Bug report #21489
Delayed prompting for CRS datum transformation
|Affected QGIS version:||3.6.0||Regression?:||Yes|
|Operating System:||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||29306|
When the QGIS CRS setting 'ask for datum transformation if several are available' is enabled, the prompt does not appear when adding data requiring a datum transformation to match the project CRS, with the default transform seemingly being used. When the layer properties of the newly added layer are opened, the prompt appears, and if a non-default transform is selected, only then is it applied to the data. This is in contrast to 2.18.28 where the prompt appears immediately on adding the dataset to the map.
This may be related to issue #21275
Steps to reproduce:
- Enable 'ask for datum transformation if several are available' prompt in QGIS settings (CRS tab)
- Load BNGdata polygon layer into a blank project, and set the project CRS to EPSG:27700
- Load WGS84data points into the project - no transformation prompt appears, points align with polygon vertices
- Open the WGS84 layer's properties. The transformation prompt appears before the properties dialog opens.
- Choose datum transformation 4, EPSG:1195, apply and observe that the points are now displaced from the polygon vertices.