Focused tab (shrink) has broken border

[usernamehw]

Issue Type: Bug

1. Settings => "workbench.editor.tabSizing": "shrink",
2. Command => Toggle Tab Key Moves Focus Ctrl+M
3. Tab until get to tab (no pun intended)

VS Code version: Code 1.26.1 (493869e, 2018-08-16T18:38:57.434Z)
OS version: Windows_NT x64 10.0.17134