Go's CL numbers as assigned by Gerrit have started to collide with the
lower numbers in the sparse set of CL numbers as returned by our old
code review system (Rietveld).
The old heuristic no longer works now that Gerrit CL numbers have
reached 150000.
Instead, include a map of the low Rietveld CL numbers where we might
overlap and bump the threshold heuristic up.
Updates golang/go#28836
Change-Id: Ice719ab807ce3922b885a800ac873cdbf165a8f7
Reviewed-on: https://go-review.googlesource.com/c/150057
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
