.eclipse.jgit.revwalk.FooterLine;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.util.SystemReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.regex.Pattern;

 import javax.annotation.Nullable;

 public class CommitValidators {
   private static final Logger log = LoggerFactory
       .getLogger(CommitValidators.class);

   private static final FooterKey CHANGE_ID = new FooterKey("Change-Id");

   private static final Pattern NEW_PATCHSET = Pattern
       .compile("^refs/changes/(?:[0-9][0-9])?(/[1-9][0-9]*){1,2}(?:/new)?$");

   public interface Factory {
     CommitValidators create(RefControl refControl, SshInfo sshInfo,
         Repository repo);
   }

   private final PersonIdent gerritIdent;
   private final RefControl refControl;
   private final String canonicalWebUrl;
   private final SshInfo sshInfo;
   private final Repository repo;
   private final DynamicSet<CommitValidationListener> commitValidationListeners;

   @Inject
   CommitValidators(@GerritPersonIdent final PersonIdent gerritIdent,
       @CanonicalWebUrl @Nullable final String canonicalWebUrl,
       final DynamicSet<CommitValidationListener> commitValidationListeners,
       @Assisted final SshInfo sshInfo,
       @Assisted final Repository repo, @Assisted final RefControl refControl) {
     this.gerritIdent = gerritIdent;
     this.refControl = refControl;
     this.canonicalWebUrl = canonicalWebUrl;
     this.sshInfo = sshInfo;
     this.repo = repo;
     this.commitValidationListeners = commitValidationListeners;
   }

   public List<CommitValidationMessage> validateForReceiveCommits(
       CommitReceivedEvent receiveEvent) throws CommitValidationException {

     List<CommitValidationListener> validators =
         new LinkedList<CommitValidationListener>();

     validators.add(new UploadMergesPermissionValidator(refControl));
     validators.add(new AmendedGerritMergeCommitValidationListener(
         refControl, gerritIdent));
     validators.add(new AuthorUploaderValidator(refControl, canonicalWebUrl));
     validators.add(new CommitterUploaderValidator(refControl, canonicalWebUrl));
     validators.add(new SignedOffByValidator(refControl, canonicalWebUrl));
     if (MagicBranch.isMagicBranch(receiveEvent.command.getRefName())
         || NEW_PATCHSET.matcher(receiveEvent.command.getRefName()).matches()) {
       validators.add(new ChangeIdValidator(refControl, canonicalWebUrl, sshInfo));
     }
     validators.add(new ConfigValidator(refControl, repo));
     validators.add(new PluginCommitValidationListener(commitValidationListeners));

     List<CommitValidationMessage> messages =
         new LinkedList<CommitValidationMessage>();

     try {
       for (CommitValidationListener commitValidator : validators) {
         messages.addAll(commitValidator.onCommitReceived(receiveEvent));
       }
     } catch (CommitValidationException e) {
       // Keep the old messages (and their order) in case of an exception
       messages.addAll(e.getMessages());
       throw new CommitValidationException(e.getMessage(), messages);
     }
     return messages;
   }

   public List<CommitValidationMessage> validateForGerritCommits(
       CommitReceivedEvent receiveEvent) throws CommitValidationException {

     List<CommitValidationListener> validators =
         new LinkedList<CommitValidationListener>();

     validators.add(new UploadMergesPermissionValidator(refControl));
     validators.add(new AmendedGerritMergeCommitValidationListener(
         refControl, gerritIdent));
     validators.add(new AuthorUploaderValidator(refControl, canonicalWebUrl));
     validators.add(new SignedOffByValidator(refControl, canonicalWebUrl));
     if (MagicBranch.isMagicBranch(receiveEvent.command.getRefName())
         || NEW_PATCHSET.matcher(receiveEvent.command.getRefName()).matches()) {
       validators.add(new ChangeIdValidator(refControl, canonicalWebUrl, sshInfo));
     }
     validators.add(new ConfigValidator(refControl, repo));
     validators.add(new PluginCommitValidationListener(commitValidationListeners));

     List<CommitValidationMessage> messages =
         new LinkedList<CommitValidationMessage>();

     try {
       for (CommitValidationListener commitValidator : validators) {
         messages.addAll(commitValidator.onCommitReceived(receiveEvent));
       }
     } catch (CommitValidationException e) {
       // Keep the old messages (and their order) in case of an exception
       messages.addAll(e.getMessages());
       throw new CommitValidationException(e.getMessage(), messages);
     }
     return messages;
   }

   public static class ChangeIdValidator implements CommitValidationListener {
     private final RefControl refControl;
     private final String canonicalWebUrl;
     private final SshInfo sshInfo;

     public ChangeIdValidator(RefControl refControl, String canonicalWebUrl,
         SshInfo sshInfo) {
       this.refControl = refControl;
       this.canonicalWebUrl = canonicalWebUrl;
       this.sshInfo = sshInfo;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {

       final ProjectControl projectControl = refControl.getProjectControl();
       IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
       final List<String> idList = receiveEvent.commit.getFooterLines(CHANGE_ID);

       List<CommitValidationMessage> messages =
           new LinkedList<CommitValidationMessage>();

       if (idList.isEmpty()) {
         if (projectControl.getProjectState().isRequireChangeID()) {
           String errMsg = "missing Change-Id in commit message footer";
           messages.add(getFixedCommitMsgWithChangeId(errMsg, receiveEvent.commit,
               currentUser, canonicalWebUrl, sshInfo));
           throw new CommitValidationException(errMsg, messages);
         }
       } else if (idList.size() > 1) {
         throw new CommitValidationException(
             "multiple Change-Id lines in commit message footer", messages);
       } else {
         final String v = idList.get(idList.size() - 1).trim();
         if (!v.matches("^I[0-9a-f]{8,}.*$")) {
           final String errMsg =
               "missing or invalid Change-Id line format in commit message footer";
           messages.add(getFixedCommitMsgWithChangeId(errMsg, receiveEvent.commit,
               currentUser, canonicalWebUrl, sshInfo));
           throw new CommitValidationException(errMsg, messages);
         }
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /**
    * If this is the special project configuration branch, validate the config.
    */
   public static class ConfigValidator implements CommitValidationListener {
     private final RefControl refControl;
     private final Repository repo;

     public ConfigValidator(RefControl refControl, Repository repo) {
       this.refControl = refControl;
       this.repo = repo;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();

       if (GitRepositoryManager.REF_CONFIG.equals(refControl.getRefName())) {
         List<CommitValidationMessage> messages =
             new LinkedList<CommitValidationMessage>();

         try {
           ProjectConfig cfg =
               new ProjectConfig(receiveEvent.project.getNameKey());
           cfg.load(repo, receiveEvent.command.getNewId());
           if (!cfg.getValidationErrors().isEmpty()) {
             addError("Invalid project configuration:", messages);
             for (ValidationError err : cfg.getValidationErrors()) {
               addError("  " + err.getMessage(), messages);
             }
             throw new ConfigInvalidException("invalid project configuration");
           }
         } catch (Exception e) {
           log.error("User " + currentUser.getUserName()
               + " tried to push invalid project configuration "
               + receiveEvent.command.getNewId().name() + " for "
               + receiveEvent.project.getName(), e);
           throw new CommitValidationException("invalid project configuration",
               messages);
         }
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /** Require permission to upload merges. */
   public static class UploadMergesPermissionValidator implements
       CommitValidationListener {
     private final RefControl refControl;

     public UploadMergesPermissionValidator(RefControl refControl) {
       this.refControl = refControl;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       if (receiveEvent.commit.getParentCount() > 1
           && !refControl.canUploadMerges()) {
         throw new CommitValidationException("you are not allowed to upload merges");
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /** Execute commit validation plug-ins */
   public static class PluginCommitValidationListener implements
       CommitValidationListener {
     private final DynamicSet<CommitValidationListener> commitValidationListeners;

     public PluginCommitValidationListener(
         final DynamicSet<CommitValidationListener> commitValidationListeners) {
       this.commitValidationListeners = commitValidationListeners;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       List<CommitValidationMessage> messages =
           new LinkedList<CommitValidationMessage>();

       for (CommitValidationListener validator : commitValidationListeners) {
         try {
           messages.addAll(validator.onCommitReceived(receiveEvent));
         } catch (CommitValidationException e) {
           messages.addAll(e.getMessages());
           throw new CommitValidationException(e.getMessage(), messages);
         }
       }
       return messages;
     }
   }

   public static class SignedOffByValidator implements CommitValidationListener {
     private final RefControl refControl;

     public SignedOffByValidator(RefControl refControl, String canonicalWebUrl) {
       this.refControl = refControl;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
       final PersonIdent committer = receiveEvent.commit.getCommitterIdent();
       final PersonIdent author = receiveEvent.commit.getAuthorIdent();
       final ProjectControl projectControl = refControl.getProjectControl();

       if (projectControl.getProjectState().isUseSignedOffBy()) {
         boolean sboAuthor = false, sboCommitter = false, sboMe = false;
         for (final FooterLine footer : receiveEvent.commit.getFooterLines()) {
           if (footer.matches(FooterKey.SIGNED_OFF_BY)) {
             final String e = footer.getEmailAddress();
             if (e != null) {
               sboAuthor |= author.getEmailAddress().equals(e);
               sboCommitter |= committer.getEmailAddress().equals(e);
               sboMe |= currentUser.getEmailAddresses().contains(e);
             }
           }
         }
         if (!sboAuthor && !sboCommitter && !sboMe
             && !refControl.canForgeCommitter()) {
           throw new CommitValidationException(
               "not Signed-off-by author/committer/uploader in commit message footer");
         }
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /** Require that author matches the uploader. */
   public static class AuthorUploaderValidator implements
       CommitValidationListener {
     private final RefControl refControl;
     private final String canonicalWebUrl;

     public AuthorUploaderValidator(RefControl refControl, String canonicalWebUrl) {
       this.refControl = refControl;
       this.canonicalWebUrl = canonicalWebUrl;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
       final PersonIdent author = receiveEvent.commit.getAuthorIdent();

       if (!currentUser.getEmailAddresses().contains(author.getEmailAddress())
           && !refControl.canForgeAuthor()) {
         List<CommitValidationMessage> messages =
             new LinkedList<CommitValidationMessage>();

         messages.add(getInvalidEmailError(receiveEvent.commit, "author", author,
             currentUser, canonicalWebUrl));
         throw new CommitValidationException("invalid author", messages);
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /** Require that committer matches the uploader. */
   public static class CommitterUploaderValidator implements
       CommitValidationListener {
     private final RefControl refControl;
     private final String canonicalWebUrl;

     public CommitterUploaderValidator(RefControl refControl,
         String canonicalWebUrl) {
       this.refControl = refControl;
       this.canonicalWebUrl = canonicalWebUrl;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
       final PersonIdent committer = receiveEvent.commit.getCommitterIdent();
       if (!currentUser.getEmailAddresses()
           .contains(committer.getEmailAddress())
           && !refControl.canForgeCommitter()) {
         List<CommitValidationMessage> messages =
             new LinkedList<CommitValidationMessage>();
         messages.add(getInvalidEmailError(receiveEvent.commit, "committer", committer,
             currentUser, canonicalWebUrl));
         throw new CommitValidationException("invalid committer", messages);
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   /**
    * Don't allow the user to amend a merge created by Gerrit Code Review. This
    * seems to happen all too often, due to users not paying any attention to
    * what they are doing.
    */
   public static class AmendedGerritMergeCommitValidationListener implements
       CommitValidationListener {
     private final PersonIdent gerritIdent;
     private final RefControl refControl;

     public AmendedGerritMergeCommitValidationListener(
         final RefControl refControl, final PersonIdent gerritIdent) {
       this.refControl = refControl;
       this.gerritIdent = gerritIdent;
     }

     @Override
     public List<CommitValidationMessage> onCommitReceived(
         CommitReceivedEvent receiveEvent) throws CommitValidationException {
       final PersonIdent author = receiveEvent.commit.getAuthorIdent();

       if (receiveEvent.commit.getParentCount() > 1
           && author.getName().equals(gerritIdent.getName())
           && author.getEmailAddress().equals(gerritIdent.getEmailAddress())
           && !refControl.canForgeGerritServerIdentity()) {
         throw new CommitValidationException("do not amend merges not made by you");
       }
       return Collections.<CommitValidationMessage>emptyList();
     }
   }

   private static CommitValidationMessage getInvalidEmailError(RevCommit c, String type,
       PersonIdent who, IdentifiedUser currentUser, String canonicalWebUrl) {
     StringBuilder sb = new StringBuilder();
     sb.append("\n");
     sb.append("ERROR:  In commit " + c.name() + "\n");
     sb.append("ERROR:  " + type + " email address " + who.getEmailAddress()
         + "\n");
     sb.append("ERROR:  does not match your user account.\n");
     sb.append("ERROR:\n");
     if (currentUser.getEmailAddresses().isEmpty()) {
       sb.append("ERROR:  You have not registered any email addresses.\n");
     } else {
       sb.append("ERROR:  The following addresses are currently registered:\n");
       for (String address : currentUser.getEmailAddresses()) {
         sb.append("ERROR:    " + address + "\n");
       }
     }
     sb.append("ERROR:\n");
     if (canonicalWebUrl != null) {
       sb.append("ERROR:  To register an email address, please visit:\n");
       sb.append("ERROR:  " + canonicalWebUrl + "#" + PageLinks.SETTINGS_CONTACT
           + "\n");
     }
     sb.append("\n");
     return new CommitValidationMessage(sb.toString(), false);
   }

   /**
    * We handle 3 cases:
    * 1. No change id in the commit message at all.
    * 2. Change id last in the commit message but missing empty line to create the footer.
    * 3. There is a change-id somewhere in the commit message, but we ignore it.
    *
    * @return The fixed up commit message
    */
   private static CommitValidationMessage getFixedCommitMsgWithChangeId(final String errMsg,
       final RevCommit c, final IdentifiedUser currentUser,
       String canonicalWebUrl, final SshInfo sshInfo) {
     final String changeId = "Change-Id:";
     StringBuilder sb = new StringBuilder();
     sb.append("ERROR: ").append(errMsg);
     sb.append('\n');
     sb.append("Suggestion for commit message:\n");

     if (c.getFullMessage().indexOf(changeId) == -1) {
       sb.append(c.getFullMessage());
       sb.append('\n');
       sb.append(changeId).append(" I").append(c.name());
     } else {
       String lines[] = c.getFullMessage().trim().split("\n");
       String lastLine = lines.length > 0 ? lines[lines.length - 1] : "";

       if (lastLine.indexOf(changeId) == 0) {
         for (int i = 0; i < lines.length - 1; i++) {
           sb.append(lines[i]);
           sb.append('\n');
         }

         sb.append('\n');
         sb.append(lastLine);
       } else {
         sb.append(c.getFullMessage());
         sb.append('\n');
         sb.append(changeId).append(" I").append(c.name());
         sb.append('\n');
         sb.append("Hint: A potential Change-Id was found, but it was not in the ");
         sb.append("footer (last paragraph) of the commit message.");
       }
     }
     sb.append('\n');
     sb.append('\n');
     sb.append("Hint: To automatically insert Change-Id, install the hook:\n");
     sb.append(getCommitMessageHookInstallationHint(currentUser,
         canonicalWebUrl, sshInfo)).append('\n');
     sb.append('\n');

     return new CommitValidationMessage(sb.toString(), false);
   }

   private static String getCommitMessageHookInstallationHint(
       final IdentifiedUser currentUser, String canonicalWebUrl,
       final SshInfo sshInfo) {
     final List<HostKey> hostKeys = sshInfo.getHostKeys();

     // If there are no SSH keys, the commit-msg hook must be installed via
     // HTTP(S)
     if (hostKeys.isEmpty()) {
       String p = ".git/hooks/commit-msg";
       return String.format(
           "  curl -o %s %s/tools/hooks/commit-msg ; chmod +x %s", p,
           getGerritUrl(canonicalWebUrl), p);
     }

     // SSH keys exist, so the hook can be installed with scp.
     String sshHost;
     int sshPort;
     String host = hostKeys.get(0).getHost();
     int c = host.lastIndexOf(':');
     if (0 <= c) {
       if (host.startsWith("*:")) {
         sshHost = getGerritHost(canonicalWebUrl);
       } else {
         sshHost = host.substring(0, c);
       }
       sshPort = Integer.parseInt(host.substring(c + 1));
     } else {
       sshHost = host;
       sshPort = 22;
     }

     return String.format("  scp -p -P %d %s@%s:hooks/commit-msg .git/hooks/",
         sshPort, currentUser.getUserName(), sshHost);
   }

   /**
    * Get the Gerrit URL.
    *
    * @return the canonical URL (with any trailing slash removed) if it is
    *         configured, otherwise fall back to "http://hostname" where hostname
    *         is the value returned by {@link #getGerritHost()}.
    */
   private static String getGerritUrl(String canonicalWebUrl) {
     if (canonicalWebUrl != null) {
       if (canonicalWebUrl.endsWith("/")) {
         return canonicalWebUrl.substring(0, canonicalWebUrl.lastIndexOf("/"));
       }
       return canonicalWebUrl;
     } else {
       return "http://" + getGerritHost(canonicalWebUrl);
     }
   }

   /**
    * Get the Gerrit hostname.
    *
    * @return the hostname from the canonical URL if it is configured, otherwise
    *         whatever the OS says the hostname is.
    */
   private static String getGerritHost(String canonicalWebUrl) {
     String host;
     if (canonicalWebUrl != null) {
       try {
         host = new URL(canonicalWebUrl).getHost();
       } catch (MalformedURLException e) {
         host = SystemReader.getInstance().getHostname();
       }
     } else {
       host = SystemReader.getInstance().getHostname();
     }
     return host;
   }

   private static void addError(String error,
       List<CommitValidationMessage> messages) {
     messages.add(new CommitValidationMessage(error, true));
   }
 }
	// Copyright (C) 2012 The Android Open Source Project
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package com.google.gerrit.server.git.validators;

	import com.google.gerrit.common.PageLinks;
	import com.google.gerrit.extensions.registration.DynamicSet;
	import com.google.gerrit.server.GerritPersonIdent;
	import com.google.gerrit.server.IdentifiedUser;
	import com.google.gerrit.server.config.CanonicalWebUrl;
	import com.google.gerrit.server.events.CommitReceivedEvent;
	import com.google.gerrit.server.git.GitRepositoryManager;
	import com.google.gerrit.server.git.ProjectConfig;
	import com.google.gerrit.server.git.ValidationError;
	import com.google.gerrit.server.project.ProjectControl;
	import com.google.gerrit.server.project.RefControl;
	import com.google.gerrit.server.ssh.SshInfo;
	import com.google.gerrit.server.util.MagicBranch;
	import com.google.inject.Inject;
	import com.google.inject.assistedinject.Assisted;

	import com.jcraft.jsch.HostKey;

	import org.eclipse.jgit.errors.ConfigInvalidException;
	import org.eclipse.jgit.lib.PersonIdent;
	import org.eclipse.jgit.lib.Repository;
	import org.eclipse.jgit.revwalk.FooterKey;
	import org.eclipse.jgit.revwalk.FooterLine;
	import org.eclipse.jgit.revwalk.RevCommit;
	import org.eclipse.jgit.util.SystemReader;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.Collections;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.regex.Pattern;

	import javax.annotation.Nullable;

	public class CommitValidators {
	private static final Logger log = LoggerFactory
	.getLogger(CommitValidators.class);

	private static final FooterKey CHANGE_ID = new FooterKey("Change-Id");

	private static final Pattern NEW_PATCHSET = Pattern
	.compile("^refs/changes/(?:[0-9][0-9])?(/[1-9][0-9]*){1,2}(?:/new)?$");

	public interface Factory {
	CommitValidators create(RefControl refControl, SshInfo sshInfo,
	Repository repo);
	}

	private final PersonIdent gerritIdent;
	private final RefControl refControl;
	private final String canonicalWebUrl;
	private final SshInfo sshInfo;
	private final Repository repo;
	private final DynamicSet<CommitValidationListener> commitValidationListeners;

	@Inject
	CommitValidators(@GerritPersonIdent final PersonIdent gerritIdent,
	@CanonicalWebUrl @Nullable final String canonicalWebUrl,
	final DynamicSet<CommitValidationListener> commitValidationListeners,
	@Assisted final SshInfo sshInfo,
	@Assisted final Repository repo, @Assisted final RefControl refControl) {
	this.gerritIdent = gerritIdent;
	this.refControl = refControl;
	this.canonicalWebUrl = canonicalWebUrl;
	this.sshInfo = sshInfo;
	this.repo = repo;
	this.commitValidationListeners = commitValidationListeners;
	}

	public List<CommitValidationMessage> validateForReceiveCommits(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {

	List<CommitValidationListener> validators =
	new LinkedList<CommitValidationListener>();

	validators.add(new UploadMergesPermissionValidator(refControl));
	validators.add(new AmendedGerritMergeCommitValidationListener(
	refControl, gerritIdent));
	validators.add(new AuthorUploaderValidator(refControl, canonicalWebUrl));
	validators.add(new CommitterUploaderValidator(refControl, canonicalWebUrl));
	validators.add(new SignedOffByValidator(refControl, canonicalWebUrl));
	if (MagicBranch.isMagicBranch(receiveEvent.command.getRefName())
	\|\| NEW_PATCHSET.matcher(receiveEvent.command.getRefName()).matches()) {
	validators.add(new ChangeIdValidator(refControl, canonicalWebUrl, sshInfo));
	}
	validators.add(new ConfigValidator(refControl, repo));
	validators.add(new PluginCommitValidationListener(commitValidationListeners));

	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	try {
	for (CommitValidationListener commitValidator : validators) {
	messages.addAll(commitValidator.onCommitReceived(receiveEvent));
	}
	} catch (CommitValidationException e) {
	// Keep the old messages (and their order) in case of an exception
	messages.addAll(e.getMessages());
	throw new CommitValidationException(e.getMessage(), messages);
	}
	return messages;
	}

	public List<CommitValidationMessage> validateForGerritCommits(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {

	List<CommitValidationListener> validators =
	new LinkedList<CommitValidationListener>();

	validators.add(new UploadMergesPermissionValidator(refControl));
	validators.add(new AmendedGerritMergeCommitValidationListener(
	refControl, gerritIdent));
	validators.add(new AuthorUploaderValidator(refControl, canonicalWebUrl));
	validators.add(new SignedOffByValidator(refControl, canonicalWebUrl));
	if (MagicBranch.isMagicBranch(receiveEvent.command.getRefName())
	\|\| NEW_PATCHSET.matcher(receiveEvent.command.getRefName()).matches()) {
	validators.add(new ChangeIdValidator(refControl, canonicalWebUrl, sshInfo));
	}
	validators.add(new ConfigValidator(refControl, repo));
	validators.add(new PluginCommitValidationListener(commitValidationListeners));

	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	try {
	for (CommitValidationListener commitValidator : validators) {
	messages.addAll(commitValidator.onCommitReceived(receiveEvent));
	}
	} catch (CommitValidationException e) {
	// Keep the old messages (and their order) in case of an exception
	messages.addAll(e.getMessages());
	throw new CommitValidationException(e.getMessage(), messages);
	}
	return messages;
	}

	public static class ChangeIdValidator implements CommitValidationListener {
	private final RefControl refControl;
	private final String canonicalWebUrl;
	private final SshInfo sshInfo;

	public ChangeIdValidator(RefControl refControl, String canonicalWebUrl,
	SshInfo sshInfo) {
	this.refControl = refControl;
	this.canonicalWebUrl = canonicalWebUrl;
	this.sshInfo = sshInfo;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {

	final ProjectControl projectControl = refControl.getProjectControl();
	IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
	final List<String> idList = receiveEvent.commit.getFooterLines(CHANGE_ID);

	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	if (idList.isEmpty()) {
	if (projectControl.getProjectState().isRequireChangeID()) {
	String errMsg = "missing Change-Id in commit message footer";
	messages.add(getFixedCommitMsgWithChangeId(errMsg, receiveEvent.commit,
	currentUser, canonicalWebUrl, sshInfo));
	throw new CommitValidationException(errMsg, messages);
	}
	} else if (idList.size() > 1) {
	throw new CommitValidationException(
	"multiple Change-Id lines in commit message footer", messages);
	} else {
	final String v = idList.get(idList.size() - 1).trim();
	if (!v.matches("^I[0-9a-f]{8,}.*$")) {
	final String errMsg =
	"missing or invalid Change-Id line format in commit message footer";
	messages.add(getFixedCommitMsgWithChangeId(errMsg, receiveEvent.commit,
	currentUser, canonicalWebUrl, sshInfo));
	throw new CommitValidationException(errMsg, messages);
	}
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/**
	* If this is the special project configuration branch, validate the config.
	*/
	public static class ConfigValidator implements CommitValidationListener {
	private final RefControl refControl;
	private final Repository repo;

	public ConfigValidator(RefControl refControl, Repository repo) {
	this.refControl = refControl;
	this.repo = repo;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();

	if (GitRepositoryManager.REF_CONFIG.equals(refControl.getRefName())) {
	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	try {
	ProjectConfig cfg =
	new ProjectConfig(receiveEvent.project.getNameKey());
	cfg.load(repo, receiveEvent.command.getNewId());
	if (!cfg.getValidationErrors().isEmpty()) {
	addError("Invalid project configuration:", messages);
	for (ValidationError err : cfg.getValidationErrors()) {
	addError(" " + err.getMessage(), messages);
	}
	throw new ConfigInvalidException("invalid project configuration");
	}
	} catch (Exception e) {
	log.error("User " + currentUser.getUserName()
	+ " tried to push invalid project configuration "
	+ receiveEvent.command.getNewId().name() + " for "
	+ receiveEvent.project.getName(), e);
	throw new CommitValidationException("invalid project configuration",
	messages);
	}
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/** Require permission to upload merges. */
	public static class UploadMergesPermissionValidator implements
	CommitValidationListener {
	private final RefControl refControl;

	public UploadMergesPermissionValidator(RefControl refControl) {
	this.refControl = refControl;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	if (receiveEvent.commit.getParentCount() > 1
	&& !refControl.canUploadMerges()) {
	throw new CommitValidationException("you are not allowed to upload merges");
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/** Execute commit validation plug-ins */
	public static class PluginCommitValidationListener implements
	CommitValidationListener {
	private final DynamicSet<CommitValidationListener> commitValidationListeners;

	public PluginCommitValidationListener(
	final DynamicSet<CommitValidationListener> commitValidationListeners) {
	this.commitValidationListeners = commitValidationListeners;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	for (CommitValidationListener validator : commitValidationListeners) {
	try {
	messages.addAll(validator.onCommitReceived(receiveEvent));
	} catch (CommitValidationException e) {
	messages.addAll(e.getMessages());
	throw new CommitValidationException(e.getMessage(), messages);
	}
	}
	return messages;
	}
	}

	public static class SignedOffByValidator implements CommitValidationListener {
	private final RefControl refControl;

	public SignedOffByValidator(RefControl refControl, String canonicalWebUrl) {
	this.refControl = refControl;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
	final PersonIdent committer = receiveEvent.commit.getCommitterIdent();
	final PersonIdent author = receiveEvent.commit.getAuthorIdent();
	final ProjectControl projectControl = refControl.getProjectControl();

	if (projectControl.getProjectState().isUseSignedOffBy()) {
	boolean sboAuthor = false, sboCommitter = false, sboMe = false;
	for (final FooterLine footer : receiveEvent.commit.getFooterLines()) {
	if (footer.matches(FooterKey.SIGNED_OFF_BY)) {
	final String e = footer.getEmailAddress();
	if (e != null) {
	sboAuthor \|= author.getEmailAddress().equals(e);
	sboCommitter \|= committer.getEmailAddress().equals(e);
	sboMe \|= currentUser.getEmailAddresses().contains(e);
	}
	}
	}
	if (!sboAuthor && !sboCommitter && !sboMe
	&& !refControl.canForgeCommitter()) {
	throw new CommitValidationException(
	"not Signed-off-by author/committer/uploader in commit message footer");
	}
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/** Require that author matches the uploader. */
	public static class AuthorUploaderValidator implements
	CommitValidationListener {
	private final RefControl refControl;
	private final String canonicalWebUrl;

	public AuthorUploaderValidator(RefControl refControl, String canonicalWebUrl) {
	this.refControl = refControl;
	this.canonicalWebUrl = canonicalWebUrl;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
	final PersonIdent author = receiveEvent.commit.getAuthorIdent();

	if (!currentUser.getEmailAddresses().contains(author.getEmailAddress())
	&& !refControl.canForgeAuthor()) {
	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();

	messages.add(getInvalidEmailError(receiveEvent.commit, "author", author,
	currentUser, canonicalWebUrl));
	throw new CommitValidationException("invalid author", messages);
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/** Require that committer matches the uploader. */
	public static class CommitterUploaderValidator implements
	CommitValidationListener {
	private final RefControl refControl;
	private final String canonicalWebUrl;

	public CommitterUploaderValidator(RefControl refControl,
	String canonicalWebUrl) {
	this.refControl = refControl;
	this.canonicalWebUrl = canonicalWebUrl;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	IdentifiedUser currentUser = (IdentifiedUser) refControl.getCurrentUser();
	final PersonIdent committer = receiveEvent.commit.getCommitterIdent();
	if (!currentUser.getEmailAddresses()
	.contains(committer.getEmailAddress())
	&& !refControl.canForgeCommitter()) {
	List<CommitValidationMessage> messages =
	new LinkedList<CommitValidationMessage>();
	messages.add(getInvalidEmailError(receiveEvent.commit, "committer", committer,
	currentUser, canonicalWebUrl));
	throw new CommitValidationException("invalid committer", messages);
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	/**
	* Don't allow the user to amend a merge created by Gerrit Code Review. This
	* seems to happen all too often, due to users not paying any attention to
	* what they are doing.
	*/
	public static class AmendedGerritMergeCommitValidationListener implements
	CommitValidationListener {
	private final PersonIdent gerritIdent;
	private final RefControl refControl;

	public AmendedGerritMergeCommitValidationListener(
	final RefControl refControl, final PersonIdent gerritIdent) {
	this.refControl = refControl;
	this.gerritIdent = gerritIdent;
	}

	@Override
	public List<CommitValidationMessage> onCommitReceived(
	CommitReceivedEvent receiveEvent) throws CommitValidationException {
	final PersonIdent author = receiveEvent.commit.getAuthorIdent();

	if (receiveEvent.commit.getParentCount() > 1
	&& author.getName().equals(gerritIdent.getName())
	&& author.getEmailAddress().equals(gerritIdent.getEmailAddress())
	&& !refControl.canForgeGerritServerIdentity()) {
	throw new CommitValidationException("do not amend merges not made by you");
	}
	return Collections.<CommitValidationMessage>emptyList();
	}
	}

	private static CommitValidationMessage getInvalidEmailError(RevCommit c, String type,
	PersonIdent who, IdentifiedUser currentUser, String canonicalWebUrl) {
	StringBuilder sb = new StringBuilder();
	sb.append("\n");
	sb.append("ERROR: In commit " + c.name() + "\n");
	sb.append("ERROR: " + type + " email address " + who.getEmailAddress()
	+ "\n");
	sb.append("ERROR: does not match your user account.\n");
	sb.append("ERROR:\n");
	if (currentUser.getEmailAddresses().isEmpty()) {
	sb.append("ERROR: You have not registered any email addresses.\n");
	} else {
	sb.append("ERROR: The following addresses are currently registered:\n");
	for (String address : currentUser.getEmailAddresses()) {
	sb.append("ERROR: " + address + "\n");
	}
	}
	sb.append("ERROR:\n");
	if (canonicalWebUrl != null) {
	sb.append("ERROR: To register an email address, please visit:\n");
	sb.append("ERROR: " + canonicalWebUrl + "#" + PageLinks.SETTINGS_CONTACT
	+ "\n");
	}
	sb.append("\n");
	return new CommitValidationMessage(sb.toString(), false);
	}

	/**
	* We handle 3 cases:
	* 1. No change id in the commit message at all.
	* 2. Change id last in the commit message but missing empty line to create the footer.
	* 3. There is a change-id somewhere in the commit message, but we ignore it.
	*
	* @return The fixed up commit message
	*/
	private static CommitValidationMessage getFixedCommitMsgWithChangeId(final String errMsg,
	final RevCommit c, final IdentifiedUser currentUser,
	String canonicalWebUrl, final SshInfo sshInfo) {
	final String changeId = "Change-Id:";
	StringBuilder sb = new StringBuilder();
	sb.append("ERROR: ").append(errMsg);
	sb.append('\n');
	sb.append("Suggestion for commit message:\n");

	if (c.getFullMessage().indexOf(changeId) == -1) {
	sb.append(c.getFullMessage());
	sb.append('\n');
	sb.append(changeId).append(" I").append(c.name());
	} else {
	String lines[] = c.getFullMessage().trim().split("\n");
	String lastLine = lines.length > 0 ? lines[lines.length - 1] : "";

	if (lastLine.indexOf(changeId) == 0) {
	for (int i = 0; i < lines.length - 1; i++) {
	sb.append(lines[i]);
	sb.append('\n');
	}

	sb.append('\n');
	sb.append(lastLine);
	} else {
	sb.append(c.getFullMessage());
	sb.append('\n');
	sb.append(changeId).append(" I").append(c.name());
	sb.append('\n');
	sb.append("Hint: A potential Change-Id was found, but it was not in the ");
	sb.append("footer (last paragraph) of the commit message.");
	}
	}
	sb.append('\n');
	sb.append('\n');
	sb.append("Hint: To automatically insert Change-Id, install the hook:\n");
	sb.append(getCommitMessageHookInstallationHint(currentUser,
	canonicalWebUrl, sshInfo)).append('\n');
	sb.append('\n');

	return new CommitValidationMessage(sb.toString(), false);
	}

	private static String getCommitMessageHookInstallationHint(
	final IdentifiedUser currentUser, String canonicalWebUrl,
	final SshInfo sshInfo) {
	final List<HostKey> hostKeys = sshInfo.getHostKeys();

	// If there are no SSH keys, the commit-msg hook must be installed via
	// HTTP(S)
	if (hostKeys.isEmpty()) {
	String p = ".git/hooks/commit-msg";
	return String.format(
	" curl -o %s %s/tools/hooks/commit-msg ; chmod +x %s", p,
	getGerritUrl(canonicalWebUrl), p);
	}

	// SSH keys exist, so the hook can be installed with scp.
	String sshHost;
	int sshPort;
	String host = hostKeys.get(0).getHost();
	int c = host.lastIndexOf(':');
	if (0 <= c) {
	if (host.startsWith("*:")) {
	sshHost = getGerritHost(canonicalWebUrl);
	} else {
	sshHost = host.substring(0, c);
	}
	sshPort = Integer.parseInt(host.substring(c + 1));
	} else {
	sshHost = host;
	sshPort = 22;
	}

	return String.format(" scp -p -P %d %s@%s:hooks/commit-msg .git/hooks/",
	sshPort, currentUser.getUserName(), sshHost);
	}

	/**
	* Get the Gerrit URL.
	*
	* @return the canonical URL (with any trailing slash removed) if it is
	* configured, otherwise fall back to "http://hostname" where hostname
	* is the value returned by {@link #getGerritHost()}.
	*/
	private static String getGerritUrl(String canonicalWebUrl) {
	if (canonicalWebUrl != null) {
	if (canonicalWebUrl.endsWith("/")) {
	return canonicalWebUrl.substring(0, canonicalWebUrl.lastIndexOf("/"));
	}
	return canonicalWebUrl;
	} else {
	return "http://" + getGerritHost(canonicalWebUrl);
	}
	}

	/**
	* Get the Gerrit hostname.
	*
	* @return the hostname from the canonical URL if it is configured, otherwise
	* whatever the OS says the hostname is.
	*/
	private static String getGerritHost(String canonicalWebUrl) {
	String host;
	if (canonicalWebUrl != null) {
	try {
	host = new URL(canonicalWebUrl).getHost();
	} catch (MalformedURLException e) {
	host = SystemReader.getInstance().getHostname();
	}
	} else {
	host = SystemReader.getInstance().getHostname();
	}
	return host;
	}

	private static void addError(String error,
	List<CommitValidationMessage> messages) {
	messages.add(new CommitValidationMessage(error, true));
	}
	}