Feature request #2546

Singleparts to multipart makes non valid geometries

Added by dr - over 7 years ago. Updated 7 months ago.

Assignee:cfarmer -
Pull Request or Patch supplied:No Resolution:
Easy fix?:No


There is layer with valid geometries. When I try to convert single features of this layer to multifeatures with "Singleparts to multipart" tool of fTools, I get non valid multipolygon. Is it possible to get non valid multipolygon from valid polygons? In such case I guess that QGIS should inform the users about this.

valid-layer.7z (1.88 KB) dr -, 03/11/2010 10:55 PM

nonvalid2.7z (1.81 KB) dr -, 03/11/2010 10:56 PM


#1 Updated by cfarmer - about 7 years ago

This has been (partially) addressed in 8710328b (SVN r14745). I am unsure whether valid single part polygons should be able to be joined to create an invalid multi part polygon. I have been unable to determine from an extensive web search, whether this should be allowed or not? Any thoughts? In any case, a warning is now issued if the output layer contains invalid multi part geometries.


#2 Updated by Giovanni Manghi almost 6 years ago

  • Target version changed from Version 1.7.0 to Version 1.7.4

#3 Updated by Giovanni Manghi over 5 years ago

  • Target version changed from Version 1.7.4 to Version 2.0.0

#4 Updated by Pirmin Kalberer about 5 years ago

  • Target version changed from Version 2.0.0 to Future Release - Nice to have

#5 Updated by Giovanni Manghi 11 months ago

  • Category changed from 44 to Processing/QGIS

#6 Updated by Giovanni Manghi 7 months ago

  • Easy fix? set to No
  • Pull Request or Patch supplied set to No

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