Fix bugs in service/datastore

Fix bugs in service/datastore

R=dnj@chromium.org, estaab@chromium.org, maruel@chromium.org, tandrii@chromium.org, vadimsh@chromium.org
BUG=

Committed: https://github.com/luci/gae/commit/76382c09c971ad57d3b9c0cb53d3c18c816a65bb

[dnj, 2015-09-29 19:06:23]

lgtm w/ nits

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query.go
File service/datastore/query.go (right):

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query.go#...
service/datastore/query.go:485: allowedEqs := 0
nit: IMO just split this out into a "with ancestor" and "without ancestor" case,
each of which has its own more descriptive error message.

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query_tes...
File service/datastore/query_test.go (right):

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query_tes...
service/datastore/query_test.go:288: {"ineq on __key__ with ancestor must be in
range",
nit: is "in range" accurate here? The condition you're testing is an ancestor
difference. (Same for next test).

[iannucci, 2015-09-29 19:19:55]

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query.go
File service/datastore/query.go (right):

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query.go#...
service/datastore/query.go:485: allowedEqs := 0
On 2015/09/29 at 19:06:23, dnj wrote:
> nit: IMO just split this out into a "with ancestor" and "without ancestor"
case, each of which has its own more descriptive error message.

but there's only one case. We're computing the threshold for comparison here.

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query_tes...
File service/datastore/query_test.go (right):

https://codereview.chromium.org/1378613003/diff/1/service/datastore/query_tes...
service/datastore/query_test.go:288: {"ineq on __key__ with ancestor must be in
range",
On 2015/09/29 at 19:06:23, dnj wrote:
> nit: is "in range" accurate here? The condition you're testing is an ancestor
difference. (Same for next test).

updated

[iannucci, 2015-09-29 19:20:21]

The CQ bit was checked by iannucci@chromium.org

[iannucci, 2015-09-29 19:20:21]

The patchset sent to the CQ was uploaded after l-g-t-m from dnj@chromium.org
Link to the patchset: https://codereview.chromium.org/1378613003/#ps20001
(title: "fixit")

[commit-bot: I haz the power, 2015-09-29 19:20:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1378613003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1378613003/20001

[commit-bot: I haz the power, 2015-09-29 19:21:59]

Committed patchset #2 (id:20001) as
https://github.com/luci/gae/commit/76382c09c971ad57d3b9c0cb53d3c18c816a65bb