flush stdin before asking for input

[dirk-thomas]

Same as ros-infrastructure/bloom#249.

@wjwwood Please review.

[wjwwood]

So I noticed in bloom that sometimes the messages which are printed to stdout before one of these prompts never gets displayed. I'm not sure I can reproduce it, but it has definitely happened.

[dirk-thomas]

But do you think it is related to the stdin flushing?

[wjwwood]

I do actually, this is an example of what I am talking about:

==> Generating pull request to distro file located at 'https://raw.github.com/ros/rosdistro/master/hydro/distribution.yaml'
Would you like to add source information for this repository? [Y/n]? n
Would you like to add a maintenance status for this repository? [Y/n]?
Please enter a maintenance status.
Valid maintenance statuses:
- developed: active development is in progress
Status:

There should be two other - prefixed options before the Status: line.

Maybe we should flush stdout before truncating the stdin? I can try that locally and see if that make a difference.

[dirk-thomas]

Actually shouldn't this line be:

tcflush(sys.stdin, TCIFLUSH)

[dirk-thomas]

@wjwwood Can you please give it a try with my previous comment on changing TCIOFLUSH to TCIFLUSH?

[wjwwood]

I'll give it a try now.

[wjwwood]

+1