Bug report #13601

error calculating area for polygons when otf reprojection is on and the CRS is Indian 1960 48N

Added by Mathieu Pellerin - nIRV about 9 years ago. Updated about 9 years ago.

Status:Closed
Priority:Severe/Regression
Assignee:Nyall Dawson
Category:Projection Support
Affected QGIS version:master Regression?:No
Operating System: Easy fix?:No
Pull Request or Patch supplied:No Resolution:
Crashes QGIS or corrupts data:No Copied to github as #:21643

Description

I have just been able to reproduce the circumstances of a serious issue leading to area calculation not working when on-the-fly (OTF) reprojection is switched on. The gist of it is that when OTF reprojection is on, layers with CRS being Indian 1960 48N (and most probably other CRSes), area calculation (in the identity panel) is broken and returns wrong values. Similarly, if polygon features are labeled as $area, nothing is returned.

Steps to reproduce:
  1. Launch QGIS
  2. Add the concessions.zip layer to the project (CRS: Indian 1960 48N)
  3. At this stage, OTF is off; check the area of a polygon via the identify tool to verify it works
  4. Turn OTF on
  5. Check the area of the same polygon via the identify tool to confirm the value is broken (values such as 0.0000, or 0.0008 m2, etc.)

cambodia.zip (356 KB) Mathieu Pellerin - nIRV, 2015-10-14 07:50 PM

concessions.zip (300 KB) Mathieu Pellerin - nIRV, 2015-10-14 07:59 PM

Associated revisions

Revision 5654eeca
Added by Nyall Dawson about 9 years ago

Fix area calculation when OTF active and no ellipsoid (fix #13601)

History

#1 Updated by Mathieu Pellerin - nIRV about 9 years ago

  • File deleted (licadho-land-concessions-2015.zip)

#3 Updated by Mathieu Pellerin - nIRV about 9 years ago

  • Subject changed from error calculating area for polygons when otf reprojection automatically switched on via new layer crs != project crs to error calculating area for polygons when otf reprojection is on and the CRS is Indian 1960 48N
  • Priority changed from High to Severe/Regression
  • Target version changed from Future Release - High Priority to Version 2.12

#4 Updated by Nyall Dawson about 9 years ago

  • Assignee set to Nyall Dawson

Ouch. Got it - thanks for reporting!

#5 Updated by Nyall Dawson about 9 years ago

  • Status changed from Open to Closed

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