thodg/libgit2

diff --git a/include/git2/branch.h b/include/git2/branch.h
index 0c0cc7f..24ea7f7 100644
--- a/include/git2/branch.h
+++ b/include/git2/branch.h
@@ -305,6 +305,19 @@ GIT_EXTERN(int) git_branch_remote_name(
  GIT_EXTERN(int) git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname);
 
 /**
+ * Retrieve the upstream merge of a local branch
+ *
+ * This will return the currently configured "branch.*.merge" for a given
+ * branch. This branch must be local.
+ *
+ * @param buf the buffer into which to write the name
+ * @param repo the repository in which to look
+ * @param refname the full name of the branch
+ * @return 0 or an error code
+ */
+ GIT_EXTERN(int) git_branch_upstream_merge(git_buf *buf, git_repository *repo, const char *refname);
+
+/**
  * Determine whether a branch name is valid, meaning that (when prefixed
  * with `refs/heads/`) that it is a valid reference name, and that any
  * additional branch name restrictions are imposed (eg, it cannot start
diff --git a/src/branch.c b/src/branch.c
index 29ff0b9..e6818a8 100644
--- a/src/branch.c
+++ b/src/branch.c
@@ -468,7 +468,7 @@ cleanup:
 	return error;
 }
 
-int git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname)
+static int git_branch_upstream_with_format(git_buf *buf, git_repository *repo, const char *refname, const char *format, const char *format_name)
 {
 	int error;
 	git_config *cfg;
@@ -480,11 +480,11 @@ int git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *r
 		return error;
 
 	if ((error = git_buf_sanitize(buf)) < 0 ||
-	    (error = retrieve_upstream_configuration(buf, cfg, refname, "branch.%s.remote")) < 0)
+	    (error = retrieve_upstream_configuration(buf, cfg, refname, format)) < 0)
 		return error;
 
 	if (git_buf_len(buf) == 0) {
-		git_error_set(GIT_ERROR_REFERENCE, "branch '%s' does not have an upstream remote", refname);
+		git_error_set(GIT_ERROR_REFERENCE, "branch '%s' does not have an upstream %s", refname, format_name);
 		error = GIT_ENOTFOUND;
 		git_buf_clear(buf);
 	}
@@ -492,6 +492,16 @@ int git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *r
 	return error;
 }
 
+int git_branch_upstream_remote(git_buf *buf, git_repository *repo, const char *refname)
+{
+	return git_branch_upstream_with_format(buf, repo, refname, "branch.%s.remote", "remote");
+}
+
+int git_branch_upstream_merge(git_buf *buf, git_repository *repo, const char *refname)
+{
+	return git_branch_upstream_with_format(buf, repo, refname, "branch.%s.merge", "merge");
+}
+
 int git_branch_remote_name(git_buf *buf, git_repository *repo, const char *refname)
 {
 	git_strarray remote_list = {0};
diff --git a/tests/refs/branches/upstream.c b/tests/refs/branches/upstream.c
index 928a9ff..c94afe9 100644
--- a/tests/refs/branches/upstream.c
+++ b/tests/refs/branches/upstream.c
@@ -71,6 +71,29 @@ void test_refs_branches_upstream__upstream_remote(void)
 	git_buf_dispose(&buf);
 }
 
+void test_refs_branches_upstream__upstream_merge(void)
+{
+	git_reference *branch;
+	git_repository *repository;
+	git_buf buf = GIT_BUF_INIT;
+
+	repository = cl_git_sandbox_init("testrepo.git");
+
+	/* check repository */
+	cl_git_pass(git_reference_lookup(&branch, repository, "refs/heads/test"));
+	cl_git_pass(git_branch_set_upstream(branch, "test/master"));
+
+	assert_config_entry_value(repository, "branch.test.remote", "test");
+	assert_config_entry_value(repository, "branch.test.merge", "refs/heads/master");
+
+	git_reference_free(branch);
+
+	/* check merge branch */
+	cl_git_pass(git_branch_upstream_merge(&buf, repository, "refs/heads/test"));
+	cl_assert_equal_s("refs/heads/master", buf.ptr);
+	git_buf_dispose(&buf);
+}
+
 void test_refs_branches_upstream__upstream_remote_empty_value(void)
 {
 	git_repository *repository;