[SCM-1022] jgit push failure is not failing the build

This closes #203

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gittest/src/main/java/org/apache/maven/scm/provider/git/command/checkin/GitCheckInCommandTckTest.java

@@ -19,11 +19,19 @@
 package org.apache.maven.scm.provider.git.command.checkin;
 
 import java.io.File;
+import java.io.IOException;
 
+import org.apache.maven.scm.PlexusJUnit4TestSupport;
+import org.apache.maven.scm.ScmFileSet;
+import org.apache.maven.scm.command.checkin.CheckInScmResult;
 import org.apache.maven.scm.command.checkout.CheckOutScmResult;
 import org.apache.maven.scm.provider.git.GitScmTestUtils;
 import org.apache.maven.scm.repository.ScmRepository;
 import org.apache.maven.scm.tck.command.checkin.CheckInCommandTckTest;
+import org.codehaus.plexus.util.FileUtils;
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
 
 /**
  * @author <a href="mailto:struberg@yahoo.de">Mark Struberg</a>
@@ -44,4 +52,61 @@ protected CheckOutScmResult checkOut(File workingDirectory, ScmRepository reposi
             GitScmTestUtils.setDefaulGitConfig(workingDirectory);
         }
     }
+
+    @Test
+    public void testUpToDatePush() throws Exception {
+        File checkedOutRepo = getWorkingCopy();
+
+        ScmRepository scmRepository = getScmManager().makeScmRepository(getScmUrl());
+        checkoutRepoInto(checkedOutRepo, scmRepository);
+
+        // Add a default user to the config
+        GitScmTestUtils.setDefaulGitConfig(checkedOutRepo);
+
+        CheckInScmResult result =
+                getScmManager().checkIn(scmRepository, new ScmFileSet(checkedOutRepo), "No change commit message");
+
+        assertResultIsSuccess(result);
+    }
+
+    @Test
+    public void testRejectedNonFastForwardPush() throws Exception {
+        File blockingRepo = PlexusJUnit4TestSupport.getTestFile("target/scm-test/blocking-repo");
+        File rejectedRepo = PlexusJUnit4TestSupport.getTestFile("target/scm-test/rejected-repo");
+
+        ScmRepository scmRepository = getScmManager().makeScmRepository(getScmUrl());
+        checkoutRepoInto(rejectedRepo, scmRepository);
+        checkoutRepoInto(blockingRepo, scmRepository);
+
+        // Add a default user to the config
+        GitScmTestUtils.setDefaulGitConfig(rejectedRepo);
+        GitScmTestUtils.setDefaulGitConfig(blockingRepo);
+
+        ScmFileSet blockingFileSet = createWorkspaceChange(rejectedRepo);
+
+        CheckInScmResult blockingResult = getScmManager().checkIn(scmRepository, blockingFileSet, "Blocking commit");
+        assertResultIsSuccess(blockingResult);
+
+        ScmFileSet rejectedFileSet = createWorkspaceChange(blockingRepo);
+
+        CheckInScmResult checkInScmResult = getScmManager().checkIn(scmRepository, rejectedFileSet, "Rejected commit");
+        assertFalse(
+                "check-in should have been rejected since fast forward was not possible", checkInScmResult.isSuccess());
+    }
+
+    private CheckOutScmResult checkoutRepoInto(File workingCopy, ScmRepository scmRepository) throws Exception {
+        FileUtils.deleteDirectory(workingCopy);
+        workingCopy.mkdir();
+
+        CheckOutScmResult result = getScmManager().checkOut(scmRepository, new ScmFileSet(workingCopy), null);
+
+        assertResultIsSuccess(result);
+        return result;
+    }
+
+    private ScmFileSet createWorkspaceChange(File repo) throws IOException {
+        File beerFile = new File(repo.getAbsolutePath(), "beer.xml");
+        FileUtils.fileWrite(beerFile.getAbsolutePath(), "1 litre");
+        return new ScmFileSet(repo, beerFile.getName());
+    }
 }

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-jgit/src/main/java/org/apache/maven/scm/provider/git/jgit/command/checkin/JGitCheckInCommand.java

@@ -43,7 +43,9 @@
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.UserConfig;
 import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.transport.PushResult;
 import org.eclipse.jgit.transport.RefSpec;
+import org.eclipse.jgit.transport.RemoteRefUpdate;
 
 /**
  * This provider uses the following strategy to discover the committer and author name/mail for a commit:
@@ -139,7 +141,19 @@ protected CheckInScmResult executeCheckInCommand(
                 }
                 RefSpec refSpec = new RefSpec(Constants.R_HEADS + branch + ":" + Constants.R_HEADS + branch);
                 logger.info("push changes to remote... " + refSpec);
-                JGitUtils.push(git, (GitScmProviderRepository) repo, refSpec);
+                Iterable<PushResult> pushResultList = JGitUtils.push(git, (GitScmProviderRepository) repo, refSpec);
+
+                for (PushResult pushResult : pushResultList) {
+                    for (RemoteRefUpdate remoteRefUpdate : pushResult.getRemoteUpdates()) {
+                        if (!isSuccessStatus(remoteRefUpdate.getStatus())) {
+                            return new CheckInScmResult(
+                                    "JGit checkin",
+                                    "The git-push command failed, with status: " + remoteRefUpdate.getStatus(),
+                                    remoteRefUpdate.getMessage(),
+                                    false);
+                        }
+                    }
+                }
             }
 
             return new CheckInScmResult("JGit checkin", checkedInFiles);
@@ -150,7 +164,13 @@ protected CheckInScmResult executeCheckInCommand(
         }
     }
 
+    private boolean isSuccessStatus(RemoteRefUpdate.Status remoteRefUpdateStatus) {
+        return remoteRefUpdateStatus == RemoteRefUpdate.Status.OK
+                || remoteRefUpdateStatus == RemoteRefUpdate.Status.UP_TO_DATE;
+    }
+
     private static final class UserInfo {
+
         final String name;
 
         final String email;