*: fix microseconds behaviour in DATE_ADD()

[wshwsh12]

What problem does this PR solve?

#11257
Before the pr:

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 SECOND_MICROSECOND);
+----------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 SECOND_MICROSECOND) |
+----------------------------------------------------------------+
| 2007-03-28 22:08:27.980000                                     |
+----------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 MINUTE_MICROSECOND);
+----------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 MINUTE_MICROSECOND) |
+----------------------------------------------------------------+
| 2007-03-28 22:08:27.980000                                     |
+----------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 HOUR_MICROSECOND);
+--------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 HOUR_MICROSECOND) |
+--------------------------------------------------------------+
| 2007-03-28 22:08:27.980000                                   |
+--------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 DAY_MICROSECOND);
+-------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 DAY_MICROSECOND) |
+-------------------------------------------------------------+
| 2007-03-28 22:08:27.980000                                  |
+-------------------------------------------------------------+
1 row in set (0.00 sec)

This pr:

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 SECOND_MICROSECOND);
+----------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 SECOND_MICROSECOND) |
+----------------------------------------------------------------+
| 2007-03-28 22:08:27.800000                                     |
+----------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 MINUTE_MICROSECOND);
+----------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 MINUTE_MICROSECOND) |
+----------------------------------------------------------------+
| 2007-03-28 22:08:27.800000                                     |
+----------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 HOUR_MICROSECOND);
+--------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 HOUR_MICROSECOND) |
+--------------------------------------------------------------+
| 2007-03-28 22:08:27.800000                                   |
+--------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> select DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 DAY_MICROSECOND);
+-------------------------------------------------------------+
| DATE_ADD('2007-03-28 22:08:28',INTERVAL -2 DAY_MICROSECOND) |
+-------------------------------------------------------------+
| 2007-03-28 22:08:27.800000                                  |
+-------------------------------------------------------------+
1 row in set (0.00 sec)

What is changed and how it works?

When using parseTimeValue function to get microseconds from string, It will use func alignFrac to generate alignment frac.
Before this pr, the func hasn't consider the possible that the beginning of the string is a '-'.
e.g. 123 -> 123000 ,-123 -> -12300 (the '-' occupy a space)

This pr, fix the logic of the function. If the string is started with a '-', do a special treatment.
-123 -> -123000

Check List

Tests

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

Code changes

• Has exported function/method change

Side effects

• Increased code complexity

Related changes

• Need to cherry-pick to the release branch

[wshwsh12]

/run-all-tests

[codecov]

Codecov Report

Merging #11280 into master will increase coverage by 0.1459%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##             master     #11280       +/-   ##
===============================================
+ Coverage   81.3302%   81.4762%   +0.146%     
===============================================
  Files           423        423               
  Lines         90344      90689      +345     
===============================================
+ Hits          73477      73890      +413     
+ Misses        11554      11499       -55     
+ Partials       5313       5300       -13

[SunRunAway]

LGTM

[XuHuaiyu]

LGTM