Bug report #12209

Problem Snapping to segments in PostGIS

Added by Francisco Javier Garcia about 9 years ago. Updated almost 5 years ago.

Affected QGIS version:2.6.0 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 #:20398


Working with snapping in 2.6.1. release, we have found a problem with a Postgres/PostGIS layer, when we try to snap a node from a layer to a vertex of another line of the same layer orto another line of other postgres layer.

We hoped that by moving the vertex to the other line, a new vertex was going to be created in the line to separate the segment at the new position (this works correctly in a shapefile) but it seems that the vertex snaps to the line but a new vertex is not created.
We have tested with other lines of other features (layers) and the result is the same. We have tested in a shapefile and in this case it doesn't work either.

The steps to reproduce are the following
1. Load a line layer from a PostGIS database
2. Activate the snap to vertex and segment for this layer. Change the tolerance.
3. Enable the editing in the layer
4. Create one line
5. Create another line and try to snap the vertex of the last line to the middle of the first line
6. Apparently the vertex changes its color to snap to the vertex but we finish the transaction, a new vertex is not created in the middle of the line.

If we reproduce these steps with a shapefile, instead of a postgis layers it works perfectly, a new vertex is created.

We have tried also with features of different postgis layers and the result is the same. The vertex in the middle is not created.

Thanks in advance.


#1 Updated by Jürgen Fischer about 9 years ago

Does this also apply to master?

#2 Updated by Francisco Javier Garcia about 9 years ago

I have tested with the master version and the error is the same.

#3 Updated by Giovanni Manghi almost 7 years ago

  • Easy fix? set to No
  • Regression? set to No

#4 Updated by Loïc BARTOLETTI over 5 years ago

Does this also apply to QGIS 3?

If yes, can you post a dataset and a video of this bug?

#5 Updated by Giovanni Manghi almost 5 years ago

  • Status changed from Open to Closed
  • Resolution set to end of life

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