git-commit-id/git-commit-id-maven-plugin#701: add testcase to demonstrate the issue

Author: TheSnoozer

src/test/java/pl/project13/core/AvailableGitTestRepo.java

@@ -48,7 +48,41 @@ public enum AvailableGitTestRepo {
    */
   WITH_COMMIT_THAT_HAS_TWO_TAGS("src/test/resources/_git_with_commit_that_has_two_tags"),
   ON_A_TAG_DIRTY("src/test/resources/_git_on_a_tag_dirty"),
+  /**
+   * <pre>
+   * * 01ed93c - (11 years ago) any commit, just a readme - Konrad Malawski (HEAD -> master)
+   * * 4ce26eb - (11 years ago) my submodules, yay - Konrad Malawski
+   * </pre>
+   * <pre>
+   * $ git submodule status
+   * -9fd4b69a5ca09b60884d4f8f49ce16ea071077be module1
+   * -9fd4b69a5ca09b60884d4f8f49ce16ea071077be module2
+   * -9fd4b69a5ca09b60884d4f8f49ce16ea071077be module3
+   * -9fd4b69a5ca09b60884d4f8f49ce16ea071077be module4
+   *
+   * $ git config --file .gitmodules --get-regexp '\.url$'
+   * submodule.module1.url /tmp/module1
+   * submodule.module2.url /tmp/module1
+   * submodule.module3.url /tmp/module1
+   * submodule.module4.url /tmp/module1
+   * </pre>
+   */
   WITH_SUBMODULES("src/test/resources/_git_with_submodules"),
+
+  /**
+   * <pre>
+   * 6455ccd - (3 minutes ago) init (HEAD -> master)
+   * </pre>
+   * <pre>
+   * $ git submodule status
+   * 945bfe60e8a3eff168e915c7ba5bac37c9d0165b remote-module (heads/empty-branch)
+   *
+   * $ git submodule foreach --recursive git remote get-url origin
+   * Entering 'remote-module'
+   * git@github.com:git-commit-id/git-test-resources.git
+   * </pre>
+   */
+  WITH_REMOTE_SUBMODULES("src/test/resources/_git_with_remote_submodules"),
   /**
    * <pre>
    * b6a73ed - (HEAD, master) third addition (4 minutes ago) <p>Konrad Malawski</p>

src/test/java/pl/project13/core/GitCommitIdPluginIntegrationTest.java

@@ -1583,6 +1583,35 @@ public void shouldGeneratePropertiesWithMultiplePrefixesAndReactorProject(boolea
     }
   }
 
+  @Test
+  @Parameters(method = "useNativeGit")
+  public void shouldWorkWithRelativeSubmodules(boolean useNativeGit) throws Exception {
+    // given
+    File parentProjectDotGit =
+        createTmpDotGitDirectory(AvailableGitTestRepo.WITH_REMOTE_SUBMODULES);
+    File submoduleDotGitDirectory = parentProjectDotGit.getParentFile().toPath().resolve(
+        "remote-module").resolve(".git").toFile();
+    submoduleDotGitDirectory.getParentFile().mkdir();
+    Files.write(
+        submoduleDotGitDirectory.toPath(),
+        "gitdir: ../.git/modules/remote-module".getBytes()
+    );
+
+
+    GitCommitIdPlugin.Callback cb =
+        new GitCommitIdTestCallback()
+        .setDotGitDirectory(submoduleDotGitDirectory)
+        .setUseNativeGit(useNativeGit)
+        .build();
+    Properties properties = new Properties();
+
+    // when
+    GitCommitIdPlugin.runPlugin(cb, properties);
+
+    // then
+    assertPropertyPresentAndEqual(properties, "git.commit.id.abbrev", "945bfe6");
+  }
+
   @Test
   public void verifyAllowedCharactersForEvaluateOnCommit() {
     Pattern p = GitCommitIdPlugin.allowedCharactersForEvaluateOnCommit;