Pulling local-only branches merges first available branch

[antplant]

Creating a local branch via shell and then attempting to "Pull" it via the GitHub client causes the "first" remote branch to be merged (alphabetically, as far as I can tell).

My assumption is that this is a bug as it seems pretty dangerous. The option to Pull should probably be greyed out (or an error prompt displayed when there's no matching remote branch).

Raised with GitHub support.