Not continuously input the same commands

[tanxiaoning007]

Current behavior
Input date twice, the second result is empty.

Expected behavior
Expect to print the result by every command

environment:

@angular/cli: 1.2.1
node: 8.1.4
os: win32 x64
@angular/animations: 4.3.0
@angular/common: 4.3.0
@angular/compiler: 4.3.0
@angular/core: 4.3.0
@angular/forms: 4.3.0
@angular/http: 4.3.0
@angular/language-service: 4.3.0
@angular/platform-browser: 4.3.0
@angular/platform-browser-dynamic: 4.3.0
@angular/router: 4.3.0
@angular/cli: 1.2.1
@angular/compiler-cli: 4.3.0

[tanxiaoning007]

Here is my fixed

[cagataycivici]

Fixed via #3733