This PR was merged into the 4.4 branch.Discussion----------[HttpClient] Handle requests with null body| Q             | A| ------------- | ---| Branch?       | 4.4| Bug fix?      | yes| New feature?  | no| Deprecations? | no| Tickets       | /| License       | MIT| Doc PR        | /since#45527 passing null to the `body` parameters leads to an exception (which [breaks async-aws](https://github.com/async-aws/aws/blob/09723ddca29b8d1d522426f81dd422373de1785f/src/Core/src/AbstractApi.php#L157))> Argument#2 ($body) must be of type Closure, null given, called in /home/runner/work/aws/aws/vendor/symfony/http-client/CurlHttpClient.php on line 221In curl client: `null` is not a string and `self::readRequestBody` expects a closure.https://github.com/symfony/symfony/blob/08fa74a16c84895575e305b2a7ee3a03e371f79b/src/Symfony/Component/HttpClient/CurlHttpClient.php#L214-L221In NativeClient, `getBodyAsString` will fail to return `null` because of the `string` return type.Before#45527 null was converted to `""` thanks to the defaultOptions, but this is not the case anymore.In many places, we check if the body is `!== ""` but rarely check if the body is null, this PR restores the original behaviors for the `body` parameters and converts nulls to `""`.Commits-------39aec09 [HttpClient] Handle requests with null body