Bug #72493 Incorrect conversion of the negative value of the TIME type (mysql) to timedelt

Description:
In my project stores many time fields in MySQL (begin and end of work times, pauses and to working time) MySQL calculates the difference (for every day, month and over the job).

I have found that many negative MySQL time values are converted incorrectly in timedelta. Go back in time values negative timedelta will also be converted incorrectly.

How to repeat:
I created a 10 test cases in 'test-timedelta.py'
Tested on Lubuntu 14.04 x86, python 3.4.0 and python 3.3.x, mysql 5.6.16-1~exp1 (Ubuntu)

The output of the tests with my comments:
vitali@vitali-VirtualBox:~$ python3 test-timedelta.py 
Readtest:
1 0:00:00.000001
2 0:00:00.000001 # wrong, should be negative
3 2 days, 0:00:00.000001
4 -2 days, 0:00:00.000001
5 0:00:01
6 0:00:01 # wrong, should be negative
7 0:01:01
8 0:01:01 # wrong, should be negative
9 1:01:01
10 -1 day, 23:01:01 # I think it is wrong, should be -1 day, 22:58:59 

Verification:
1 0:00:00.000001 0:00:00.000001 yes
2 0:00:00.000001 0:00:00.000001 no
3 2 days, 0:00:00.000001 2 days, 0:00:00.000001 yes
4 -2 days, 0:00:00.000001 -2 days, 0:00:00.000001 yes
5 0:00:01 0:00:01 yes
6 0:00:01 0:00:01 no
7 0:01:01 0:01:01 yes
8 0:01:01 0:01:01 no
9 1:01:01 1:01:01 yes
10 -1 day, 23:01:01 -1 day, 23:01:01 yes
vitali@vitali-VirtualBox:~$ 

Verification with mysql:
vitali@vitali-VirtualBox:~$ mysql -u root -p
Enter password: 
....
Server version: 5.6.16-1~exp1 (Ubuntu)
....
mysql> use test;
....
mysql> SELECT *, IF(read_ = write_,'yes','no') AS `equal?` FROM timedelta;
+----+------------------+------------------+--------+
| id | read_            | write_           | equal? |
+----+------------------+------------------+--------+
|  1 | 00:00:00.000001  | 00:00:00.000001  | yes    |
|  2 | -00:00:00.000001 | 00:00:00.000001  | no     |
|  3 | 48:00:00.000001  | 48:00:00.000001  | yes    |
|  4 | -48:00:00.000001 | -48:00:00.000001 | yes    |
|  5 | 00:00:01.000000  | 00:00:01.000000  | yes    |
|  6 | -00:00:01.000000 | 00:00:01.000000  | no     |
|  7 | 00:01:01.000000  | 00:01:01.000000  | yes    |
|  8 | -00:01:01.000000 | 00:01:01.000000  | no     |
|  9 | 01:01:01.000000  | 01:01:01.000000  | yes    |
| 10 | -01:01:01.000000 | -01:01:01.000000 | yes    |
+----+------------------+------------------+--------+
10 rows in set (0,00 sec)

mysql> 

Suggested fix:
I created the patch for mysql-connector-python-1.1.6/python3/mysql/connector/conversion.py

Test case

Attachment: test-timedelta.py (text/x-python), 1.33 KiB.

the patch for python3 and connenctor version 1.1.6

Attachment: conversion.patch (application/octet-stream, text), 1.99 KiB.

Thank you for this bug report and thank you for your patch.
We have verified and we'll make sure it's fixed.

Noted in 1.2.2 changelog.

Negative timedelta values were incorrectly converted to and from
Python.

Posted by developer:
 
Pushed to v1.2.3.

Noted in 1.2.3 changelog.

Negative timedelta values were incorrectly converted to and from
Python. Thanks to Vitali Graf for the patch.