I am using below request through chrome advance rest client plugin to upload a chatter with file content and getting exception as 

Error Message: 

[{"errorCode":"POST_BODY_PARSE_ERROR","message":"Binary data included but file attachment information is missing. If providing rich JSON/XML input in multipart REST, make sure to include Content-Type header in the part."}]


Status
400 Bad Request Show explanation Loading time: 1096
Request headers
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36
Origin: chrome-extension://hgmloofddffdnphfgcellkdfbfbjeloo
Authorization: OAuth 00Do0000000Hb0Q!ARkAQPLN0mHGN0vx_id5xe20TIdWilHpKNKxI8luXDURBCpLN8IFam_ga1F8Mok_o6LNQCgB.5ah8WyKng.P1ZmLRbu5oRzo
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary3n9vu9ZOkCPW4HAw
Accept: */*
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Cookie: com.salesforce.LocaleInfo=us; oinfo="c3RhdHVzPURFTU8mdHlwZT0yJm9pZD0wMERmMDAwMDAwM2JITEE="; __cfduid=d5fc50ea917b08b8c4d0764c74aa205f61406140518228; lp=%7B%7D; rememberUn=false; embeddedcomponentcalloutcookie=1; BrowserId=BGaoKzO_QBiyAUpoxbU4pA; sfdc_lv2="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"; disco=o:00Do0000000Hb0Q:005o0000000HzDo:0; autocomplete=1; sid=00Do0000000Hb0Q!ARkAQPLN0mHGN0vx_id5xe20TIdWilHpKNKxI8luXDURBCpLN8IFam_ga1F8Mok_o6LNQCgB.5ah8WyKng.P1ZmLRbu5oRzo; sid_Client=0000000HzDo0000000Hb0Q; clientSrc=59.89.147.242; inst=APPo; oid=00Do0000000Hb0Q; setupopen=; JSESSIONID=7ow2vu2764kwr33z8gabnyc7; lastlist="/a09?fcf=00Bo0000000U2zz&rolodexIndex=-1&page=1"; webact=%7B%22l_vdays%22%3A1%2C%22l_visit%22%3A1408984740028%2C%22session%22%3A1408989139956%2C%22l_search%22%3A%22%22%2C%22l_dtype%22%3A%22%22%2C%22l_page%22%3A%22SFDC%3Aen%3Aa0ao0000002h8tu%22%2C%22counter%22%3A22%2C%22pv%22%3A8%2C%22f_visit%22%3A1404841447432%2C%22version%22%3A%22w172.1%22%2C%22d%22%3A%2270130000000sUW0%22%2C%22l_cloud%22%3A%22No%20Cloud%22%2C%22seg%22%3A%22customer%3Aus%22%2C%22customer%22%3A1405964202516%7D; s_sess=%20s_ppv_x%3D%3B%20s_cc%3Dtrue%3B%20s_sq%3D%3B%20s_ppv%3D78%257C0%3B; s_vi=[CS]v1|29DE16F5054892B0-40000100C0008275[CE]
Response headers
Date: Mon, 25 Aug 2014 18:31:44 GMT
Cache-Control: private
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked

Below is the request description


POST URL:

https://na17.salesforce.com/services/data/v29.0/chatter/feeds/record/a07o000000097sGAAQ/feed-items

Auth Header

Authorization: OAuth <SESSION_ID>

Request Body

{ 
   "body":
   {
      "messageSegments" : [
      {
         "type" : "Text", 
         "text" : "Please accept this receipt."
      }
      ]
   }, 
   "attachment": 
   {
      "attachmentType" : "NewFile",
      "description": "Receipt for expenses",
      "title" : "a.png"
   },
   "feedElementType" :"FeedItem",
   "subjectId" : "005o0000000HzDo"
}

Uploading an image file with name as "feedItemFileUpload".

This looks like a common problem. I am able to post chatter with links and all but not working only in case of files. Thanks for help in advance.