util: fix codec for negative zero(#57343) | tidb-test=pr/2429

[ti-chi-bot]

This is an automated cherry-pick of #57343

What problem does this PR solve?

Issue Number: close #41878
Negative zero is incorrectly converted to zero after being encoded and then decoded.

Problem Summary:
Correctly handle the encoding issue of negative zero.

What changed and how does it work?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

tidb> CREATE TABLE t1 (c0 decimal(10,0));
Query OK, 0 rows affected (0.11 sec)

tidb> INSERT INTO t1 VALUES (0);
Query OK, 1 row affected (0.02 sec)

tidb> SELECT c0 FROM t1 WHERE CAST(ATAN2(((t1.c0) IS NULL), (- (''))) AS TIME); -- actual: {}, expected: {0}
+------+
| c0   |
+------+
|    0 |
+------+
1 row in set (0.00 sec)

• 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 ✅

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Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.5     #57453   +/-   ##
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  Lines                  ?     626375           
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  Hits                   ?     356958           
  Misses                 ?     245346           
  Partials               ?      24071           

Flag	Coverage Δ
integration	37.2510% <100.0000%> (?)
unit	72.6570% <100.0000%> (?)

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

Components	Coverage Δ
dumpling	52.9478% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	52.4309% <0.0000%> (?)

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[wshwsh12]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wshwsh12, XuHuaiyu

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Needs approval from an approver in each of these files:

• OWNERS [XuHuaiyu,wshwsh12]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-11-19 03:27:56.842828654 +0000 UTC m=+931639.033697650: ☑️ agreed by XuHuaiyu.
• 2024-11-19 03:29:21.456246341 +0000 UTC m=+931723.647115338: ☑️ agreed by wshwsh12.