tree c081dd0cb38f4271c95baeb9b478ac72ea9a92f2
parent 3b62515ce179a17ad70af9f6aee9ec24f8194498
author Dave Borowitz <dborowitz@google.com> 1551832440 -0800
committer Luca Milanesio <luca.milanesio@gmail.com> 1668804051 +0000

Predicate: Add safety check against not(any())

It's tempting to use as a way to say "match no results", but it's very
unsafe. This simple check won't catch all misuses, but it would have
prevented Iad564dd47 from causing production problems.

Fix one obvious caller that now trips this check. This was a real
problem: a bare [is:watched] query on a large site for a user with no
project watches required iterating all changes to return an empty
result. We have real instances of this causing extremely long requests
in our server logs.

Release-Notes: skip
Change-Id: Ib43f7466db5db315bf87558a37f18a1832ec641f
(cherry picked from commit 02bab2161cd7ce7f682a28dad496a4465cb40844)