Panic when querying for non existing value with pilosa index

[kuba--]

CREATE INDEX email_idx ON commits USING pilosa (commit_author_email);
SELECT count(*) FROM commits WHERE  commit_author_email='existing email' OR commit_author_email='trash';

Got:

...
lookup.go:87 (0x4927553)
(*indexLookup).bitmapQuery: if b.Error() != nil {

Fix:

b, err := il.bitmapQuery()
if err != nil {
return nil, err
}
 if b == nil {
continue
}

[kuba--]

it works for pilosalib driver