[SCM-530] Add support for git submodules to git SCM provider

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/main/java/org/apache/maven/scm/provider/git/gitexe/command/checkout/GitCheckOutCommand.java

@@ -70,6 +70,7 @@ public ScmResult executeCommand(ScmProviderRepository repo, ScmFileSet fileSet,
         ScmVersion version = parameters.getScmVersion(CommandParameter.SCM_VERSION, null);
         boolean binary = parameters.getBoolean(CommandParameter.BINARY, false);
         boolean shallow = parameters.getBoolean(CommandParameter.SHALLOW, false);
+        boolean recursive = parameters.getBoolean(CommandParameter.RECURSIVE, false);
 
         GitScmProviderRepository repository = (GitScmProviderRepository) repo;
 
@@ -134,11 +135,30 @@ && new File(fileSet.getBasedir(), ".git").exists()
             lastCommandLine = gitCheckout.toString();
         }
 
+        if (recursive) {
+            // and now lets do the git-submodule update
+            Commandline clSubmoduleUpdate = createSubmoduleUpdateCommand(fileSet.getBasedir());
+
+            exitCode = GitCommandLineUtils.execute(clSubmoduleUpdate, stdout, stderr);
+            if (exitCode != 0) {
+                return new CheckOutScmResult(
+                        clSubmoduleUpdate.toString(),
+                        "The git-submodule update command failed.",
+                        stderr.getOutput(),
+                        false);
+            }
+            lastCommandLine = clSubmoduleUpdate.toString();
+        }
+
         // and now search for the files
         GitListConsumer listConsumer = new GitListConsumer(fileSet.getBasedir(), ScmFileStatus.CHECKED_IN);
 
         Commandline gitList = GitListCommand.createCommandLine(repository, fileSet.getBasedir());
 
+        if (recursive) {
+            gitList.createArg().setValue("--recurse-submodules");
+        }
+
         exitCode = GitCommandLineUtils.execute(gitList, listConsumer, stderr);
         if (exitCode != 0) {
             return new CheckOutScmResult(
@@ -163,6 +183,19 @@ public static Commandline createCommandLine(
         return gitCheckout;
     }
 
+    /**
+     * create a git-submodule update command
+     */
+    Commandline createSubmoduleUpdateCommand(File workingDirectory) {
+        Commandline gitSubmoduleUpdate = GitCommandLineUtils.getBaseGitCommandLine(workingDirectory, "submodule");
+
+        gitSubmoduleUpdate.createArg().setValue("update");
+        gitSubmoduleUpdate.createArg().setValue("--init");
+        gitSubmoduleUpdate.createArg().setValue("--recursive");
+
+        return gitSubmoduleUpdate;
+    }
+
     /**
      * create a git-clone repository command
      */
@@ -183,7 +216,7 @@ private Commandline createCloneCommand(
             gitClone.createArg().setValue("1");
         }
 
-        if (version != null && (version instanceof ScmBranch)) {
+        if (version instanceof ScmBranch) {
 
             gitClone.createArg().setValue("--branch");
 

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/java/org/apache/maven/scm/provider/git/gitexe/command/checkout/GitExeCheckOutCommandRecursiveTest.java

@@ -0,0 +1,99 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.maven.scm.provider.git.gitexe.command.checkout;
+
+import java.io.File;
+import java.util.Collections;
+
+import org.apache.maven.scm.ScmFileSet;
+import org.apache.maven.scm.ScmTestCase;
+import org.apache.maven.scm.ScmVersion;
+import org.apache.maven.scm.command.checkout.CheckOutScmResult;
+import org.apache.maven.scm.provider.git.gitexe.command.GitCommandLineUtils;
+import org.apache.maven.scm.provider.git.repository.GitScmProviderRepository;
+import org.apache.maven.scm.repository.ScmRepository;
+import org.codehaus.plexus.util.FileUtils;
+import org.codehaus.plexus.util.cli.CommandLineUtils;
+import org.codehaus.plexus.util.cli.Commandline;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.apache.maven.scm.provider.git.GitScmTestUtils.GIT_COMMAND_LINE;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Wen Wu
+ *
+ */
+public class GitExeCheckOutCommandRecursiveTest extends ScmTestCase {
+    private File workingDirectory;
+
+    private File repo;
+
+    private ScmRepository scmRepository;
+
+    @Before
+    @Override
+    public void setUp() throws Exception {
+        super.setUp();
+
+        workingDirectory = new File("target/checkout-recursive");
+        FileUtils.deleteDirectory(workingDirectory);
+        repo = new File("src/test/resources/repository_submodule");
+
+        scmRepository = getScmManager()
+                .makeScmRepository(
+                        "scm:git:" + repo.toPath().toAbsolutePath().toUri().toASCIIString());
+    }
+
+    @Test
+    public void testCheckoutNoBranch() throws Exception {
+        checkScmPresence(GIT_COMMAND_LINE);
+        CheckOutScmResult result = checkoutRepo(false);
+
+        assertEquals(5, result.getCheckedOutFiles().size());
+
+        // git submodule set-url sub-prj file:///...
+        Commandline cl = GitCommandLineUtils.getBaseGitCommandLine(
+                workingDirectory,
+                "submodule",
+                (GitScmProviderRepository) scmRepository.getProviderRepository(),
+                Collections.emptyMap());
+
+        String repoUrl = repo.toPath().toAbsolutePath().toUri().toASCIIString();
+        cl.createArg().setValue("set-url");
+        cl.createArg().setValue("sub-prj");
+        cl.createArg().setValue(repoUrl);
+
+        CommandLineUtils.StringStreamConsumer stdout = new CommandLineUtils.StringStreamConsumer();
+        CommandLineUtils.StringStreamConsumer stderr = new CommandLineUtils.StringStreamConsumer();
+        GitCommandLineUtils.execute(cl, stdout, stderr);
+
+        result = checkoutRepo(true);
+        assertEquals(9, result.getCheckedOutFiles().size());
+    }
+
+    protected CheckOutScmResult checkoutRepo(boolean recursive) throws Exception {
+        CheckOutScmResult result =
+                getScmManager().checkOut(scmRepository, new ScmFileSet(workingDirectory), (ScmVersion) null, recursive);
+
+        assertResultIsSuccess(result);
+        return result;
+    }
+}

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/HEAD

@@ -0,0 +1 @@
+ref: refs/heads/master

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/config

@@ -0,0 +1,5 @@
+[core]
+	repositoryformatversion = 0
+	filemode = true
+	bare = true
+	ignorecase = true

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/description

@@ -0,0 +1 @@
+Unnamed repository; edit this file to name it for gitweb.

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/info/exclude

@@ -0,0 +1,6 @@
+# git-ls-files --others --exclude-from=.git/info/exclude
+# Lines that start with '#' are comments.
+# For a project mostly in C, the following would be a good set of
+# exclude patterns (uncomment them if you want to use them):
+# *.[oa]
+# *~

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/logs/HEAD

@@ -0,0 +1,4 @@
+0000000000000000000000000000000000000000 c51dcd33e7b71897603c203b5e0afc1d75f70051 Mark Struberg <[email protected]> 1196106917 +0100
+c51dcd33e7b71897603c203b5e0afc1d75f70051 baa229a9193371fad604444f64c4f26f8ff702f3 Mark Struberg <[email protected]> 1197041894 +0100	push
+baa229a9193371fad604444f64c4f26f8ff702f3 1d308c3b92eb0df9c0dc76436d50edfd0ca41d18 Mark Struberg <[email protected]> 1197042012 +0100	push
+92f139dfec4d1dfb79c3cd2f94e83bf13129668b 021d26a81797f675c66ee7f875dcb4255caa6a84 wuwen <[email protected]> 1688375554 +0800	push

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/logs/refs/heads/master

@@ -0,0 +1,4 @@
+0000000000000000000000000000000000000000 c51dcd33e7b71897603c203b5e0afc1d75f70051 Mark Struberg <[email protected]> 1196106917 +0100
+c51dcd33e7b71897603c203b5e0afc1d75f70051 baa229a9193371fad604444f64c4f26f8ff702f3 Mark Struberg <[email protected]> 1197041894 +0100	push
+baa229a9193371fad604444f64c4f26f8ff702f3 1d308c3b92eb0df9c0dc76436d50edfd0ca41d18 Mark Struberg <[email protected]> 1197042012 +0100	push
+92f139dfec4d1dfb79c3cd2f94e83bf13129668b 021d26a81797f675c66ee7f875dcb4255caa6a84 wuwen <[email protected]> 1688375554 +0800	push

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/logs/refs/remotes/origin/master

@@ -0,0 +1 @@
+0000000000000000000000000000000000000000 c51dcd33e7b71897603c203b5e0afc1d75f70051 Mark Struberg <[email protected]> 1196106917 +0100	clone: from /home/msx/tmp/maven-git/repository/.git

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/objects/02/1d26a81797f675c66ee7f875dcb4255caa6a84

@@ -0,0 +1,2 @@
+x
��A
+� E���A�hJ�Uƙ�bRR%���AW�����ֹigå�":�M����	b#��G��0�xꅻ�M'W,$.B#[.yJĮ�Q"��Y�B�Yao�m�G?dշ��?p�?}h�wmC�0yI_M4F��<���L!�~�\7/��ED

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/objects/07/b300aafa39acce00868af0141f75b73cf14664

@@ -0,0 +1 @@
+x
m���0DYۯ��Gba�3�C�ZmPZG�Ӗ�'�]�޽ӝO���z9=������tm�W�l��t47�5mS8�wAXˊ3P�Y�p@pمar�V�tP��%�����Q��]ㆠ�T��VQ3IT�w�
_RE�

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/objects/92/f139dfec4d1dfb79c3cd2f94e83bf13129668b

@@ -0,0 +1 @@
+x
��1�0@Q��;���	!.��	\ǡ�A��=�ly�R��@k����1H�������p�Q(I ��5q��W�j��;\����_�:�y�u����H=}[$D'ߥ�_ؕ�X���Y����<m

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/objects/ba/a229a9193371fad604444f64c4f26f8ff702f3

@@ -0,0 +1 @@
+x
��MN1@a�9����O���XqDZ��ʤ nB����<�~��|��9T�I�K��������ENV��� F��w��IԤ���f*K>b��&E6���e�D������x��9�U����:}����/@�d�TJ���_��͎[��~‡�}����Ƕ���}���jP�

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/refs/heads/master

@@ -0,0 +1 @@
+021d26a81797f675c66ee7f875dcb4255caa6a84

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/refs/remotes/origin/HEAD

@@ -0,0 +1 @@
+ref: refs/remotes/origin/master

maven-scm-providers/maven-scm-providers-git/maven-scm-provider-gitexe/src/test/resources/repository_submodule/refs/remotes/origin/master

@@ -0,0 +1 @@
+c51dcd33e7b71897603c203b5e0afc1d75f70051