Fill doesn't work correctly when no lower time bound specified

[dgnorton]

Given a database with the following two values:

> select watts from pwr where time <= 3600000000000
name: pwr
time                 watts
----                 -----
1970-01-01T00:00:00Z 100
1970-01-01T01:00:00Z 500

The following query:

SELECT mean(watts) FROM pwr WHERE time <= 3600000000000 GROUP BY time(1h) LIMIT 5

Returns:

name: pwr
time                 mean
----                 ----
1970-01-01T00:00:00Z 100
1677-09-21T01:00:00Z 
1677-09-21T02:00:00Z 
1677-09-21T03:00:00Z 
1677-09-21T04:00:00Z

Note that the filled dates are out of order.

Adding a lower time bound:

SELECT mean(watts) FROM pwr WHERE time >= -7200000000000 AND time <= 3600000000000 GROUP BY time(1h) LIMIT 5

Gives the expected results:

name: pwr
time                 mean
----                 ----
1969-12-31T22:00:00Z 
1969-12-31T23:00:00Z 
1970-01-01T00:00:00Z 100
1970-01-01T01:00:00Z 500

This zip file contains a repro script.

[jsternberg]

It looks like window computation when the time is very high or very low causes an overflow.