Fix [] was being escaped in query key position

[Lonami]

What do these changes do?

These changes fix a bug where [] was being escaped when used in the key of queries, namely:

def test_with_query_no_escape_braces():
    url = URL("http://example.com/get")
    url2 = url.with_query([("a[]", "3"), ("a[]", "4")])
    assert str(url2) == "http://example.com/get?a[]=3&a[]=4"

Are there changes in behavior for the user?

Yes, if users were relying on unintended, buggy behaviour ([] being escaped) this change may cause issues in their code.

Related issue number

None as far as I know.

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• Add a new news fragment into the CHANGES folder
  • name it <issue_id>.<type> (e.g. 588.bugfix)
  • if you don't have an issue_id change it to the pr id after creating the PR
  • ensure type is one of the following:
    • .feature: Signifying a new feature.
    • .bugfix: Signifying a bug fix.
    • .doc: Signifying a documentation improvement.
    • .removal: Signifying a deprecation or removal of public API.
    • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: Fix issue with non-ascii contents in doctest text files.

[codecov]

Codecov Report

Merging #445 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #445   +/-   ##
=======================================
  Coverage   99.24%   99.25%           
=======================================
  Files           2        2           
  Lines         664      667    +3     
  Branches      152      152           
=======================================
+ Hits          659      662    +3     
  Misses          5        5           

Impacted Files	Coverage Δ
yarl/__init__.py	99.00% <100.00%> (+<0.01%)	⬆️

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[Lonami]

No idea if the version will be 1.4.3, I used that because the last released one according to https://github.com/aio-libs/yarl/blob/master/CHANGES.rst (as of 2311d02) is 1.4.2. Perhaps it deserves a minor bump even though it's a bug-fix patch because it could potentially disrupt users?

[Lonami]

Another bump for the weekend? (Forgot to do it yesterday.)

[webknjaz]

Do you mind also referencing an RFC document that specifies this?

[Lonami]

I do not have any RFC on this, I only wrote this based on what you said in #443 (comment).

web-browsers use varname[] format for arrays

[webknjaz]

So I've done some research and it turns out I was wrong. The square brackets are supposed to be encoded:

• https://stackoverflow.com/a/1688642/595220
• https://stackoverflow.com/a/1016737/595220

PHP hack uses them to turn input values into arrays but the client-side still encodes them.

I've checked it in Chrome and verified that it does encode []. That being said, raw [/] are only allowed as a part of the host section to represent IPv6 addresses.

[Lonami]

Okay, thanks for the investigation. So there's nothing for me to fix in #443 with regards to this and [] should be escaped.