Fix ExtractFilterExprVisitor.

[xtcyclist]

What type of PR is this?

• bug
• feature
• enhancement

What problem(s) does this PR solve?

Issue(s) number:

Fix #5423

Description:

How do you solve it?

Special notes for your reviewer, ex. impact of this fix, design document, etc:

Checklist:

Tests:

• Unit test(positive and negative cases)
• Function test
• Performance test
• TCK

Affects:

• Documentation affected (Please add the label if documentation needs to be modified.)
• Incompatibility (If it breaks the compatibility, please describe it and add the label.）
• If it's needed to cherry-pick (If cherry-pick to some branches is required, please label the destination version(s).)
• Performance impacted: Consumes more CPU/Memory

Release notes:

Please confirm whether to be reflected in release notes and how to describe:

ex. Fixed the bug .....

[nevermore3]

a little confused, when remainedExpr_ is not equal to null

[xtcyclist]

      MATCH (v0)<-[e0]-()<-[e1]-(v1)
      WHERE (id(v0) == 6)
      AND ((NOT (NOT ((v1.Label_6.Label_6_5_Int > (e1.Rel_0_5_Int - 0.300177))
      AND v1.Label_6.Label_6_1_Bool))))
      RETURN count(*)

In this case (added in the tck), for example, the remainedExpr_ would not be equal to NULL for one time.

There are three conditions in total, forming a tree of expressions, where all index nodes are AND logics. Or, this query could be summarized to be MATCH ... WHERE <A> AND (<B> AND <C>) return ....

v1.Label_6.Label_6_5_Int > (e1.Rel_0_5_Int - 0.300177) can not be pushed down into AppendVertices. It is a leaf node in the expression tree. And, it is an remainedExpr_, while visiting its direct father node.

id(v0) == 6 also cannot be pushed down into AppendVertices. It is also an remainedExpr_.

Without this bug fix, v1.Label_6.Label_6_5_Int > (e1.Rel_0_5_Int - 0.300177) as an remainedExpr_ was thrown away, leaving only id(v0) == 6 as an remainedExpr_, because id(v0) == 6 is visited later. So, in the final query plan, there is no v1.Label_6.Label_6_5_Int > (e1.Rel_0_5_Int - 0.300177) such condition, causing wrong results.