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From Sebastian Cohnen <sebastiancoh...@googlemail.com>
Subject Re: Deleted docs can be accidentally resurrected
Date Wed, 18 Nov 2009 23:29:31 GMT
afaik, this behavior is normal. you just created another (and new) resource/document.

have a look (the database test is new and never contained docs with id 'foo' or 'foobar'):

$ curl -X PUT -d '{"_id": "foo", "_rev": "1-967a00dff5e02add41819138abb3284d", "num": 1}'
"http://localhost:5984/test/foo"
{"ok":true,"id":"foo","rev":"2-65371ad05fc99a9b794f68c6003bc8da"}

$ curl -X PUT -d '{"_id": "foobar", "_rev": "4-anythingyouwant", "num": 1}' "http://localhost:5984/test/foobar"
{"ok":true,"id":"foobar","rev":"5-084106c9189a346875996e76c1833630"}


cheers,

tisba / Sebastian

On 18.11.2009, at 23:56, Matt Goodall wrote:

> Hi,
> 
> I swear I've reported this odd behaviour before but I can't find any
> mention of it now ...
> 
> I have some code with a race condition that is caused by what I
> believe is a bug in CouchDB - a deleted document can be updated using
> an old, valid rev.
> 
> If a document has not been deleted then CouchDB correctly returns a
> conflict error if the latest rev is not sent. However, once deleted,
> any rev in the docs history can be sent as the update and, as long as
> the doc is changed in some way, the document will be resurrected with
> a rev whose sequence is 1 more than that sent in the update.
> 
> Create new doc ...
> $ curl -X "PUT" -d '{"_id": "foo"}' http://localhost:15984/test/foo
> {"ok":true,"id":"foo","rev":"1-967a00dff5e02add41819138abb3284d"}
> 
> Update a couple of times to move the rev on ...
> $ curl -X "PUT" -d '{"_id": "foo", "_rev":
> "1-967a00dff5e02add41819138abb3284d"}' http://localhost:15984/test/foo
> {"ok":true,"id":"foo","rev":"2-7051cbe5c8faecd085a3fa619e6e6337"}
> $ curl -X "PUT" -d '{"_id": "foo", "_rev":
> "2-7051cbe5c8faecd085a3fa619e6e6337"}' http://localhost:15984/test/foo
> {"ok":true,"id":"foo","rev":"3-825cb35de44c433bfb2df415563a19de"}
> 
> Delete the doc ...
> $ curl -X "DELETE"
> "http://localhost:15984/test/foo?rev=3-825cb35de44c433bfb2df415563a19de"{"ok":true,"id":"foo","rev":"4-1df13287548620bf858cf9d1b810972a"}
> 
> Update using an old rev, changing something ...
> $ curl -X "PUT" -d '{"_id": "foo", "_rev":
> "1-967a00dff5e02add41819138abb3284d", "num": 1}'
> http://localhost:15984/test/foo
> {"ok":true,"id":"foo","rev":"2-65371ad05fc99a9b794f68c6003bc8da"}
> 
> Now, I can sort of understand how something like that might happen
> during replication but there's no replication going on here and
> there's no conflict created in the database.
> 
> I can't think of a way around the problem at the moment, other than
> marking the document for deletion and then sweeping it later when
> something else is hopefully not going to be touching the document.
> But, frankly, that's horrible,
> 
> - Matt


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