Bug #117048 ST_Buffer gives unexpected reuslt using end_flat strategy with closed Linestring
Submitted: 26 Dec 2024 9:06 Modified: 30 Dec 2024 13:44
Reporter: shijie li Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: GIS Severity:S2 (Serious)
Version:8.0.40 OS:Any
Assigned to: CPU Architecture:Any

[26 Dec 2024 9:06] shijie li
Description:
A closed Linestring is actually a LinearRing, when we ask for a buffer using end_flat strategy with  on a LineaRing, ST_Buffer() still flattens the declared ending point, which is also the starting point.

How to repeat:
SELECT ST_AsText(ST_Buffer(ST_GeomFromText('LINESTRING (-20 0, 0 20, 20 0, 0 -20, -20 0)'), 50, ST_Buffer_Strategy("end_flat")));
[26 Dec 2024 11:43] MySQL Verification Team
Hello shijie li,

Thank you for the report and feedback.

regards,
Umesh
[30 Dec 2024 13:44] shijie li
If possible, please let me know the reason for the bug and whether you will fix this bug. Thank you.