System Details

• posh-git version/path: 0.7.1 C:\Program Files\WindowsPowerShell\Modules\posh-git\0.7.1
• PowerShell version: 5.1.16299.98
• git version 2.15.0.windows.1
• OS: Microsoft Windows NT 10.0.16299.0
• default settings, no customisation of posh-git

Issue Description

Given a Git repo with branch B1 being locally and on the remote upstream and branch B2 being only locally and trying to tab complete as follows:

git checkout B<Tab>

Expected Result

Tab completion should show 2 branches to tab complete

B1 B2

Actual Result

Branches that exist locally and on the remote are shown twice:

B1 B1 B2