How can I create an empty commit using libgit2?

Question

I've been looking over the libgit2 C API reference, but I don't see how I could emulate the behaviour of git commit --allow-empty. Does libgit2 have a built-in way to create empty commits? If not, how does git create an empty commit under-the-hood, and how should I go about achieving the same behaviour using libgit2?

Answer 1

Call git_commit_create with the same tree as the parent commit. That is:

// Get parent somehow.
git_commit *parent = ...;

// Use the same tree as the parent.
git_tree *tree;
git_commit_tree(&tree, parent);

// Create the commit.
git_commit_create(..., tree, 1, parent);