In SKARA-1854, we introduced a method GitRepository#isEmptyCommit. In addition, the git show command includes the option '--diff-merges=dense-combined' in git 2.30.0. However, this option is not available in old versions of git. To ensure compatibility with old versions of Git, we should replace '--diff-merges=dense-combined' with the '--cc' option.

References:
[1]https://git-scm.com/docs/git-show/2.29.0
[2]https://git-scm.com/docs/git-show/2.30.0