Error message on publish drop truncates endpoint name

[bahendri]

I'm using aptly 1.2.0 on Ubuntu 16.04.

While experimenting, I accidentally deleted my aptly configuration file after publishing a snapshot to a custom, file system endpoint.

With the conf files now missing, I correctly received an error message. However, the endpoint name in the error message was truncated strangely. Specifically, the "filesy" was missing from "filesystem".

$ aptly publish list
Published repositories:
  * filesystem:nodesource-nodejs:./xenial [amd64] publishes {main: [nodesource-20180305]: Snapshot from mirror [nodesource]: https://deb.nodesource.com/node_6.x/ xenial}

# Deleted ~/.aptly.conf and /etc/aptly.conf

$ sudo aptly publish drop xenial filesystem:nodesource-nodejs:
ERROR: published local storage stem:nodesource-nodejs not configured

It seems like this is happening in https://github.com/smira/aptly/blob/9cb2a302f8f138dba7887c848f956633f8b3eb01/context/context.go. I'm not sure why it skips over the first 6 characters.

// GetPublishedStorage returns instance of PublishedStorage
func (context *AptlyContext) GetPublishedStorage(name string) aptly.PublishedStorage {

	publishedStorage, ok := context.publishedStorages[name]
	if !ok {
		if name == "" {
			publishedStorage = files.NewPublishedStorage(filepath.Join(context.config().RootDir, "public"), "hardlink", "")
		} else if strings.HasPrefix(name, "filesystem:") {
			params, ok := context.config().FileSystemPublishRoots[name[11:]]
			if !ok {
				Fatal(fmt.Errorf("published local storage %v not configured", name[6:]))
}