Question UnityWebRequest seems to be including the content-length header in GET requests on iOS

Hi,

I'm currently creating a simple script which fetches a static json file from a website.

Code (CSharp):

1.  
2. public class UpdateAPI
3. {
4.     public virtual async Task<string> VersionCheck(string url)
5.     {
6.         using (UnityWebRequest webRequest = UnityWebRequest.Get(url))
7.         {
8.             Debug.Log($"[Web API]: Querying API [{url}]");
9.             await webRequest.SendWebRequest();
10.             Debug.Log($"[Web API]: HTTP {webRequest.responseCode}");
11.  
12.             if (webRequest.responseCode != 200)
13.             {
14.                 Debug.LogError("[Web API]: There was a problem fetching version data.");
15.                 Debug.LogError(webRequest.error);
16.                 Debug.LogError(webRequest.downloadHandler.text);
17.                 return null;
18.             }
19.             string response = webRequest.downloadHandler.text;
20.             Debug.Log($"[Web API]: RS {response}");
21.             return response;
22.         }
23.     }
24. }
25.  

Invoking this against the server which hosts the json file returns 400 (Bad Request) every time I call it from an iOS device, however it returns the file if I call it from the editor or from Android

I installed Charles on my PC and enabled SSL proxy to verify what the issue may have been and noticed that the requests from my test devices are including the "Content-Length" header, despite being GET requests with no body.

Attempted to replicate the issue using postman and was able to get the server to return a 400 (Bad Request) just by adding the content-length header.

As a work around I thought about deleting the content-length header, but I wasn't able to find a way to remove headers, just overwrite them with some limitations...

Does anyone know of a way to sort this out?

I did find an issue which may have introduced this behaviour:
https://issuetracker.unity3d.com/is...ngth-when-uploading-data-using-the-get-method

* Using Unity2021.3.9f, due to library dependencies in my project, It may not be feasible to update to a different major release

 

Here you go:
note: redacted origin IP address and project name from the user-agent

PC (Unity Editor):

Code (csharp):

1.  {
2.   "args": {},
3.   "headers": {
4.     "Accept": "*/*",
5.     "Accept-Encoding": "deflate, gzip",
6.     "Host": "httpbin.org",
7.     "User-Agent": "UnityPlayer/2021.3.9f1 (UnityWebRequest/1.0, libcurl/7.80.0-DEV)",
8.     "X-Amzn-Trace-Id": "Root=1-6503a9da-59c0a7705b46535579d6d5e7",
9.     "X-Unity-Version": "2021.3.9f1"
10.   },
11.   "origin": "***REDACTED***",
12.   "url": "https://httpbin.org/get"
13. }

Android:

Code (csharp):

1.  
2.  {
3.   "args": {},
4.   "headers": {
5.     "Accept": "*/*",
6.     "Accept-Encoding": "deflate, gzip",
7.     "Host": "httpbin.org",
8.     "User-Agent": "UnityPlayer/2021.3.9f1 (UnityWebRequest/1.0, libcurl/7.80.0-DEV)",
9.     "X-Amzn-Trace-Id": "Root=1-6503ad9a-1c37f45d71363c906c3228db",
10.     "X-Unity-Version": "2021.3.9f1"
11.   },
12.   "origin": "***REDACTED***",
13.   "url": "https://httpbin.org/get"
14. }
15.  

iOS:

Code (csharp):

1.  
2. {
3.   "args": {},
4.   "headers": {
5.    "Accept": "*/*",
6.    "Accept-Encoding": "gzip, deflate, br",
7.    "Accept-Language": "en-US,en;q=0.9",
8.    "Content-Length": "0",
9.    "Host": "httpbin.org",
10.    "User-Agent": "***REDACTED***/0 CFNetwork/1402.0.8 Darwin/22.2.0",
11.    "X-Amzn-Trace-Id": "Root=1-6503ab4c-228bf2cf1228bec122c6aadc",
12.    "X-Unity-Version": "2021.3.9f1"
13.   },
14.   "origin": "***REDACTED***",
15.  
16.   "url": "https://httpbin.org/get"
17. }
18.  

 

Not sure if I did it correctly but: IN-54957