[COUCHDB-2295] Connection hangs on document update for multipart/related and transfer encoding chunked request

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Fix Version/s: 1.7.0
• Component/s: HTTP Interface
• Assignee: Unassigned
• Reporter: Alexander Shorin
• Created: 17/Aug/14 12:44
• Updated: 02/Sep/18 06:57
• Resolved: 02/Sep/18 06:57

Description

Script to reproduce:

import pprint
import requests

body = [
    b'--996713c691ec4fd5b717ef2740893b78\r\n',
    b'Content-Type: application/json\r\n',
    b'\r\n',
    b'{"_id": "test","_attachments": {"foo": {"follows": true, "content_type": "text/plain", "length": 12}}}\r\n',
    b'--996713c691ec4fd5b717ef2740893b78\r\n',
    b'Content-Type: text/plain\r\n'
    b'Content-Disposition: attachment;filename="foo"\r\n'
    b'Content-Length: 12\r\n'
    b'\r\n',
    b'Time to Relax!',
    b'--996713c691ec4fd5b717ef2740893b78--\r\n'
]


url = 'http://localhost:5984/db/test'
headers = {
    'Content-Type': 'multipart/related; boundary="996713c691ec4fd5b717ef2740893b78"'
}
resp = requests.put(url, headers=headers, data=iter(body))
pprint.pprint(resp.json())

This runs a request:

PUT /db/test HTTP/1.1
Host: localhost:5984
Accept-Encoding: gzip, deflate
Transfer-Encoding: chunked
User-Agent: python-requests/2.3.0 CPython/3.4.1 Linux/3.15.5-gentoo
Accept: */*
Content-Type: multipart/related; boundary="996713c691ec4fd5b717ef2740893b78"

24
--996713c691ec4fd5b717ef2740893b78

20
Content-Type: application/json

2


68
{"_id": "test","_attachments": {"foo": {"follows": true, "content_type": "text/plain", "length": 14}}}

24
--996713c691ec4fd5b717ef2740893b78

60
Content-Type: text/plain
Content-Disposition: attachment;filename="foo"
Content-Length: 12


e
Time to Relax!
26
--996713c691ec4fd5b717ef2740893b78--

0

But connection hangs: CouchDB thinks that there have to more data while zero length chunk had been send and doesn't reply with anything back to client which had finished the request and awaits for the response.

The problem could be "fixed" by specifying full Content-Length of multipart body in request, which kills all the idea of chunked transfer.

Issue Links

• links to: GitHub Pull Request #36
• links to: GitHub Pull Request #156