TermStringList returns wrong index for empty string

Description

TermStringList return wrong index for empty string.
If search empty string in TermStringList, it could return dummy header if it has a dummy header.

This will result wrong search result.
If you select empty string for one facet, it could return some docs which don't have this term at all.

Environment

None

Status

Assignee

John Wang

Reporter

Yonghui Zhao

Labels

None

Priority

Major