[ostree] libostree: add new API ostree_repo_write_commit_with_time

[Giuseppe Scrivano <gscrivano src gnome org>]

commit 14ffd7022a8c840f277c81e53864be4ea5fabacb
Author: Giuseppe Scrivano <gscrivan redhat com>
Date:   Mon Nov 9 10:16:55 2015 +0000

    libostree: add new API ostree_repo_write_commit_with_time
    
    It extends ostree_repo_write_commit as it permits to override the
    commit timestamp.
    
    Signed-off-by: Giuseppe Scrivano <gscrivan redhat com>

 doc/ostree-sections.txt            |    1 +
 src/libostree/ostree-repo-commit.c |   51 ++++++++++++++++++++++++++++++++---
 src/libostree/ostree-repo.h        |   11 ++++++++
 3 files changed, 58 insertions(+), 5 deletions(-)
---
diff --git a/doc/ostree-sections.txt b/doc/ostree-sections.txt
index ff512e4..aecaa56 100644
--- a/doc/ostree-sections.txt
+++ b/doc/ostree-sections.txt
@@ -282,6 +282,7 @@ ostree_repo_write_directory_to_mtree
 ostree_repo_write_archive_to_mtree
 ostree_repo_write_mtree
 ostree_repo_write_commit
+ostree_repo_write_commit_with_time
 ostree_repo_read_commit_detached_metadata
 ostree_repo_write_commit_detached_metadata
 OstreeRepoCheckoutMode
diff --git a/src/libostree/ostree-repo-commit.c b/src/libostree/ostree-repo-commit.c
index 7cc3e27..732bbd0 100644
--- a/src/libostree/ostree-repo-commit.c
+++ b/src/libostree/ostree-repo-commit.c
@@ -1969,11 +1969,55 @@ ostree_repo_write_commit (OstreeRepo      *self,
                           GError         **error)
 {
   gboolean ret = FALSE;
+  GDateTime *now = NULL;
+
+  now = g_date_time_new_now_utc ();
+  ret = ostree_repo_write_commit_with_time (self,
+                                          parent,
+                                          subject,
+                                          body,
+                                          metadata,
+                                          root,
+                                          GUINT64_TO_BE (g_date_time_to_unix (now)),
+                                          out_commit,
+                                          cancellable,
+                                          error);
+  g_date_time_unref (now);
+  return ret;
+}
+
+/**
+ * ostree_repo_write_commit_with_time:
+ * @self: Repo
+ * @parent: (allow-none): ASCII SHA256 checksum for parent, or %NULL for none
+ * @subject: Subject
+ * @body: (allow-none): Body
+ * @metadata: (allow-none): GVariant of type a{sv}, or %NULL for none
+ * @root: The tree to point the commit to
+ * @out_commit: (out): Resulting ASCII SHA256 checksum for commit
+ * @cancellable: Cancellable
+ * @error: Error
+ *
+ * Write a commit metadata object, referencing @root_contents_checksum
+ * and @root_metadata_checksum.
+ */
+gboolean
+ostree_repo_write_commit_with_time (OstreeRepo      *self,
+                                    const char      *parent,
+                                    const char      *subject,
+                                    const char      *body,
+                                    GVariant        *metadata,
+                                    OstreeRepoFile  *root,
+                                    guint64          time,
+                                    char           **out_commit,
+                                    GCancellable    *cancellable,
+                                    GError         **error)
+{
+  gboolean ret = FALSE;
   g_autofree char *ret_commit = NULL;
   g_autoptr(GVariant) commit = NULL;
   g_autoptr(GVariant) new_metadata = NULL;
   g_autofree guchar *commit_csum = NULL;
-  GDateTime *now = NULL;
   OstreeRepoFile *repo_root = OSTREE_REPO_FILE (root);
 
   g_return_val_if_fail (subject != NULL, FALSE);
@@ -1983,13 +2027,12 @@ ostree_repo_write_commit (OstreeRepo      *self,
                                    cancellable, error))
     goto out;
 
-  now = g_date_time_new_now_utc ();
   commit = g_variant_new ("(@a{sv} ay@a(say)sst ay@ay)",
                           new_metadata ? new_metadata : create_empty_gvariant_dict (),
                           parent ? ostree_checksum_to_bytes_v (parent) : ot_gvariant_new_bytearray (NULL, 0),
                           g_variant_new_array (G_VARIANT_TYPE ("(say)"), NULL, 0),
                           subject, body ? body : "",
-                          GUINT64_TO_BE (g_date_time_to_unix (now)),
+                          GUINT64_TO_BE (time),
                           ostree_checksum_to_bytes_v (ostree_repo_file_tree_get_contents_checksum 
(repo_root)),
                           ostree_checksum_to_bytes_v (ostree_repo_file_tree_get_metadata_checksum 
(repo_root)));
   g_variant_ref_sink (commit);
@@ -2003,8 +2046,6 @@ ostree_repo_write_commit (OstreeRepo      *self,
   ret = TRUE;
   ot_transfer_out_value(out_commit, &ret_commit);
  out:
-  if (now)
-    g_date_time_unref (now);
   return ret;
 }
 
diff --git a/src/libostree/ostree-repo.h b/src/libostree/ostree-repo.h
index e67c310..69720a2 100644
--- a/src/libostree/ostree-repo.h
+++ b/src/libostree/ostree-repo.h
@@ -452,6 +452,17 @@ gboolean      ostree_repo_write_commit (OstreeRepo      *self,
                                         GCancellable    *cancellable,
                                         GError         **error);
 
+gboolean      ostree_repo_write_commit_with_time (OstreeRepo      *self,
+                                                  const char      *parent,
+                                                  const char      *subject,
+                                                  const char      *body,
+                                                  GVariant        *metadata,
+                                                  OstreeRepoFile  *root,
+                                                  guint64         time,
+                                                  char           **out_commit,
+                                                  GCancellable    *cancellable,
+                                                  GError         **error);
+
 gboolean      ostree_repo_read_commit_detached_metadata (OstreeRepo      *self,
                                                          const char      *checksum,
                                                          GVariant       **out_metadata,