Add getter methods for object owners

You can know access the owning repository of any existing object, or the
repository on which a revision walker is working on.

Signed-off-by: Vicent Marti <tanoku@gmail.com>

src/git/repository.h

@@ -96,7 +96,7 @@ GIT_EXTERN(git_object *) git_object_new(git_repository *repo, git_otype type);
  * @param object Git object to write back
  * @return 0 on success; otherwise an error code
  */
-int git_object_write(git_object *object);
+GIT_EXTERN(int) git_object_write(git_object *object);
 
 /**
  * Get the id (SHA1) of a repository object
@@ -107,7 +107,7 @@ int git_object_write(git_object *object);
  * @param obj the repository object
  * @return the SHA1 id
  */
-const git_oid *git_object_id(git_object *obj);
+GIT_EXTERN(const git_oid *) git_object_id(git_object *obj);
 
 /**
  * Get the object type of an object
@@ -115,7 +115,15 @@ const git_oid *git_object_id(git_object *obj);
  * @param obj the repository object
  * @return the object's type
  */
-git_otype git_object_type(git_object *obj);
+GIT_EXTERN(git_otype) git_object_type(git_object *obj);
+
+/**
+ * Get the repository that owns this object
+ *
+ * @param obj the object
+ * @return the repository who owns this object
+ */
+GIT_EXTERN(git_repository *) git_object_owner(git_object *obj);
 
 /**
  * Free a reference to one of the objects in the repository.

src/git/revwalk.h

@@ -97,6 +97,15 @@ GIT_EXTERN(void) git_revwalk_sorting(git_revwalk *walk, unsigned int sort_mode);
  */
 GIT_EXTERN(void) git_revwalk_free(git_revwalk *walk);
 
+/**
+ * Return the repository on which this walker
+ * is operating.
+ *
+ * @param walk the revision walker
+ * @return the repository being walked
+ */
+GIT_EXTERN(git_repository *) git_revwalk_repository(git_revwalk *walk);
+
 /** @} */
 GIT_END_DECL
 #endif

src/repository.c

@@ -333,6 +333,12 @@ git_otype git_object_type(git_object *obj)
 	return obj->source.raw.type;
 }
 
+git_repository *git_object_owner(git_object *obj)
+{
+	assert(obj);
+	return obj->repo;
+}
+
 git_object *git_object_new(git_repository *repo, git_otype type)
 {
 	git_object *object = NULL;

src/revwalk.c

@@ -80,6 +80,12 @@ void git_revwalk_free(git_revwalk *walk)
 	free(walk);
 }
 
+git_repository *git_revwalk_repository(git_revwalk *walk)
+{
+	assert(walk);
+	return walk->repo;
+}
+
 void git_revwalk_sorting(git_revwalk *walk, unsigned int sort_mode)
 {
 	if (walk->walking)