Currently using the git integration UI, git tries to push commits before testing if a password was entered. A test should be carried to make sure both fields have been entered before form submission.

• VSCode Version: 1.9.1
• OS Version: Ubuntu 16.04 LTS

Steps to Reproduce:

1. Clone a repository eg. git clone https://github.com/Microsoft/vscode.git
2. Make changes, then try to push via the git tab in the left bar
3. Enter GitHub username
4. Leave password field blank
5. Click OK button.
6. Form should submit, but fail to push commits because password field was empty