[libgit2-glib] Added ggit_commit_amend

[Jesse van den Kieboom <jessevdk src gnome org>]

commit ae3eea892d27aaa70b068bc8d7e5e5c7a7f2e5a2
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Tue Jun 24 17:29:47 2014 +0200

    Added ggit_commit_amend

 libgit2-glib/ggit-commit.c |   60 ++++++++++++++++++++++++++++++++++++++++++++
 libgit2-glib/ggit-commit.h |    9 ++++++
 2 files changed, 69 insertions(+), 0 deletions(-)
---
diff --git a/libgit2-glib/ggit-commit.c b/libgit2-glib/ggit-commit.c
index 0c41e15..84d7051 100644
--- a/libgit2-glib/ggit-commit.c
+++ b/libgit2-glib/ggit-commit.c
@@ -486,4 +486,64 @@ ggit_commit_get_nth_ancestor (GgitCommit  *commit,
        return _ggit_commit_wrap (ancestor, TRUE);
 }
 
+/**
+ * ggit_commit_amend:
+ * @commit: a #GgitCommit.
+ * @update_ref: (allow-none): name of the reference to update.
+ * @author: author signature.
+ * @committer: committer signature (and time of commit).
+ * @message_encoding: (allow-none): message encoding.
+ * @message: commit message.
+ * @tree: the tree of objects to commit.
+ * @error: a #GError for error reporting, or %NULL.
+ *
+ * Amend an existing commit. If @update_ref is not %NULL, the given reference will
+ * be updated to point to the newly created commit. Use "HEAD" to update the
+ * HEAD of the current branch and make it point to this commit.
+ *
+ * If @message_encoding is set to %NULL, "UTF-8" encoding is assumed for the
+ * provided @message. Note that @message will not be cleaned up automatically.
+ * You can use #ggit_message_prettify to do this yourself if needed.
+ *
+ * Returns: the #GgitOId of the created commit object, or %NULL in case of an error.
+ *
+ */
+GgitOId *
+ggit_commit_amend (GgitCommit      *commit,
+                   const gchar     *update_ref,
+                   GgitSignature   *author,
+                   GgitSignature   *committer,
+                   const gchar     *message_encoding,
+                   const gchar     *message,
+                   GgitTree        *tree,
+                   GError         **error)
+{
+       gint ret;
+       git_oid oid;
+
+       g_return_val_if_fail (GGIT_IS_COMMIT (commit), NULL);
+       g_return_val_if_fail (GGIT_IS_SIGNATURE (author), NULL);
+       g_return_val_if_fail (GGIT_IS_SIGNATURE (committer), NULL);
+       g_return_val_if_fail (message != NULL, NULL);
+       g_return_val_if_fail (GGIT_IS_TREE (tree), NULL);
+       g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+       ret = git_commit_amend (&oid,
+                                _ggit_native_get (commit),
+                                update_ref,
+                                _ggit_native_get (author),
+                                _ggit_native_get (committer),
+                                message_encoding,
+                                message,
+                                _ggit_native_get (tree));
+
+       if (ret != GIT_OK)
+       {
+               _ggit_error_set (error, ret);
+               return NULL;
+       }
+
+       return _ggit_oid_wrap (&oid);
+}
+
 /* ex:set ts=8 noet: */
diff --git a/libgit2-glib/ggit-commit.h b/libgit2-glib/ggit-commit.h
index 71c3e5f..d1a7635 100644
--- a/libgit2-glib/ggit-commit.h
+++ b/libgit2-glib/ggit-commit.h
@@ -100,6 +100,15 @@ GgitCommit          *ggit_commit_get_nth_ancestor     (GgitCommit        *commit
                                                        guint              n,
                                                        GError           **error);
 
+GgitOId             *ggit_commit_amend                (GgitCommit        *commit,
+                                                       const gchar       *update_ref,
+                                                       GgitSignature     *author,
+                                                       GgitSignature     *committer,
+                                                       const gchar       *message_encoding,
+                                                       const gchar       *message,
+                                                       GgitTree          *tree,
+                                                       GError           **error);
+
 G_END_DECLS
 
 #endif /* __GGIT_COMMIT_H__ */