Bug report #4946: Invalid loading of WMS layer in not recognized projection - QGIS Application - QGIS Issue Tracking

Bug report #4946

Invalid loading of WMS layer in not recognized projection

Added by Ivan Mincik almost 13 years ago. Updated over 5 years ago.

Status:	Closed
Priority:	Normal
Assignee:	-
Category:	Web Services clients/WMS
Affected QGIS version:	master	Regression?:	No
Operating System:		Easy fix?:	No
Pull Request or Patch supplied:	No	Resolution:	end of life
Crashes QGIS or corrupts data:	No	Copied to github as #:	14743

Description

QGIS is not able to correctly load WMS layer in projection, which does not exists in projection database.

It seems, that it will take layer's extent from WMS GetCapabilities request, which is in WGS84 projection a it will limit loading the layer to these values without reprojection. This can not work, because it is using extent in WGS84 (without reprojection) with layer with totally different coordinate values. 'Zoom to extent' is also not working correctly.

Ivan

History

#1 Updated by Jürgen Fischer almost 13 years ago

Assignee deleted (~~Jürgen Fischer~~)

#2 Updated by Paolo Cavallini over 12 years ago

Target version changed from Version 1.7.4 to Version 1.8.0

#3 Updated by Paolo Cavallini about 12 years ago

Target version changed from Version 1.8.0 to Version 2.0.0

#4 Updated by Giovanni Manghi about 12 years ago

Status changed from Open to Feedback

Can you post a sample layer in a public server?

#5 Updated by Ivan Mincik about 12 years ago

Giovanni Manghi wrote:

Can you post a sample layer in a public server?

Hi Giovanni,
You can replicate this behavior with any WMS server by deleting some projection from QGIS database (resources/srs.db) and trying to load layer in that projection.

#6 Updated by Jürgen Fischer over 10 years ago

Target version changed from Version 2.0.0 to Future Release - Lower Priority

#7 Updated by Giovanni Manghi about 10 years ago

You can replicate this behavior with any WMS server by deleting some projection from QGIS database (resources/srs.db) and trying to load layer in that projection.

so, if I delete a CRS from a srs.db and then connect to a WMS server that serves layers (also) in that CRS, what I see now is that in QGIS WMS client I cannot choose/change the CRS to the one was deleted, because it is not listed. That's seems to make obviously sense.

If the deleted CRS is not the default CRS proposed by the server then the user cannot get an inconsistent state, because a default CRS for the layer exists and another one can be eventually selected (one proposed by the server, eventually minus the locally deleted one).

If the deleted CRS is the default CRS proposed by the server, then the user can get an "inconsistent" state: when selecting a layer the WMS client has no default CRS for it but still the user can click on "add". At this point QGIS tries to add the layer, but has no explicit CRS asks to choose the CRS. The right one (the deleted one) cannot be choose, so any CRS the user can choose will eventually lead to reprojection problems.

The right thing to do seems to block the "add" button when there is no default candidate for the layer CRS.

Thoughts?