Invalid encoding of %20 char sequence in $.ajax post, put body

[ermouth]

Description

Seems that jQuery 3 replaces %20 char sequence to + in a request body during PUT and POST. A request like

$.ajax({
  method: 'put', 
  url: '/test/doc', 
  dataType: 'json',
  headers: {'content-type':'application/json'},
  data: JSON.stringify({val:'%20'})
})

actually sends {"val":"+"} in 3.2.1 and 3.3.1, both with Migration tools.

jQuery however 2.x behaves correctly.

Update. Seems the reason is this block https://github.com/jquery/jquery/blob/master/src/ajax.js#L617-L621. It assumes s.contentType is the only source of Content-Type header, but there can be s.headers['content-type'], which later (https://github.com/jquery/jquery/blob/master/src/ajax.js#L648-L650) overrides s.contentType value.

[dmethvin]

I agree with your analysis! If we're letting the header override the setting I guess we should honor both. Would you like to file a pull request?

[ermouth]

Yes, but it may take a time to read all community guides. However hope a fix for this is not urgent )

[Gomathy97]

Hi, is there any update on this?
It would be fine if there’s any alternative
This is creating a major breakage in one of works. It would helpful if you assist at the earliy

[mgol]

@Gomathy97 The summary is in #4123 (comment) & #4123 (comment). We welcome PRs, that's the easiest way to make the fix be available sooner.

[wenz]

I've sent a PR that implements the functionality as suggested in the #4123 discussion; based on the research and code by @ermouth