stop coercing falsy values to null before xhr.send()

[johnhoffman]

This is intended to resolve #11552.

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[johnhoffman]

I signed it!

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request) and all commit authors, but as best as we can tell these commits were authored by someone else. If that's the case, please add them to this pull request and have them confirm that they're okay with these commits being contributed to Google. If we're mistaken and you did author these commits, just reply here to confirm.

[johnhoffman]

I authored the commits.

[samjacobclift]

I've had a little play with this issue. I've created a test I think is valid to check the behaviour.

see: samjacobclift@89ec5af

[pkozlowski-opensource]

@johnhoffman your commit is missing tests so we can't merge it as-is. There also seems to be an issue with the CLA - I suspect you've used a different e-mail / GitHub user name to author the commit and different one to sign the CLA.

@royka would you mind opening a PR with your change to see if the existing test pass? For example - do we need to convert undefined to null?

[samjacobclift]

@pkozlowski-opensource see here #11579

unit tests pass, seems that the e2e don't pass though :(

[googlebot]

CLAs look good, thanks!

[johnhoffman]

I fixed the CLA and updated the PR. Still unable to build angular and run tests on my machine (https://docs.angularjs.org/misc/contribute) so I guess we resort to Travis CI?