reftable: enforce ascending order in sortAndWriteRefs

MergedReftableTest#scanDuplicates tests whether we can write duplicate
keys in a merged reftable. Apparently, the first key appearing should
get precedence, and this works because the sort() algorithm on ordered
collections is stable.

This is potentially confusing behavior, because you can write data
into the table that cannot be retrieved (Merged table can only have
one entry per key), and the APIs such as exactRef() only return a
single value.

Make this consistent with behavior introduced in I04f55c481 "reftable:
enforce ordering for ref and log writes" by considering a duplicate key
in sortAndWriteRefs as a fatal runtime error.

Change-Id: I1eedd18f028180069f78c5c467169dcfe1521157
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>

0 files changed, 0 insertions, 0 deletions