merge with develop

CHANGELOG.md

@@ -5,9 +5,14 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
+
 ### Added
+- Introduced merge detection for receive hooks ([#1278](https://github.com/scm-manager/scm-manager/pull/1278))
 - Anonymous mode for the web ui ([#1284](https://github.com/scm-manager/scm-manager/pull/1284))
 
+### Fixed
+- Repository names may not end with ".git" ([#1277](https://github.com/scm-manager/scm-manager/pull/1277))
+
 ## [2.3.1] - 2020-08-04
 ### Added
 - New api to resolve SCM-Manager root url ([#1276](https://github.com/scm-manager/scm-manager/pull/1276))

docs/en/administration/logging.md

@@ -25,7 +25,7 @@ The location of the file depends also on the type of installation.
 
 | Type of Installation | Path |
 |----------------------|---------|
-| Docker | /opt/scm-server/conf/logging.xml |
+| Docker | /etc/scm/logging.xml |
 | RPM | /etc/scm/logging.xml |
 | DEB | /etc/scm/logging.xml |
 | Unix | $EXTRACT_PATH/scm-server/conf/logging.xml |

docs/en/development/integration-tests.md

@@ -0,0 +1,24 @@
+---
+title: Integration Tests
+subtitle: How to run integration tests
+displayToc: false
+---
+
+You can find the integration tests in the module **scm-it** (and a few still in **scm-webapp**). To run them,
+simply start maven with the profile `it`:
+
+```
+mvn install -Pit -DskipUnitTests -pl :scm-webapp,:scm-it
+```
+
+This will start a jetty server and execute all integration tests in the maven phase `integration-test` using the
+normal failsafe plugin. Integration tests are all classes ending with `ITCase` and are written using JUnit.
+
+To develop integration tests, you should start a local server with the **scm-integration-test-plugin**. This plugin is
+used as a way to introspect server internals. For example you can register event listeners here and access their
+triggers with a REST endpoint. Of course, this plugin is not and should not be installed in productive systems.
+You can start the server with this plugin using the following maven call:
+
+```
+mvn run -pl :scm-integration-test-plugin
+```

docs/en/navigation.yml

@@ -31,6 +31,7 @@
   - /development/definition-of-done/
   - /development/ui-dod/
   - /development/decision-table/
+  - /development/integration-tests/
 
 - section: Plugin Development
   entries:

scm-core/src/main/java/sonia/scm/repository/api/HookContext.java

@@ -33,6 +33,7 @@ import sonia.scm.repository.Changeset;
 import sonia.scm.repository.PreProcessorUtil;
 import sonia.scm.repository.Repository;
 import sonia.scm.repository.spi.HookContextProvider;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
 
 /**
  * The context for all repository hooks. With the {@link HookContext} class it
@@ -43,8 +44,7 @@ import sonia.scm.repository.spi.HookContextProvider;
  * @author Sebastian Sdorra
  * @since 1.33
  */
-public final class HookContext
+public final class HookContext {
-{
 
   /**
    * the logger for HookContext
@@ -52,8 +52,6 @@ public final class HookContext
   private static final Logger logger =
     LoggerFactory.getLogger(HookContext.class);
 
-  //~--- constructors ---------------------------------------------------------
-
   /**
    * Constructs ...
    *
@@ -62,9 +60,7 @@ public final class HookContext
    * @param repository
    * @param preProcessorUtil
    */
-  HookContext(HookContextProvider provider, Repository repository,
+  HookContext(HookContextProvider provider, Repository repository, PreProcessorUtil preProcessorUtil) {
-    PreProcessorUtil preProcessorUtil)
-  {
     this.provider = provider;
     this.repository = repository;
     this.preProcessorUtil = preProcessorUtil;
@@ -83,13 +79,9 @@ public final class HookContext
    *
    * @since 1.45
    */
-  public HookBranchProvider getBranchProvider()
+  public HookBranchProvider getBranchProvider() {
-  {
+    logger.debug("create branch provider for repository {}",
-    if (logger.isDebugEnabled())
+      repository.getName());
-    {
-      logger.debug("create branch provider for repository {}",
-        repository.getName());
-    }
 
     return provider.getBranchProvider();
   }
@@ -105,13 +97,9 @@ public final class HookContext
    *
    * @since 1.50
    */
-  public HookTagProvider getTagProvider()
+  public HookTagProvider getTagProvider() {
-  {
+    logger.debug("create tag provider for repository {}",
-    if (logger.isDebugEnabled())
+      repository.getName());
-    {
-      logger.debug("create tag provider for repository {}",
-        repository.getName());
-    }
 
     return provider.getTagProvider();
   }
@@ -126,21 +114,15 @@ public final class HookContext
    * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
    */
-  public HookChangesetBuilder getChangesetProvider()
+  public HookChangesetBuilder getChangesetProvider() {
-  {
+    logger.debug("create changeset provider for repository {}",
-    if (logger.isDebugEnabled())
+      repository.getName());
-    {
-      logger.debug("create changeset provider for repository {}",
-        repository.getName());
-    }
 
-    //J-
     return new HookChangesetBuilder(
       repository,
       preProcessorUtil,
       provider.getChangesetProvider()
     );
-    //J+
   }
 
   /**
@@ -156,17 +138,29 @@ public final class HookContext
    * @throws HookFeatureIsNotSupportedException if the feature is not supported
    *  by the underlying provider
    */
-  public HookMessageProvider getMessageProvider()
+  public HookMessageProvider getMessageProvider() {
-  {
+    logger.debug("create message provider for repository {}",
-    if (logger.isDebugEnabled())
+      repository.getName());
-    {
-      logger.debug("create message provider for repository {}",
-        repository.getName());
-    }
 
     return provider.getMessageProvider();
   }
 
+  /**
+   * Returns a {@link HookMergeDetectionProvider} which is able to check whether two
+   * branches have been merged with the incoming changesets.
+   *
+   * @return {@link HookMergeDetectionProvider} which is able to detect merges.
+   *
+   * @throws HookFeatureIsNotSupportedException if the feature is not supported
+   *  by the underlying provider
+   */
+  public HookMergeDetectionProvider getMergeDetectionProvider() {
+    logger.debug("create merge detection provider for repository {}",
+      repository.getName());
+
+    return provider.getMergeDetectionProvider();
+  }
+
   /**
    * Returns true if the underlying provider support the requested feature.
    *

scm-core/src/main/java/sonia/scm/repository/api/HookFeature.java

@@ -55,5 +55,12 @@ public enum HookFeature
    *
    * @since 1.50
    */
-  TAG_PROVIDER;
+  TAG_PROVIDER,
+
+  /**
+   * Provider to detect merges
+   *
+   * @since 2.4.0
+   */
+  MERGE_DETECTION_PROVIDER
 }

scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java

@@ -118,6 +118,16 @@ public abstract class HookContextProvider
     throw new HookFeatureIsNotSupportedException(HookFeature.CHANGESET_PROVIDER);
   }
 
+  /**
+   * Return the provider specific {@link HookMergeDetectionProvider} or throws a {@link HookFeatureIsNotSupportedException}.
+   *
+   * @return provider specific {@link HookMergeDetectionProvider}
+   */
+  public HookMergeDetectionProvider getMergeDetectionProvider()
+  {
+    throw new HookFeatureIsNotSupportedException(HookFeature.MERGE_DETECTION_PROVIDER);
+  }
+
   //~--- methods --------------------------------------------------------------
 
   /**

scm-core/src/main/java/sonia/scm/repository/spi/HookMergeDetectionProvider.java

@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.spi;
+
+/**
+ * @since 2.4.0
+ */
+public interface HookMergeDetectionProvider {
+
+  /**
+   * Checks whether <code>branch</code> has been merged into <code>target</code>. So this will also return
+   * <code>true</code>, when <code>branch</code> has been deleted with this change.
+   *
+   * @param target The name of the branch to check, whether the other branch has been merged into.
+   * @param branch The name of the branch to check, whether it has been merged into the other branch.
+   * @return <code>true</code> when <code>branch</code> has been merged into <code>target</code>, <code>false</code>
+   * otherwise.
+   */
+  boolean branchesMerged(String target, String branch);
+}

scm-it/pom.xml

@@ -192,6 +192,7 @@
             <version>2.10</version>
             <configuration>
               <artifactItems>
+                <!-- Copy war file -->
                 <artifactItem>
                   <groupId>sonia.scm</groupId>
                   <artifactId>scm-webapp</artifactId>
@@ -200,6 +201,15 @@
                   <outputDirectory>${project.build.outputDirectory}</outputDirectory>
                   <destFileName>scm-webapp.war</destFileName>
                 </artifactItem>
+                <!-- Copy integration test plugin -->
+                <artifactItem>
+                  <groupId>sonia.scm.plugins</groupId>
+                  <artifactId>scm-integration-test-plugin</artifactId>
+                  <version>${project.version}</version>
+                  <type>smp</type>
+                  <outputDirectory>${scm.home}/plugins</outputDirectory>
+                  <destFileName>scm-integration-test-plugin.smp</destFileName>
+                </artifactItem>
               </artifactItems>
             </configuration>
             <executions>
@@ -273,7 +283,7 @@
 
       <properties>
         <scm.stage>DEVELOPMENT</scm.stage>
-        <scm.home>target/scm-it</scm.home>
+        <scm.home>${project.parent.build.directory}/scm-it</scm.home>
         <scm-it.logbackConfiguration>${project.basedir}/../scm-webapp/src/main/resources/logback.default.xml</scm-it.logbackConfiguration>
       </properties>
 

scm-it/src/test/java/sonia/scm/it/MergeDetectionITCase.java

@@ -0,0 +1,185 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it;
+
+import io.restassured.RestAssured;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import sonia.scm.it.utils.RepositoryUtil;
+import sonia.scm.it.utils.RestUtil;
+import sonia.scm.it.utils.TestData;
+import sonia.scm.repository.Person;
+import sonia.scm.repository.client.api.RepositoryClient;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static java.lang.String.format;
+import static java.util.Collections.singletonList;
+import static sonia.scm.it.utils.TestData.USER_SCM_ADMIN;
+
+class MergeDetectionITCase {
+
+  private static final Person ARTHUR = new Person("arthur", "arthur@hitchhiker.com");
+
+  RepositoryClient client;
+  String masterFile;
+  String developFile;
+
+  @BeforeEach
+  void createRepository(@TempDir Path tempDir) throws IOException {
+    TestData.createDefault();
+
+    client = RepositoryUtil.createRepositoryClient("git", tempDir.toFile());
+
+    masterFile = createFile(tempDir, "hg2g.md");
+    developFile = createFile(tempDir, "how_to_make_tea.md");
+
+    client.getAddCommand().add(masterFile);
+    client.getCommitCommand().commit(ARTHUR, "Add base file");
+    client.getPushCommand().push();
+
+    client.getBranchCommand().branch("develop");
+    client.getCheckoutCommand().checkout("develop");
+    client.getAddCommand().add(developFile);
+    client.getCommitCommand().commit(ARTHUR, "add more important things");
+    client.getPushCommand().push();
+  }
+
+  @AfterEach
+  void disableMergeDetection() {
+    RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .contentType("application/json")
+      .accept("application/json")
+      .body(toJson("{}"))
+      .post(RestUtil.createResourceUrl("integration-test/merge-detection/"))
+      .then()
+      .statusCode(204);
+  }
+
+  @Test
+  void shouldDetectSimpleMergeAsMerged() throws IOException {
+    client.getCheckoutCommand().checkout("master");
+    client.getMergeCommand().noFf().merge("develop");
+
+    initializeMergeDetection("master", "develop");
+
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isTrue();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isTrue();
+  }
+
+  @Test
+  void shouldDetectFastForwardAsMerged() throws IOException {
+    client.getCheckoutCommand().checkout("master");
+    client.getMergeCommand().merge("develop");
+
+    initializeMergeDetection("master", "develop");
+
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isTrue();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isTrue();
+  }
+
+  @Test
+  void shouldDetectMergeWhenBranchHasBeenDeletedAsMerged() throws IOException {
+    client.getCheckoutCommand().checkout("master");
+    client.getMergeCommand().merge("develop");
+    client.getPushCommand().push();
+
+    initializeMergeDetection("master", "develop");
+
+    client.getDeleteRemoteBranchCommand().delete("develop");
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isTrue();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isTrue();
+  }
+
+  @Test
+  void shouldDetectNormalPushAsNotMerged(@TempDir Path tempDir) throws IOException {
+    client.getCheckoutCommand().checkout("develop");
+    writeFile(tempDir, developFile, "other content");
+    client.getAddCommand().add(developFile);
+    client.getCommitCommand().commit(ARTHUR, "simple commit");
+
+    initializeMergeDetection("master", "develop");
+
+    client.getPushCommand().push();
+
+    Assertions.assertThat(getMergeDetectionResult("preMergeDetection", 0)).isFalse();
+    Assertions.assertThat(getMergeDetectionResult("postMergeDetection", 0)).isFalse();
+  }
+
+  private boolean getMergeDetectionResult(String type, int n) {
+    return RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .accept("application/json")
+      .get(RestUtil.createResourceUrl("integration-test/"))
+      .then()
+      .statusCode(200)
+      .extract()
+      .jsonPath()
+      .getBoolean("_embedded." +
+        type +
+        "[" + n + "].merged");
+  }
+
+  private void initializeMergeDetection(String target, String branch) {
+    RestAssured.given()
+      .auth().preemptive().basic(USER_SCM_ADMIN, USER_SCM_ADMIN)
+      .when()
+      .contentType("application/json")
+      .accept("application/json")
+      .body(toJson(format("{'target': '%s', 'branch': '%s'}", target, branch)))
+      .post(RestUtil.createResourceUrl("integration-test/merge-detection/"))
+      .then()
+      .statusCode(204);
+  }
+
+  private String createFile(Path tempDir, String name) throws IOException {
+    Files.createFile(tempDir.resolve(name));
+    writeFile(tempDir, name, "Some content");
+    return name;
+  }
+
+  private void writeFile(Path tempDir, String name, String content) throws IOException {
+    Path file = tempDir.resolve(name);
+    Files.write(file, singletonList(content));
+  }
+
+  private String toJson(String json) {
+    return json.replaceAll("'", "\"");
+  }
+}

scm-plugins/pom.xml

@@ -45,6 +45,7 @@
     <module>scm-git-plugin</module>
     <module>scm-svn-plugin</module>
     <module>scm-legacy-plugin</module>
+    <module>scm-integration-test-plugin</module>
   </modules>
 
   <dependencies>

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitUtil.java

@@ -337,6 +337,16 @@ public final class GitUtil
     return Strings.nullToEmpty(refName).startsWith(PREFIX_HEADS);
   }
 
+  public static Ref getBranchIdOrCurrentHead(org.eclipse.jgit.lib.Repository gitRepository, String requestedBranch) throws IOException {
+    if ( Strings.isNullOrEmpty(requestedBranch) ) {
+      logger.trace("no default branch configured, use repository head as default");
+      Optional<Ref> repositoryHeadRef = GitUtil.getRepositoryHeadRef(gitRepository);
+      return repositoryHeadRef.orElse(null);
+    } else {
+      return GitUtil.getBranchId(gitRepository, requestedBranch);
+    }
+  }
+
   /**
    * Method description
    *

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/api/GitReceiveHookMergeDetectionProvider.java

@@ -0,0 +1,81 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.api;
+
+import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.ReceiveCommand;
+import sonia.scm.repository.GitUtil;
+import sonia.scm.repository.spi.GitLogComputer;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
+import sonia.scm.repository.spi.LogCommandRequest;
+
+import java.util.List;
+
+public class GitReceiveHookMergeDetectionProvider implements HookMergeDetectionProvider {
+  private final Repository repository;
+  private final String repositoryId;
+  private final List<ReceiveCommand> receiveCommands;
+
+  public GitReceiveHookMergeDetectionProvider(Repository repository, String repositoryId, List<ReceiveCommand> receiveCommands) {
+    this.repository = repository;
+    this.repositoryId = repositoryId;
+    this.receiveCommands = receiveCommands;
+  }
+
+  @Override
+  public boolean branchesMerged(String target, String branch) {
+    LogCommandRequest request = new LogCommandRequest();
+    request.setBranch(findRelevantRevisionForBranchIfToBeUpdated(branch));
+    request.setAncestorChangeset(findRelevantRevisionForBranchIfToBeUpdated(target));
+    request.setPagingLimit(1);
+
+    return new GitLogComputer(repositoryId, repository).compute(request).getTotal() == 0;
+  }
+
+  private String findRelevantRevisionForBranchIfToBeUpdated(String branch) {
+    return receiveCommands
+      .stream()
+      .filter(receiveCommand -> isReceiveCommandForBranch(branch, receiveCommand))
+      .map(this::getRelevantRevision)
+      .map(AnyObjectId::getName)
+      .findFirst()
+      .orElse(branch);
+  }
+
+  private boolean isReceiveCommandForBranch(String branch, ReceiveCommand receiveCommand) {
+    return receiveCommand.getType() != ReceiveCommand.Type.CREATE
+      && GitUtil.getBranch(receiveCommand.getRef()).equals(branch);
+  }
+
+  private ObjectId getRelevantRevision(ReceiveCommand receiveCommand) {
+    if (receiveCommand.getType() == ReceiveCommand.Type.DELETE) {
+      return receiveCommand.getOldId();
+    } else {
+      return receiveCommand.getNewId();
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/AbstractGitCommand.java

@@ -41,7 +41,6 @@ import org.eclipse.jgit.transport.PushResult;
 import org.eclipse.jgit.transport.RemoteRefUpdate;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import sonia.scm.repository.GitUtil;
 import sonia.scm.repository.GitWorkingCopyFactory;
 import sonia.scm.repository.InternalRepositoryException;
 import sonia.scm.repository.Person;
@@ -59,6 +58,7 @@ import static java.util.Optional.empty;
 import static java.util.Optional.of;
 import static sonia.scm.ContextEntry.ContextBuilder.entity;
 import static sonia.scm.NotFoundException.notFound;
+import static sonia.scm.repository.GitUtil.getBranchIdOrCurrentHead;
 
 //~--- JDK imports ------------------------------------------------------------
 
@@ -123,15 +123,9 @@ class AbstractGitCommand
   Ref getBranchOrDefault(Repository gitRepository, String requestedBranch) throws IOException {
     if ( Strings.isNullOrEmpty(requestedBranch) ) {
       String defaultBranchName = context.getConfig().getDefaultBranch();
-      if (!Strings.isNullOrEmpty(defaultBranchName)) {
+      return getBranchIdOrCurrentHead(gitRepository, defaultBranchName);
-        return GitUtil.getBranchId(gitRepository, defaultBranchName);
-      } else {
-        logger.trace("no default branch configured, use repository head as default");
-        Optional<Ref> repositoryHeadRef = GitUtil.getRepositoryHeadRef(gitRepository);
-        return repositoryHeadRef.orElse(null);
-      }
     } else {
-      return GitUtil.getBranchId(gitRepository, requestedBranch);
+      return getBranchIdOrCurrentHead(gitRepository, requestedBranch);
     }
   }
 

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitHookContextProvider.java

@@ -26,22 +26,21 @@ package sonia.scm.repository.spi;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.transport.ReceiveCommand;
 import org.eclipse.jgit.transport.ReceivePack;
-
 import sonia.scm.repository.api.GitHookBranchProvider;
 import sonia.scm.repository.api.GitHookMessageProvider;
+import sonia.scm.repository.api.GitHookTagProvider;
+import sonia.scm.repository.api.GitReceiveHookMergeDetectionProvider;
 import sonia.scm.repository.api.HookBranchProvider;
 import sonia.scm.repository.api.HookFeature;
 import sonia.scm.repository.api.HookMessageProvider;
-
+import sonia.scm.repository.api.HookTagProvider;
-//~--- JDK imports ------------------------------------------------------------
 
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Set;
-import sonia.scm.repository.api.GitHookTagProvider;
-import sonia.scm.repository.api.HookTagProvider;
 
 /**
  *
@@ -50,24 +49,34 @@ import sonia.scm.repository.api.HookTagProvider;
 public class GitHookContextProvider extends HookContextProvider
 {
 
-  /** Field description */
+  /**
-  private static final Set<HookFeature> SUPPORTED_FEATURES =
+   * Field description
-    EnumSet.of(HookFeature.MESSAGE_PROVIDER, HookFeature.CHANGESET_PROVIDER,
+   */
-      HookFeature.BRANCH_PROVIDER, HookFeature.TAG_PROVIDER);
+  private static final Set<HookFeature> SUPPORTED_FEATURES = EnumSet.of(
+    HookFeature.MESSAGE_PROVIDER,
+    HookFeature.CHANGESET_PROVIDER,
+    HookFeature.BRANCH_PROVIDER,
+    HookFeature.TAG_PROVIDER,
+    HookFeature.MERGE_DETECTION_PROVIDER
+  );
 
   //~--- constructors ---------------------------------------------------------
 
   /**
    * Constructs a new instance
-   *
    * @param receivePack git receive pack
    * @param receiveCommands received commands
    */
-  public GitHookContextProvider(ReceivePack receivePack,
+  public GitHookContextProvider(
-    List<ReceiveCommand> receiveCommands)
+    ReceivePack receivePack,
-  {
+    List<ReceiveCommand> receiveCommands,
+    Repository repository,
+    String repositoryId
+  ) {
     this.receivePack = receivePack;
     this.receiveCommands = receiveCommands;
+    this.repository = repository;
+    this.repositoryId = repositoryId;
     this.changesetProvider = new GitHookChangesetProvider(receivePack,
       receiveCommands);
   }
@@ -99,20 +108,20 @@ public class GitHookContextProvider extends HookContextProvider
     return changesetProvider;
   }
 
+  @Override
+  public HookMergeDetectionProvider getMergeDetectionProvider() {
+    return new GitReceiveHookMergeDetectionProvider(repository, repositoryId, receiveCommands);
+  }
+
   @Override
   public Set<HookFeature> getSupportedFeatures()
   {
     return SUPPORTED_FEATURES;
   }
 
-  //~--- fields ---------------------------------------------------------------
-
-  /** Field description */
   private final GitHookChangesetProvider changesetProvider;
-
-  /** Field description */
   private final List<ReceiveCommand> receiveCommands;
-
-  /** Field description */
   private final ReceivePack receivePack;
+  private final Repository repository;
+  private final String repositoryId;
 }

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitLogCommand.java

@@ -27,19 +27,12 @@ package sonia.scm.repository.spi;
 //~--- non-JDK imports --------------------------------------------------------
 
 import com.google.common.base.Strings;
-import com.google.common.collect.Lists;
-import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
-import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
-import org.eclipse.jgit.treewalk.filter.PathFilter;
-import org.eclipse.jgit.treewalk.filter.TreeFilter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import sonia.scm.NotFoundException;
 import sonia.scm.repository.Changeset;
 import sonia.scm.repository.ChangesetPagingResult;
 import sonia.scm.repository.GitChangesetConverter;
@@ -48,9 +41,6 @@ import sonia.scm.repository.InternalRepositoryException;
 import sonia.scm.util.IOUtil;
 
 import java.io.IOException;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
 
 import static sonia.scm.ContextEntry.ContextBuilder.entity;
 import static sonia.scm.NotFoundException.notFound;
@@ -183,123 +173,14 @@ public class GitLogCommand extends AbstractGitCommand implements LogCommand
   @Override
   @SuppressWarnings("unchecked")
   public ChangesetPagingResult getChangesets(LogCommandRequest request) {
-    if (logger.isDebugEnabled()) {
+    try (org.eclipse.jgit.lib.Repository gitRepository = open()) {
-      logger.debug("fetch changesets for request: {}", request);
+      if (Strings.isNullOrEmpty(request.getBranch())) {
-    }
+        request.setBranch(context.getConfig().getDefaultBranch());
-
-    ChangesetPagingResult changesets = null;
-    GitChangesetConverter converter = null;
-    RevWalk revWalk = null;
-
-    try (org.eclipse.jgit.lib.Repository repository = open()) {
-      if (!repository.getAllRefs().isEmpty()) {
-        int counter = 0;
-        int start = request.getPagingStart();
-
-        if (start < 0) {
-          if (logger.isErrorEnabled()) {
-            logger.error("start parameter is negative, reset to 0");
-          }
-
-          start = 0;
-        }
-
-        List<Changeset> changesetList = Lists.newArrayList();
-        int limit = request.getPagingLimit();
-        ObjectId startId = null;
-
-        if (!Strings.isNullOrEmpty(request.getStartChangeset())) {
-          startId = repository.resolve(request.getStartChangeset());
-        }
-
-        ObjectId endId = null;
-
-        if (!Strings.isNullOrEmpty(request.getEndChangeset())) {
-          endId = repository.resolve(request.getEndChangeset());
-        }
-
-        Ref branch = getBranchOrDefault(repository,request.getBranch());
-
-        ObjectId ancestorId = null;
-
-        if (!Strings.isNullOrEmpty(request.getAncestorChangeset())) {
-          ancestorId = repository.resolve(request.getAncestorChangeset());
-          if (ancestorId == null) {
-            throw notFound(entity(REVISION, request.getAncestorChangeset()).in(this.repository));
-          }
-        }
-
-        revWalk = new RevWalk(repository);
-
-        converter = new GitChangesetConverter(repository, revWalk);
-
-        if (!Strings.isNullOrEmpty(request.getPath())) {
-          revWalk.setTreeFilter(
-            AndTreeFilter.create(
-              PathFilter.create(request.getPath()), TreeFilter.ANY_DIFF));
-        }
-
-        if (branch != null) {
-          if (startId != null) {
-            revWalk.markStart(revWalk.lookupCommit(startId));
-          } else {
-            revWalk.markStart(revWalk.lookupCommit(branch.getObjectId()));
-          }
-
-          if (ancestorId != null) {
-            revWalk.markUninteresting(revWalk.lookupCommit(ancestorId));
-          }
-
-          Iterator<RevCommit> iterator = revWalk.iterator();
-
-          while (iterator.hasNext()) {
-            RevCommit commit = iterator.next();
-
-            if ((counter >= start)
-              && ((limit < 0) || (counter < start + limit))) {
-              changesetList.add(converter.createChangeset(commit));
-            }
-
-            counter++;
-
-            if (commit.getId().equals(endId)) {
-              break;
-            }
-          }
-        } else if (ancestorId != null) {
-          throw notFound(entity(REVISION, request.getBranch()).in(this.repository));
-        }
-
-        if (branch != null) {
-          changesets = new ChangesetPagingResult(counter, changesetList, GitUtil.getBranch(branch.getName()));
-        } else {
-          changesets = new ChangesetPagingResult(counter, changesetList);
-        }
-      } else if (logger.isWarnEnabled()) {
-        logger.warn("the repository {} seems to be empty",
-          this.repository.getName());
-
-        changesets = new ChangesetPagingResult(0, Collections.EMPTY_LIST);
       }
+      return new GitLogComputer(this.repository.getId(), gitRepository).compute(request);
+    } catch (IOException e) {
+      throw new InternalRepositoryException(repository, "could not create change log", e);
     }
-    catch (MissingObjectException e)
-    {
-      throw notFound(entity(REVISION, e.getObjectId().getName()).in(repository));
-    }
-    catch (NotFoundException e)
-    {
-      throw e;
-    }
-    catch (Exception ex)
-    {
-      throw new InternalRepositoryException(repository, "could not create change log", ex);
-    }
-    finally
-    {
-      IOUtil.close(converter);
-      GitUtil.release(revWalk);
-    }
-
-    return changesets;
   }
+
 }

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/spi/GitLogComputer.java

@@ -0,0 +1,186 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.spi;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.Lists;
+import org.eclipse.jgit.errors.InvalidObjectIdException;
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
+import org.eclipse.jgit.treewalk.filter.PathFilter;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.NotFoundException;
+import sonia.scm.repository.Changeset;
+import sonia.scm.repository.ChangesetPagingResult;
+import sonia.scm.repository.GitChangesetConverter;
+import sonia.scm.repository.GitUtil;
+import sonia.scm.repository.InternalRepositoryException;
+import sonia.scm.util.IOUtil;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+import static sonia.scm.NotFoundException.notFound;
+
+public class GitLogComputer {
+
+  private static final Logger LOG = LoggerFactory.getLogger(GitLogComputer.class);
+
+  private final String repositoryId;
+  private final Repository gitRepository;
+
+  public GitLogComputer(String repositoryId, Repository repository) {
+    this.repositoryId = repositoryId;
+    this.gitRepository = repository;
+  }
+
+  public ChangesetPagingResult compute(LogCommandRequest request) {
+    LOG.debug("fetch changesets for request: {}", request);
+
+    GitChangesetConverter converter = null;
+    RevWalk revWalk = null;
+
+    try {
+      if (!gitRepository.getAllRefs().isEmpty()) {
+        int counter = 0;
+        int start = request.getPagingStart();
+
+        if (start < 0) {
+          LOG.error("start parameter is negative, reset to 0");
+
+          start = 0;
+        }
+
+        List<Changeset> changesetList = Lists.newArrayList();
+        int limit = request.getPagingLimit();
+        ObjectId startId = null;
+
+        if (!Strings.isNullOrEmpty(request.getStartChangeset())) {
+          startId = gitRepository.resolve(request.getStartChangeset());
+        }
+
+        ObjectId endId = null;
+
+        if (!Strings.isNullOrEmpty(request.getEndChangeset())) {
+          endId = gitRepository.resolve(request.getEndChangeset());
+        }
+
+        Ref branch = GitUtil.getBranchIdOrCurrentHead(gitRepository, request.getBranch());
+        ObjectId branchId;
+        if (branch == null) {
+          if (request.getBranch() != null) {
+            try {
+              branchId = ObjectId.fromString(request.getBranch());
+            } catch (InvalidObjectIdException e) {
+              throw notFound(entity(GitLogCommand.REVISION, request.getBranch()).in(sonia.scm.repository.Repository.class, repositoryId));
+            }
+          } else {
+            branchId = null;
+          }
+        } else {
+          branchId = branch.getObjectId();
+        }
+
+        ObjectId ancestorId = null;
+
+        if (!Strings.isNullOrEmpty(request.getAncestorChangeset())) {
+          ancestorId = gitRepository.resolve(request.getAncestorChangeset());
+          if (ancestorId == null) {
+            throw notFound(entity(GitLogCommand.REVISION, request.getAncestorChangeset()).in(sonia.scm.repository.Repository.class, repositoryId));
+          }
+        }
+
+        revWalk = new RevWalk(gitRepository);
+
+        converter = new GitChangesetConverter(gitRepository, revWalk);
+
+        if (!Strings.isNullOrEmpty(request.getPath())) {
+          revWalk.setTreeFilter(
+            AndTreeFilter.create(
+              PathFilter.create(request.getPath()), TreeFilter.ANY_DIFF));
+        }
+
+        if (branchId != null) {
+          if (startId != null) {
+            revWalk.markStart(revWalk.lookupCommit(startId));
+          } else {
+            revWalk.markStart(revWalk.lookupCommit(branchId));
+          }
+
+          if (ancestorId != null) {
+            revWalk.markUninteresting(revWalk.lookupCommit(ancestorId));
+          }
+
+          Iterator<RevCommit> iterator = revWalk.iterator();
+
+          while (iterator.hasNext()) {
+            RevCommit commit = iterator.next();
+
+            if ((counter >= start)
+              && ((limit < 0) || (counter < start + limit))) {
+              changesetList.add(converter.createChangeset(commit));
+            }
+
+            counter++;
+
+            if (commit.getId().equals(endId)) {
+              break;
+            }
+          }
+        } else if (ancestorId != null) {
+          throw notFound(entity(GitLogCommand.REVISION, request.getBranch()).in(sonia.scm.repository.Repository.class, repositoryId));
+        }
+
+        if (branch != null) {
+          return new ChangesetPagingResult(counter, changesetList, GitUtil.getBranch(branch.getName()));
+        } else {
+          return new ChangesetPagingResult(counter, changesetList);
+        }
+      } else {
+        LOG.debug("the repository with id {} seems to be empty", this.repositoryId);
+
+        return new ChangesetPagingResult(0, Collections.emptyList());
+      }
+    } catch (MissingObjectException e) {
+      throw notFound(entity(GitLogCommand.REVISION, e.getObjectId().getName()).in(sonia.scm.repository.Repository.class, repositoryId));
+    } catch (NotFoundException e) {
+      throw e;
+    } catch (Exception ex) {
+      throw new InternalRepositoryException(entity(sonia.scm.repository.Repository.class, repositoryId).build(), "could not create change log", ex);
+    } finally {
+      IOUtil.close(converter);
+      GitUtil.release(revWalk);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/web/GitReceiveHook.java

@@ -122,8 +122,7 @@ public class GitReceiveHook implements PreReceiveHook, PostReceiveHook
 
       logger.trace("resolved repository to {}", repositoryId);
 
-      GitHookContextProvider context = new GitHookContextProvider(rpack,
+      GitHookContextProvider context = new GitHookContextProvider(rpack, receiveCommands, repository, repositoryId);
-                                         receiveCommands);
 
       hookEventFacade.handle(repositoryId).fireHookEvent(type, context);
 

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitCheckoutCommand.java

@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitCheckoutCommand implements CheckoutCommand {
+
+  private Git git;
+
+  GitCheckoutCommand(Git git) {
+    this.git = git;
+  }
+
+  @Override
+  public void checkout(String name) throws IOException {
+    try {
+      git.checkout().setName(name).call();
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not checkout branch or revision", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitDeleteRemoteBranchCommand.java

@@ -0,0 +1,62 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.PushCommand;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.transport.CredentialsProvider;
+import org.eclipse.jgit.transport.RefSpec;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitDeleteRemoteBranchCommand implements DeleteRemoteBranchCommand {
+
+  private final Git git;
+  private final CredentialsProvider credentialsProvider;
+
+  GitDeleteRemoteBranchCommand(Git git, CredentialsProvider credentialsProvider) {
+    this.git = git;
+    this.credentialsProvider = credentialsProvider;
+  }
+
+  @Override
+  public void delete(String name) throws IOException {
+    try {
+      git.branchDelete().setBranchNames("refs/heads/" + name).call();
+      RefSpec refSpec = new RefSpec()
+        .setSource(null)
+        .setDestination("refs/heads/" + name);
+      PushCommand push = git.push();
+      if (credentialsProvider != null) {
+        push.setCredentialsProvider(credentialsProvider);
+      }
+      push.setRefSpecs(refSpec).call();
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not delete branch", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitMergeCommand.java

@@ -0,0 +1,80 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.api.MergeResult;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+import sonia.scm.repository.Changeset;
+import sonia.scm.repository.GitChangesetConverter;
+import sonia.scm.repository.client.api.RepositoryClientException;
+
+import java.io.IOException;
+
+public class GitMergeCommand implements MergeCommand {
+
+  private final Git git;
+
+  GitMergeCommand(Git git) {
+    this.git = git;
+  }
+
+  @Override
+  public Changeset merge(MergeRequest request) throws IOException {
+    try (GitChangesetConverter converter = new GitChangesetConverter(git.getRepository())) {
+      ObjectId resolved = git.getRepository().resolve(request.getBranch());
+      org.eclipse.jgit.api.MergeCommand mergeCommand = git.merge()
+        .include(request.getBranch(), resolved)
+        .setMessage(request.getMessage());
+
+      switch (request.getFfMode()) {
+        case FF:
+          mergeCommand.setFastForward(org.eclipse.jgit.api.MergeCommand.FastForwardMode.FF);
+          break;
+        case NO_FF:
+          mergeCommand.setFastForward(org.eclipse.jgit.api.MergeCommand.FastForwardMode.NO_FF);
+          break;
+        case FF_ONLY:
+          mergeCommand.setFastForward(org.eclipse.jgit.api.MergeCommand.FastForwardMode.FF_ONLY);
+          break;
+        default:
+          throw new IllegalStateException("Unknown FF mode: " + request.getFfMode());
+      }
+
+      MergeResult mergeResult = mergeCommand
+        .call();
+
+      try (RevWalk revWalk = new RevWalk(git.getRepository())) {
+        RevCommit commit = revWalk.parseCommit(mergeResult.getNewHead());
+        return converter.createChangeset(commit);
+      }
+    } catch (GitAPIException ex) {
+      throw new RepositoryClientException("could not commit changes to repository", ex);
+    }
+  }
+}

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/client/spi/GitRepositoryClientProvider.java

@@ -49,7 +49,7 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
   private static final Set<ClientCommand> SUPPORTED_COMMANDS =
     ImmutableSet.of(ClientCommand.ADD, ClientCommand.REMOVE,
       ClientCommand.COMMIT, ClientCommand.TAG, ClientCommand.BRANCH,
-      ClientCommand.PUSH);
+      ClientCommand.DELETE_REMOTE_BRANCH, ClientCommand.MERGE, ClientCommand.PUSH);
 
   //~--- constructors ---------------------------------------------------------
 
@@ -118,6 +118,16 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
     return new GitBranchCommand(git);
   }
 
+  @Override
+  public DeleteRemoteBranchCommand getDeleteRemoteBranchCommand() {
+    return new GitDeleteRemoteBranchCommand(git, credentialsProvider);
+  }
+
+  @Override
+  public CheckoutCommand getCheckoutCommand() {
+    return new GitCheckoutCommand(git);
+  }
+
   /**
    * Method description
    *
@@ -178,6 +188,11 @@ public class GitRepositoryClientProvider extends RepositoryClientProvider
     return new GitTagCommand(git);
   }
 
+  @Override
+  public MergeCommand getMergeCommand() {
+    return new GitMergeCommand(git);
+  }
+
   @Override
   public File getWorkingCopy() {
     return git.getRepository().getWorkTree();

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/spi/GitDiffCommand_DequoteOutputStreamTest.java

@@ -48,7 +48,7 @@ public class GitDiffCommand_DequoteOutputStreamTest {
     stream.write(bytes, 0, bytes.length);
     stream.flush();
 
-    Assertions.assertThat(buffer.toString()).isEqualTo("diff --git a/file úüþëéåëåé a b/file úüþëéåëåé b\n" +
+    Assertions.assertThat(buffer.toString("UTF-8")).isEqualTo("diff --git a/file úüþëéåëåé a b/file úüþëéåëåé b\n" +
       "new file mode 100644\n" +
       "index 0000000..8cb0607\n" +
       "--- /dev/null\n" +

scm-plugins/scm-integration-test-plugin/pom.xml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    MIT License
+
+    Copyright (c) 2020-present Cloudogu GmbH and Contributors
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>sonia.scm.plugins</groupId>
+    <artifactId>scm-plugins</artifactId>
+    <version>2.4.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>scm-integration-test-plugin</artifactId>
+  <description>Add functions for integration tests. This is not intended for production systems.</description>
+  <version>2.4.0-SNAPSHOT</version>
+  <packaging>smp</packaging>
+
+  <dependencies>
+
+    <dependency>
+      <groupId>javax.servlet</groupId>
+      <artifactId>javax.servlet-api</artifactId>
+      <version>${servlet.version}</version>
+      <scope>provided</scope>
+    </dependency>
+
+  </dependencies>
+</project>

scm-plugins/scm-integration-test-plugin/src/main/java/sonia/scm/it/resource/IntegrationTestResource.java

@@ -0,0 +1,106 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it.resource;
+
+import de.otto.edison.hal.Embedded;
+import de.otto.edison.hal.HalRepresentation;
+import de.otto.edison.hal.Links;
+import lombok.Getter;
+import lombok.Setter;
+import sonia.scm.api.v2.resources.LinkBuilder;
+import sonia.scm.api.v2.resources.ScmPathInfoStore;
+
+import javax.inject.Inject;
+import javax.ws.rs.Consumes;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+
+import static de.otto.edison.hal.Embedded.embeddedBuilder;
+import static de.otto.edison.hal.Links.linkingTo;
+
+/**
+ * Web Service Resource to support integration tests.
+ */
+@Path(IntegrationTestResource.INTEGRATION_TEST_PATH_V2)
+public class IntegrationTestResource {
+
+  static final String INTEGRATION_TEST_PATH_V2 = "v2/integration-test";
+
+  private final ScmPathInfoStore scmPathInfoStore;
+  private final MergeDetectionHelper mergeDetectionHelper;
+
+  @Inject
+  public IntegrationTestResource(ScmPathInfoStore scmPathInfoStore, MergeDetectionHelper mergeDetectionHelper) {
+    this.scmPathInfoStore = scmPathInfoStore;
+    this.mergeDetectionHelper = mergeDetectionHelper;
+  }
+
+  @GET
+  @Path("")
+  @Produces("application/json")
+  public CollectionDto get() {
+    Links links = linkingTo()
+      .self(self())
+      .build();
+    Embedded embedded = embeddedBuilder()
+      .with("preMergeDetection", mergeDetectionHelper.getPreMergeDetections())
+      .with("postMergeDetection", mergeDetectionHelper.getPostMergeDetections())
+      .build();
+    return new CollectionDto(links, embedded);
+  }
+
+  @POST
+  @Path("merge-detection")
+  @Consumes("application/json")
+  public void initMergeDetection(MergeDetectionConfigurationDto mergeDetectionConfiguration) {
+    mergeDetectionHelper.initialize(mergeDetectionConfiguration.getTarget(), mergeDetectionConfiguration.getBranch());
+  }
+
+  private String self() {
+    LinkBuilder linkBuilder = new LinkBuilder(scmPathInfoStore.get(), IntegrationTestResource.class);
+    return linkBuilder.method("get").parameters().href();
+  }
+
+  static class CollectionDto extends HalRepresentation {
+
+    CollectionDto(Links links, Embedded embedded) {
+      super(links, embedded);
+    }
+
+    @Override
+    protected HalRepresentation withEmbedded(String rel, HalRepresentation embeddedItem) {
+      return super.withEmbedded(rel, embeddedItem);
+    }
+  }
+
+  @Getter
+  @Setter
+  static class MergeDetectionConfigurationDto {
+    private String target;
+    private String branch;
+  }
+}

scm-plugins/scm-integration-test-plugin/src/main/java/sonia/scm/it/resource/MergeDetectionHelper.java

@@ -0,0 +1,101 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.it.resource;
+
+import com.github.legman.Subscribe;
+import de.otto.edison.hal.HalRepresentation;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import sonia.scm.EagerSingleton;
+import sonia.scm.plugin.Extension;
+import sonia.scm.repository.PostReceiveRepositoryHookEvent;
+import sonia.scm.repository.PreReceiveRepositoryHookEvent;
+import sonia.scm.repository.RepositoryHookEvent;
+import sonia.scm.repository.spi.HookMergeDetectionProvider;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@EagerSingleton
+@Extension
+public class MergeDetectionHelper {
+
+  private final List<ResultDto> preMergeDetections = new ArrayList<>();
+  private final List<ResultDto> postMergeDetections = new ArrayList<>();
+
+  private String target;
+  private String branch;
+
+  @Subscribe
+  public void handlePreReceiveEvent(PreReceiveRepositoryHookEvent event) {
+    if (target == null || branch == null) {
+      return;
+    }
+    preMergeDetections.add(createDto(event));
+  }
+
+  @Subscribe
+  public void handlePostReceiveEvent(PostReceiveRepositoryHookEvent event) {
+    if (target == null || branch == null) {
+      return;
+    }
+    postMergeDetections.add(createDto(event));
+  }
+
+  public ResultDto createDto(RepositoryHookEvent event) {
+    HookMergeDetectionProvider mergeDetectionProvider = event.getContext().getMergeDetectionProvider();
+    boolean merged = mergeDetectionProvider.branchesMerged(target, branch);
+    return new ResultDto(
+      event.getClass().getSimpleName(),
+      event.getRepository().getNamespace(),
+      event.getRepository().getName(),
+      merged
+    );
+  }
+
+  void initialize(String target, String branch) {
+    this.target = target;
+    this.branch = branch;
+    preMergeDetections.clear();
+    postMergeDetections.clear();
+  }
+
+  public List<ResultDto> getPreMergeDetections() {
+    return preMergeDetections;
+  }
+
+  public List<ResultDto> getPostMergeDetections() {
+    return postMergeDetections;
+  }
+
+  @Getter
+  @AllArgsConstructor
+  static class ResultDto extends HalRepresentation {
+    private String type;
+    private String namespace;
+    private String name;
+    private boolean merged;
+  }
+}

scm-plugins/scm-integration-test-plugin/src/main/resources/META-INF/scm/plugin.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!--
+
+    MIT License
+
+    Copyright (c) 2020-present Cloudogu GmbH and Contributors
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+
+-->
+<!DOCTYPE plugin SYSTEM "https://download.scm-manager.org/dtd/plugin/2.0.0-01.dtd">
+<plugin>
+
+  <scm-version>2</scm-version>
+
+  <information>
+    <displayName>Integration Test Support</displayName>
+    <author>Cloudogu GmbH</author>
+    <category>Test</category>
+  </information>
+
+  <conditions>
+    <min-version>${project.parent.version}</min-version>
+  </conditions>
+
+</plugin>

scm-test/src/main/java/sonia/scm/repository/client/api/CheckoutCommandBuilder.java

@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.repository.client.spi.CheckoutCommand;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class CheckoutCommandBuilder {
+
+  private static final Logger LOG = LoggerFactory.getLogger(CheckoutCommandBuilder.class);
+
+  private final CheckoutCommand command;
+
+  public CheckoutCommandBuilder(CheckoutCommand command) {
+    this.command = command;
+  }
+
+  public CheckoutCommandBuilder checkout(String name) throws IOException {
+    LOG.debug("checkout {}", name);
+
+    command.checkout(name);
+
+    return this;
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/ClientCommand.java

@@ -31,5 +31,5 @@ package sonia.scm.repository.client.api;
  */
 public enum ClientCommand
 {
-  ADD, REMOVE, COMMIT, PUSH, TAG, BRANCH
+  ADD, REMOVE, COMMIT, PUSH, TAG, BRANCH, DELETE_REMOTE_BRANCH, CHECKOUT, MERGE
 }

scm-test/src/main/java/sonia/scm/repository/client/api/DeleteRemoteBranchCommandBuilder.java

@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.repository.client.spi.DeleteRemoteBranchCommand;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class DeleteRemoteBranchCommandBuilder {
+
+  private static final Logger LOG = LoggerFactory.getLogger(DeleteRemoteBranchCommandBuilder.class);
+
+  private DeleteRemoteBranchCommand command;
+
+  public DeleteRemoteBranchCommandBuilder(DeleteRemoteBranchCommand command) {
+    this.command = command;
+  }
+
+  public DeleteRemoteBranchCommandBuilder delete(String name) throws IOException {
+    LOG.debug("delete branch {}", name);
+
+    command.delete(name);
+
+    return this;
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/MergeCommandBuilder.java

@@ -0,0 +1,63 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.api;
+
+import sonia.scm.repository.client.spi.MergeCommand;
+import sonia.scm.repository.client.spi.MergeRequest;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public final class MergeCommandBuilder {
+
+  private final MergeCommand command;
+  private final MergeRequest request = new MergeRequest();
+
+  MergeCommandBuilder(MergeCommand command) {
+    this.command = command;
+  }
+
+  public MergeCommandBuilder ffOnly() {
+    request.setFfMode(MergeRequest.FastForwardMode.FF_ONLY);
+    return this;
+  }
+
+  public MergeCommandBuilder noFf() {
+    request.setFfMode(MergeRequest.FastForwardMode.NO_FF);
+    return this;
+  }
+
+  public MergeCommandBuilder ffIfPossible() {
+    request.setFfMode(MergeRequest.FastForwardMode.FF);
+    return this;
+  }
+
+  public void merge(String branch) throws IOException {
+    request.setBranch(branch);
+    command.merge(request);
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/api/RepositoryClient.java

@@ -60,6 +60,18 @@ public final class RepositoryClient implements Closeable {
     return new BranchCommandBuilder(clientProvider.getBranchCommand());
   }
 
+  public DeleteRemoteBranchCommandBuilder getDeleteRemoteBranchCommand() {
+    logger.trace("delete branch command");
+
+    return new DeleteRemoteBranchCommandBuilder(clientProvider.getDeleteRemoteBranchCommand());
+  }
+
+  public CheckoutCommandBuilder getCheckoutCommand() {
+    logger.trace("create checkout command");
+
+    return new CheckoutCommandBuilder(clientProvider.getCheckoutCommand());
+  }
+
   public CommitCommandBuilder getCommitCommand() {
     logger.trace("create commit command");
 
@@ -84,6 +96,12 @@ public final class RepositoryClient implements Closeable {
     return new TagCommandBuilder(clientProvider.getTagCommand());
   }
 
+  public MergeCommandBuilder getMergeCommand() {
+    logger.trace("create merge command");
+
+    return new MergeCommandBuilder(clientProvider.getMergeCommand());
+  }
+
   public File getWorkingCopy() {
     return clientProvider.getWorkingCopy();
   }

scm-test/src/main/java/sonia/scm/repository/client/spi/CheckoutCommand.java

@@ -0,0 +1,35 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public interface CheckoutCommand {
+
+  void checkout(String name) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/DeleteRemoteBranchCommand.java

@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import java.io.IOException;
+
+public interface DeleteRemoteBranchCommand {
+
+  void delete(String name) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/MergeCommand.java

@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import sonia.scm.repository.Changeset;
+
+import java.io.IOException;
+
+/**
+ * @since 2.4.0
+ */
+public interface MergeCommand {
+
+  Changeset merge(MergeRequest request) throws IOException;
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/MergeRequest.java

@@ -0,0 +1,102 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.client.spi;
+
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Objects;
+
+/**
+ * @since 2.4.0
+ */
+public final class MergeRequest {
+
+  private String branch;
+  private String message;
+  private FastForwardMode ffMode = FastForwardMode.FF;
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj == null)
+    {
+      return false;
+    }
+
+    if (getClass() != obj.getClass())
+    {
+      return false;
+    }
+
+    final MergeRequest other = (MergeRequest) obj;
+
+    return Objects.equal(branch, other.branch)
+      && Objects.equal(message, other.message);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hashCode(branch, message);
+  }
+
+  public void reset() {
+    this.branch = null;
+    this.message = null;
+  }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+                  .add("branch", branch)
+                  .add("message", message)
+                  .toString();
+  }
+
+  public void setBranch(String branch) {
+    this.branch = branch;
+  }
+
+  public void setMessage(String message) {
+    this.message = message;
+  }
+
+  public void setFfMode(FastForwardMode ffMode) {
+    this.ffMode = ffMode;
+  }
+
+  String getBranch() {
+    return branch;
+  }
+
+  String getMessage() {
+    return message;
+  }
+
+  public FastForwardMode getFfMode() {
+    return ffMode;
+  }
+
+  public enum FastForwardMode {
+    FF_ONLY, FF, NO_FF
+  }
+}

scm-test/src/main/java/sonia/scm/repository/client/spi/RepositoryClientProvider.java

@@ -87,6 +87,14 @@ public abstract class RepositoryClientProvider implements Closeable
     throw new ClientCommandNotSupportedException(ClientCommand.BRANCH);
   }
 
+  public DeleteRemoteBranchCommand getDeleteRemoteBranchCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.DELETE_REMOTE_BRANCH);
+  }
+
+  public CheckoutCommand getCheckoutCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.CHECKOUT);
+  }
+
   /**
    * Method description
    *
@@ -131,6 +139,10 @@ public abstract class RepositoryClientProvider implements Closeable
     throw new ClientCommandNotSupportedException(ClientCommand.TAG);
   }
 
+  public MergeCommand getMergeCommand() {
+    throw new ClientCommandNotSupportedException(ClientCommand.MERGE);
+  }
+
   /**
    * Returns the working copy of the repository client.
    *

scm-ui/ui-webapp/src/repos/components/form/repositoryValidation.test.ts

@@ -37,7 +37,7 @@ describe("repository name validation", () => {
   });
 
   it("should allow same names as the backend", () => {
-    const validPaths = ["scm", "s", "sc", ".hiddenrepo", "b.", "...", "..c", "d..", "a..c"];
+    const validPaths = ["scm", "scm.gitz", "s", "sc", ".hiddenrepo", "b.", "...", "..c", "d..", "a..c"];
 
     validPaths.forEach(path => expect(validator.isNameValid(path)).toBe(true));
   });
@@ -91,7 +91,8 @@ describe("repository name validation", () => {
       "a/..b",
       "scm/main",
       "scm/plugins/git-plugin",
-      "scm/plugins/git-plugin"
+      "scm/plugins/git-plugin",
+      "scm.git"
     ];
 
     invalidPaths.forEach(path => expect(validator.isNameValid(path)).toBe(false));

scm-ui/ui-webapp/src/repos/components/form/repositoryValidation.ts

@@ -24,7 +24,7 @@
 
 import { validation } from "@scm-manager/ui-components";
 
-const nameRegex = /(?!^\.\.$)(?!^\.$)(?!.*[\\\[\]])^[A-Za-z0-9\.][A-Za-z0-9\.\-_]*$/;
+const nameRegex = /(?!^\.\.$)(?!^\.$)(?!.*[.]git$)(?!.*[\\\[\]])^[A-Za-z0-9\.][A-Za-z0-9\.\-_]*$/;
 
 export const isNameValid = (name: string) => {
   return nameRegex.test(name);

scm-webapp/pom.xml

@@ -324,7 +324,7 @@
     <dependency>
       <groupId>net.java.dev.jna</groupId>
       <artifactId>jna</artifactId>
-      <version>5.5.0</version>
+      <version>5.6.0</version>
     </dependency>
 
     <!-- test scope -->
@@ -675,7 +675,7 @@
 
   <properties>
     <scm.stage>DEVELOPMENT</scm.stage>
-    <scm.home>target/scm-it</scm.home>
+    <scm.home>${project.parent.build.directory}/scm-it</scm.home>
     <environment.profile>default</environment.profile>
     <jjwt.version>0.11.2</jjwt.version>
     <selenium.version>2.53.1</selenium.version>
@@ -814,7 +814,7 @@
               <systemProperties>
                 <systemProperty>
                   <name>scm.home</name>
-                  <value>target/scm-it</value>
+                  <value>${scm.home}</value>
                 </systemProperty>
                 <systemProperty>
                   <name>scm.stage</name>
@@ -903,7 +903,7 @@
               <systemProperties>
                 <systemProperty>
                   <name>scm.home</name>
-                  <value>target/scm-it</value>
+                  <value>${scm.home}</value>
                 </systemProperty>
               </systemProperties>
               <jettyXml>${project.basedir}/src/main/conf/jetty.xml</jettyXml>