This attempts to close#3973.
Handles cases where the length of the input vector to an aggregate topk
/ bottomk function is less than the K paramater. The change updates
Prometheus to allocate a result vector the same length as the input
vector in these cases.
Previously Prometheus would out-of-memory panic for large K values. This
change makes that unlikely unless the size of the input vector is
equally large.
Signed-off-by: David King <dave@davbo.org>
6286c10df0