planner: fix wrong empty projection | tidb-test=pr/2327

[winoros]

What problem does this PR solve?

Issue Number: close #49109

Problem Summary:

Projection is wrongly pruned to a empty one after the second round of column pruning

What changed and how does it work?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.4544%. Comparing base (4fe70da) to head (746448e).
Report is 2 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #53235        +/-   ##
================================================
+ Coverage   72.4796%   74.4544%   +1.9747%     
================================================
  Files          1493       1493                
  Lines        429362     429401        +39     
================================================
+ Hits         311200     319708      +8508     
+ Misses        98931      89815      -9116     
- Partials      19231      19878       +647     

Flag	Coverage Δ
integration	48.5721% <100.0000%> (?)
unit	71.6859% <100.0000%> (+0.3071%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9957% <ø> (ø)
parser	∅ <ø> (∅)
br	50.1505% <ø> (+8.7103%)	⬆️

[winoros]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AilinKid, guo-shaoge

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Needs approval from an approver in each of these files:

• OWNERS [AilinKid,guo-shaoge]
• pkg/planner/OWNERS [AilinKid]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-13 13:20:50.311692546 +0000 UTC m=+1486604.068828118: ☑️ agreed by guo-shaoge.
• 2024-05-13 16:13:38.60301042 +0000 UTC m=+1496972.360145994: ☑️ agreed by AilinKid.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #53238.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #53239.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #53240.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #53241.