[SOLVED] TFPHTTPClient doesn't work with HTTP response 206 Partial Contect ?

[krexon]

I had never any problems with TFPHTTPClient.
Until now
Response of server is 206 (Partial Content). It is outside of my control. I don't use range.
I can't get JSON response body. Instead of JSON, I receive only 3 chars: %1F%3F%08 (unit separator, question mark, backspace).

What to do with this problem?

[Thaddy]

What to do? Show code that reproduces it. (And your FPC version, Lazarus version and platform/OS)

[krexon]

It's simple HTTP POST. I used it several times and I had no problems when there was response code '200 OK'. For the first time I came across that server server response is '206 Partial Content'. In this case TFPHTTPClient can't get proper response body.

Code: Pascal  [Select][+][-]

1. uses ..., fphttpclient, opensslsockets, ...
2.  
3. with TFPHTTPClient.Create(nil) do
4.   try
5.       AddHeader('Content-Type', 'application/json; charset=UTF-8');
6.       AllowRedirect := True;
7.       RequestBody := TStringStream.Create('{JSON}');
8.       Memo.Lines.Add(Post('https://url'));
9.   finally
10.     RequestBody.Free;
11.     Free;
12.   end;
13.  

[Handoko]

Maybe it is the SSL issue which discussed recently:

https://forum.lazarus.freepascal.org/index.php/topic,39206.msg308413.html#msg308413

[krexon]

No, it's not SSL problem. Everything works fine, except this one case.
Other requests (GET and POST) to the same server, but different endpoints, works fine.

[trev]

I've only ever seen HTTP 206 code responses for range requests. What is the web server software being used which gives the 206 responses? I suspect a bug...

[krexon]

I don't know what web server is there.
When I make the same request in different software (i.e. Visual Studio Code), there is also response with code 206, but there is also proper JSON in response body.

EDIT:
I tested it with standard HttpClient in Delphi 10.3.2 and I get proper JSON response. Of course response code is 206

EDIT2:
I used Indy in Lazarus and response is the same like with fphttpclient (only 3 chars)

EDIT3:
I made simple console application in Lazarus to easy compile with different version of fpc. After compiling program with FPC version I use now 3.3.1 rev 43202 I saw in console that response is much longer than 3 chars. It is:

Code: Pascal  [Select][+][-]

1.       íýGŽ$IŇĽ˙_% kK?t9÷]´g 3˛"#'ČE"P°t7"┼yŔÍ<?DÜ˝ŕîYQžé'?¬* 6?XD¨¨ą«ë#ęfËĐ┼ć'
   !0B?J/?"JÚa<'Ą┼(!? 'Úp<[%"p3qYBa:'47"ÓŢż4?o"XçJĆÂ]˙îR˙ŃţÄeĆd&Ívn¸cď9t*Mę(_ŻĄÖ2Wü!Â"Ĺ (Ä3/'+\Ą|˙ÄeÖ¨|('"/ŤXl7Uú|1ë˙żZŚ┼ă
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2. ÄÁŽ?ŕtÍŻú?Î?mŰ?v
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3. vËÝr÷žÔ¬p
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EDIT4:
Finally I managed to make it work
I added request header and it returns proper JSON in body

Code: Pascal  [Select][+][-]

1. xxx-language : en-GB

I don't know why it has be added only in lazarus and not elsewhere.