fix bug: when search is the parameter of other commands

[keroro824]

eg: |history | head 2000 | search event_count>0 OR result_count>0 | dedup search | table search

[keroro824]

@salspaugh is this one worth fixing?

[salspaugh]

Hm, well I think it wouldn't be hard to fix. But let's prioritize based on how many errors a given bug causes.