thodg/libgit2

diff --git a/include/git2/remote.h b/include/git2/remote.h
index 3633501..07cd2e7 100644
--- a/include/git2/remote.h
+++ b/include/git2/remote.h
@@ -610,6 +610,19 @@ GIT_EXTERN(void) git_remote_set_update_fetchhead(git_remote *remote, int value);
  */
 GIT_EXTERN(int) git_remote_is_valid_name(const char *remote_name);
 
+/**
+* Delete an existing persisted remote.
+*
+* All remote-tracking branches and configuration settings
+* for the remote will be removed.
+*
+* once deleted, the passed remote object will be freed and invalidated.
+*
+* @param remote A valid remote
+* @return 0 on success, or an error code.
+*/
+GIT_EXTERN(int) git_remote_delete(git_remote *remote);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/src/remote.c b/src/remote.c
index 31ee977..bdc4791 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -1304,13 +1304,14 @@ static int rename_remote_config_section(
 	if (git_buf_printf(&old_section_name, "remote.%s", old_name) < 0)
 		goto cleanup;
 
-	if (git_buf_printf(&new_section_name, "remote.%s", new_name) < 0)
-		goto cleanup;
+	if (new_name &&
+		(git_buf_printf(&new_section_name, "remote.%s", new_name) < 0))
+			goto cleanup;
 
 	error = git_config_rename_section(
 		repo,
 		git_buf_cstr(&old_section_name),
-		git_buf_cstr(&new_section_name));
+		new_name ? git_buf_cstr(&new_section_name) : NULL);
 
 cleanup:
 	git_buf_free(&old_section_name);
@@ -1743,3 +1744,144 @@ int git_remote_init_callbacks(git_remote_callbacks *opts, unsigned int version)
 		opts, version, git_remote_callbacks, GIT_REMOTE_CALLBACKS_INIT);
 	return 0;
 }
+
+/* asserts a branch.<foo>.remote format */
+static const char *name_offset(size_t *len_out, const char *name)
+{
+	size_t prefix_len;
+	const char *dot;
+
+	prefix_len = strlen("remote.");
+	dot = strchr(name + prefix_len, '.');
+
+	assert(dot);
+
+	*len_out = dot - name - prefix_len;
+	return name + prefix_len;
+}
+
+static int remove_branch_config_related_entries(
+	git_repository *repo,
+	const char *remote_name)
+{
+	int error;
+	git_config *config;
+	git_config_entry *entry;
+	git_config_iterator *iter;
+	git_buf buf = GIT_BUF_INIT;
+
+	if ((error = git_repository_config__weakptr(&config, repo)) < 0)
+		return error;
+
+	if ((error = git_config_iterator_glob_new(&iter, config, "branch\\..+\\.remote")) < 0)
+		return error;
+
+	/* find any branches with us as upstream and remove that config */
+	while ((error = git_config_next(&entry, iter)) == 0) {
+		const char *branch;
+		size_t branch_len;
+
+		if (strcmp(remote_name, entry->value))
+			continue;
+
+		branch = name_offset(&branch_len, entry->name);
+
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf, "branch.%.*s.merge", (int)branch_len, branch) < 0)
+			break;
+
+		if ((error = git_config_delete_entry(config, git_buf_cstr(&buf))) < 0)
+			break;
+
+		git_buf_clear(&buf);
+		if (git_buf_printf(&buf, "branch.%.*s.remote", (int)branch_len, branch) < 0)
+			break;
+
+		if ((error = git_config_delete_entry(config, git_buf_cstr(&buf))) < 0)
+			break;
+	}
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	git_buf_free(&buf);
+	git_config_iterator_free(iter);
+	return error;
+}
+
+static int remove_refs(git_repository *repo, const char *glob)
+{
+	git_reference_iterator *iter;
+	const char *name;
+	int error;
+
+	if ((error = git_reference_iterator_glob_new(&iter, repo, glob)) < 0)
+		return error;
+
+	while ((error = git_reference_next_name(&name, iter)) == 0) {
+		if ((error = git_reference_remove(repo, name)) < 0)
+			break;
+	}
+	git_reference_iterator_free(iter);
+
+	if (error == GIT_ITEROVER)
+		error = 0;
+
+	return error;
+}
+
+static int remove_remote_tracking(git_repository *repo, const char *remote_name)
+{
+	git_remote *remote;
+	int error;
+	size_t i, count;
+
+	/* we want to use what's on the config, regardless of changes to the instance in memory */
+	if ((error = git_remote_load(&remote, repo, remote_name)) < 0)
+		return error;
+
+	count = git_remote_refspec_count(remote);
+	for (i = 0; i < count; i++) {
+		const git_refspec *refspec = git_remote_get_refspec(remote, i);
+
+		/* shouldn't ever actually happen */
+		if (refspec == NULL)
+			continue;
+
+		if ((error = remove_refs(repo, git_refspec_dst(refspec))) < 0)
+			break;
+	}
+
+	git_remote_free(remote);
+	return error;
+}
+
+int git_remote_delete(git_remote *remote)
+{
+	int error;
+	git_repository *repo;
+
+	assert(remote);
+
+	if (!remote->name) {
+		giterr_set(GITERR_INVALID, "Can't delete an anonymous remote.");
+		return -1;
+	}
+
+	repo = git_remote_owner(remote);
+
+	if ((error = remove_branch_config_related_entries(repo,
+		git_remote_name(remote))) < 0)
+		return error;
+
+	if ((error = remove_remote_tracking(repo, git_remote_name(remote))) < 0)
+		return error;
+
+	if ((error = rename_remote_config_section(
+		repo, git_remote_name(remote), NULL)) < 0)
+		return error;
+
+	git_remote_free(remote);
+
+	return 0;
+}
diff --git a/tests/config/config_helpers.c b/tests/config/config_helpers.c
index 53bd945..35da720 100644
--- a/tests/config/config_helpers.c
+++ b/tests/config/config_helpers.c
@@ -35,3 +35,31 @@ void assert_config_entry_value(
 
 	cl_assert_equal_s(expected_value, out);
 }
+
+static int count_config_entries_cb(
+	const git_config_entry *entry,
+	void *payload)
+{
+	int *how_many = (int *)payload;
+
+	GIT_UNUSED(entry);
+
+	(*how_many)++;
+
+	return 0;
+}
+
+int count_config_entries_match(git_repository *repo, const char *pattern)
+{
+	git_config *config;
+	int how_many = 0;
+
+	cl_git_pass(git_repository_config(&config, repo));
+
+	cl_assert_equal_i(0, git_config_foreach_match(
+		config,	pattern, count_config_entries_cb, &how_many));
+
+	git_config_free(config);
+
+	return how_many;
+}
diff --git a/tests/config/config_helpers.h b/tests/config/config_helpers.h
index b887b3d..4406457 100644
--- a/tests/config/config_helpers.h
+++ b/tests/config/config_helpers.h
@@ -7,3 +7,7 @@ extern void assert_config_entry_value(
 	git_repository *repo,
 	const char *name,
 	const char *expected_value);
+
+extern int count_config_entries_match(
+	git_repository *repo,
+	const char *pattern);
diff --git a/tests/network/remote/delete.c b/tests/network/remote/delete.c
new file mode 100644
index 0000000..db55b07
--- /dev/null
+++ b/tests/network/remote/delete.c
@@ -0,0 +1,61 @@
+#include "clar_libgit2.h"
+#include "config/config_helpers.h"
+
+#include "repository.h"
+
+static git_remote *_remote;
+static git_repository *_repo;
+
+void test_network_remote_delete__initialize(void)
+{
+	_repo = cl_git_sandbox_init("testrepo.git");
+
+	cl_git_pass(git_remote_load(&_remote, _repo, "test"));
+}
+
+void test_network_remote_delete__cleanup(void)
+{
+	cl_git_sandbox_cleanup();
+}
+
+void test_network_remote_delete__cannot_delete_an_anonymous_remote(void)
+{
+	git_remote *remote;
+
+	cl_git_pass(git_remote_create_anonymous(&remote, _repo, "git://github.com/libgit2/libgit2", NULL));
+
+	cl_git_fail(git_remote_delete(remote));
+
+	git_remote_free(remote);
+	git_remote_free(_remote);
+}
+
+void test_network_remote_delete__remove_remote_tracking_branches(void)
+{
+	git_reference *ref;
+
+	cl_git_pass(git_remote_delete(_remote));
+	cl_git_fail_with(GIT_ENOTFOUND, git_reference_lookup(&ref, _repo, "refs/remotes/test/master"));
+}
+
+void test_network_remote_delete__remove_remote_configuration_settings(void)
+{
+	cl_assert(count_config_entries_match(_repo, "remote\\.test\\.+") > 0);
+
+	cl_git_pass(git_remote_delete(_remote));
+
+	cl_assert_equal_i(0, count_config_entries_match(_repo, "remote\\.test\\.+"));
+}
+
+void test_network_remote_delete__remove_branch_upstream_configuration_settings(void)
+{
+	assert_config_entry_existence(_repo, "branch.mergeless.remote", true);
+	assert_config_entry_existence(_repo, "branch.master.remote", true);
+
+	cl_git_pass(git_remote_delete(_remote));
+
+	assert_config_entry_existence(_repo, "branch.mergeless.remote", false);
+	assert_config_entry_existence(_repo, "branch.mergeless.merge", false);
+	assert_config_entry_existence(_repo, "branch.master.remote", false);
+	assert_config_entry_existence(_repo, "branch.master.merge", false);
+}