• VSCode Version: 1.15.1
• OS Version: macOS Sierra 10.12.6

Steps to Reproduce:

1. Update workspace settings to something like

{
  "terminal.integrated.env.osx": {
    "PATH": "/home"
  }
}

2. Now open Terminal and look at PATH

echo $PATH
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/home

On Windows, having the same setting will not result in the current PATH being prepended, but instead, just setting the path to whatever is defined in terminal.integrated.env.*

Reproduces without extensions: Yes