fix($http): ensure case-insens. header overriding

[caiotoon]

If user send content-type header, both content-type and default
Content-Type headers were sent. Now default header overriding is
case-insensitive.

As per RFC 2616, "[header] Field
names are case-insensitive".

Before this fix, the following test would fail:

it('should override default headers with custom in a case insensitive manner', function() {
  $httpBackend.expect('POST', '/url', 'messageBody', function(headers) {
    return headers['accept'] == 'Rewritten' &&
           headers['content-type'] == 'Rewritten' &&
           headers['Accept'] === undefined &&
           headers['Content-Type'] === undefined;
  }).respond('');

  $http({url: '/url', method: 'POST', data: 'messageBody', headers: {
    'accept': 'Rewritten',
    'content-type': 'Rewritten'
  }});
  $httpBackend.flush();
});

[pkozlowski-opensource]

This is valuable change and improves existing functionality but in terms of implementation we could probably save some bytes. @caiotoon could you try to have another implementation and see if this couldn't be simplified / made smaller? Let me know if you need any help.

[pkozlowski-opensource]

• Contributor signed CLA now or in the past (if you just signed, leave a comment here with your real name for cross reference)
• Feature improves existing core functionality
• API is compatible with existing Angular apis and relevant standards (if applicable)
• PR doesn't contain a breaking change
• PR contains unit tests
• PR contains e2e tests (if suitable)
• PR contains documentation update
• PR passes all tests on Travis (sanity)
• PR passes all tests on ci.angularjs.org (cross-browser compatibility)
• PR is rebased against recent master
• PR is squashed into one commit per logical change
• PR's commit messages are descriptive and allows us to autogenerate release notes (required [commit message

[pkozlowski-opensource]

@caiotoon You will need to sign the CLA as well.

[caiotoon]

Hi, @pkozlowski-opensource. Made it a bit smaller at the trade off of performance at some unnecessary loops (as long as I saw, it's not possible to interrupt a forEach). Also removed some variables and a function declaration. Do you have any other suggestion that could make the code smaller without changing code interface?

Regarding the pendencies,

• CLA: Had already signed the CLA. Name is Caio Gomes Cunha.
• PR contains documentation update: there is no need for doc update, as this is the expected behavior. Am I right?
• PR passes all tests on ci.angularjs.org...: it did passed all tests for me (except for those that were already failing on my machine at master code), which are the failing tests?
• PR's commit messages are descriptive...: how could I make it better? I tried to following commit message convetions. And how would I change it? Should I delete the branch, recreate and pull a request once again?

Thanks!

[IgorMinar]

this PR conflicts with bigger changes in #2130

we are going to land #2130 likely today, I'll ping this PR once we do. can you then rebase your PR please?

[caiotoon]

Sure. Just let me know.

[caiotoon]

@IgorMinar any update on this one?

[petebacondarwin]

@caiotoon - #2130 has landed. Can you try to rebase your chanages off master and then force a push back to this branch?

[caiotoon]

@petebacondarwin rebased and resolved. I'm not pretty sure if I did everything right, feel free to instruct further.

[caiotoon]

I'm not pretty sure, but I believe I did something wrong while rebasing and other changes are being included in this commit as it was mine. I'll try to figure out where I messed up rebasing and will commit again. I'll post here when I believe this pull is ready to be accepted.

[caiotoon]

@petebacondarwin it's now properly rebased and resolved. Ready to merge.

[petebacondarwin]

Merged to master at 53359d5.
Just reworking into stable...

[petebacondarwin]

And landed in stable as 25d9f5a

[petebacondarwin]

Thanks @caiotoon for your work and patience!

[caiotoon]

Nice! No problem.