Ensure that stoptime and starttime are set for finished builds

src/sql/upgrade-15.sql

@@ -0,0 +1,10 @@
+-- Previously we didn't always set stoptime.  For those builds, set
+-- stoptime to timestamp, since back then timestamp was the time the
+-- build finished (for finished builds).
+update builds set stoptime = timestamp where finished = 1 and (stoptime is null or stoptime = 0);
+
+-- Idem for starttime.
+update builds set starttime = timestamp where finished = 1 and (starttime is null or starttime = 0);
+
+alter table builds add check (finished = 0 or (stoptime is not null and stoptime != 0));
+alter table builds add check (finished = 0 or (starttime is not null and starttime != 0));