FWIW, I get the same with 0.10.1 so it doesn't appear to be a regression. Both current and 0.10.1 were built under Ubuntu Hardy with spidermonkey 1.8.1.18
$ curl http://127.0.0.1:5984 {"couchdb":"Welcome","version":"0.10.1"} $ curl -X PUT http://127.0.0.1:5984/briantest {"ok":true} $ curl -d '{}' -X PUT http://127.0.0.1:5984/briantest/foo {"ok":true,"id":"foo","rev":"1-967a00dff5e02add41819138abb3284d"} $ curl -d '{"map":"function(doc) {}"}' -X POST http://127.0.0.1:5984/briantest/_temp_view {"total_rows":0,"offset":0,"rows":[]} $ curl -d '{"map":"function(doc) {emit(Date(0),null);}"}' -X POST http://127.0.0.1:5984/briantest/_temp_view {"total_rows":1,"offset":0,"rows":[ {"id":"foo","key":"Tue Feb 09 2010 11:01:31 GMT+0000 (BST)","value":null} ]} $ curl -d '{"map":"function(doc) {emit(JSON.stringify([]),null);}"}' -X POST http://127.0.0.1:5984/briantest/_temp_view {"total_rows":0,"offset":0,"rows":[]} [Tue, 09 Feb 2010 11:08:16 GMT] [info] [<0.130.0>] OS Process :: function raised exception (ReferenceError: JSON is not defined) with doc._id foo
