Bug report #18541
Fixed Distance Buffer makes 0 (zero) distance invalid
| Status: | Closed | ||
|---|---|---|---|
| Priority: | High | ||
| Assignee: |  Victor Olaya | ||
| Category: | Processing/QGIS | ||
| Affected QGIS version: | 2.18.17 | Regression?: | Yes |
| Operating System: | W10 | Easy fix?: | No |
| Pull Request or Patch supplied: | No | Resolution: | up/downstream |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 26429 |
Description
I do a fixed-distance buffer on a polygon layer with the distance parameter as 0.0 (zero). This fails because 0 (zero) is classed as an invalid distance.
In older QGIS versions, and in the OGR 'Buffer Vectors' algorithm, this works well, and I have often used it as a method to remove most types of invalid geometry. Therefore, I think this is a regression.
zero_distance_fixed_buffer_log.txt 
(2.15 KB)
History
#1
Updated by Nyall Dawson over 6 years ago
- Resolution set to up/downstream
- Status changed from Open to Closed
This is not a qgis bug, it's a bug in SAGA.
You could try the other buffer algorithms such as the native QGIS "fixed distance buffer" algorithm instead.
#2
Updated by Steve Lowman over 6 years ago
Thank you, yes, I was testing the tool in the wrong list. I was trying to test whether the native tool can work on features with invalid geometry. It cannot (see #17291), so I think it is best to use the OGR buffer tool for fixed distance, and perhaps the Saga one for variable distance buffers.
I wonder whether I should make a feature request to replace the native buffer tools in the Vector menu for QGIS 2, due to the outcome of #17291?