Inconsistent handling of 3D and 4D postgis data

[qgib]

Author Name: Sandro Santilli (@strk)
Original Redmine Issue: 12310
Affected QGIS version: 2.8.1
Redmine category:data_provider/postgis

---

4D geometries are "flattened" down to 2D (using Force2D) while 3D geometries (both 3DZ and 3DM) are kept that way.
This is inconsistent. Either we should allow 3d, thus forcing 4D to 3d (3dz or 3dm) or we should never flat and keep
all the dimensions. If we flat to 3d we should choose whether we keep Z or M and if we keep Z I guess we can then
flatten down 3dM to 2D as well...

\cc @mhugo @jef

See also #11533

---

Related issue(s): #11533 (relates), #17687 (relates)
Redmine related issue(s): 1473, 9032

---

[qgib]

Author Name: Jürgen Fischer (@jef-n)

---

See also "QEP#8":https://github.com/mhugent/QGIS-Enhancement-Proposals/blob/master/QEP-8-geometry_redesign.rst

[qgib]

Author Name: Jürgen Fischer (@jef-n)

---

• category_id was configured as Data Provider/PostGIS

[qgib]

Author Name: Giovanni Manghi (@gioman)

---

• easy_fix was configured as 0
• regression was configured as 0

[qgib]

Author Name: Giovanni Manghi (@gioman)

---

End of life notice: QGIS 2.18 LTR

Source:
http://blog.qgis.org/2019/03/09/end-of-life-notice-qgis-2-18-ltr/

---

• resolution was changed from to end of life
• status_id was changed from Open to Closed