Fixed #33783 -- Added IsEmpty GIS database function and __isempty lookup on PostGIS.

4 files changed, 38 insertions, 5 deletions

diff --git a/docs/ref/contrib/gis/db-api.txt b/docs/ref/contrib/gis/db-api.txt
index bc216c7caf..97f1f6ca6b 100644
--- a/docs/ref/contrib/gis/db-api.txt
+++ b/docs/ref/contrib/gis/db-api.txt
@@ -316,6 +316,7 @@ Lookup Type                        PostGIS    Oracle   MariaDB   MySQL [#]_   Sp
 :lookup:`equals`                   X          X        X         X            X          C
 :lookup:`exact <same_as>`          X          X        X         X            X          B
 :lookup:`intersects`               X          X        X         X            X          B
+:lookup:`isempty`                  X
 :lookup:`isvalid`                  X          X                  X            X
 :lookup:`overlaps`                 X          X        X         X            X          B
 :lookup:`relate`                   X          X        X                      X          C
@@ -361,6 +362,7 @@ Function                              PostGIS  Oracle         MariaDB      MySQL
 :class:`ForcePolygonCW`               X                                                X
 :class:`GeoHash`                      X                                    X           X (LWGEOM/RTTOPO)
 :class:`Intersection`                 X        X              X            X           X
+:class:`IsEmpty`                      X
 :class:`IsValid`                      X        X                           X           X
 :class:`Length`                       X        X              X            X           X
 :class:`LineLocatePoint`              X                                                X
diff --git a/docs/ref/contrib/gis/functions.txt b/docs/ref/contrib/gis/functions.txt
index 00c48e665e..1c062515c6 100644
--- a/docs/ref/contrib/gis/functions.txt
+++ b/docs/ref/contrib/gis/functions.txt
@@ -23,11 +23,11 @@ Function's summary:
 =========================  ========================  ======================  =======================  ==================  =====================
 Measurement                Relationships             Operations              Editors                  Output format       Miscellaneous
 =========================  ========================  ======================  =======================  ==================  =====================
-:class:`Area`              :class:`Azimuth`          :class:`Difference`     :class:`ForcePolygonCW`  :class:`AsGeoJSON`  :class:`IsValid`
-:class:`Distance`          :class:`BoundingCircle`   :class:`Intersection`   :class:`MakeValid`       :class:`AsGML`      :class:`MemSize`
-:class:`GeometryDistance`  :class:`Centroid`         :class:`SymDifference`  :class:`Reverse`         :class:`AsKML`      :class:`NumGeometries`
-:class:`Length`            :class:`Envelope`         :class:`Union`          :class:`Scale`           :class:`AsSVG`      :class:`NumPoints`
-:class:`Perimeter`         :class:`LineLocatePoint`                          :class:`SnapToGrid`      :class:`AsWKB`
+:class:`Area`              :class:`Azimuth`          :class:`Difference`     :class:`ForcePolygonCW`  :class:`AsGeoJSON`  :class:`IsEmpty`
+:class:`Distance`          :class:`BoundingCircle`   :class:`Intersection`   :class:`MakeValid`       :class:`AsGML`      :class:`IsValid`
+:class:`GeometryDistance`  :class:`Centroid`         :class:`SymDifference`  :class:`Reverse`         :class:`AsKML`      :class:`MemSize`
+:class:`Length`            :class:`Envelope`         :class:`Union`          :class:`Scale`           :class:`AsSVG`      :class:`NumGeometries`
+:class:`Perimeter`         :class:`LineLocatePoint`                          :class:`SnapToGrid`      :class:`AsWKB`      :class:`NumPoints`
 ..                         :class:`PointOnSurface`                           :class:`Transform`       :class:`AsWKT`
 ..                                                                           :class:`Translate`       :class:`GeoHash`
 =========================  ========================  ======================  =======================  ==================  =====================
@@ -368,6 +368,18 @@ it provides index-assisted nearest-neighbor result sets.
 Accepts two geographic fields or expressions and returns the geometric
 intersection between them.
 
+``IsEmpty``
+===========
+
+.. versionadded:: 4.2
+
+.. class:: IsEmpty(expr)
+
+*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__
+
+Accepts a geographic field or expression and tests if the value is an empty
+geometry. Returns ``True`` if its value is empty and ``False`` otherwise.
+
 ``IsValid``
 ===========
 
diff --git a/docs/ref/contrib/gis/geoquerysets.txt b/docs/ref/contrib/gis/geoquerysets.txt
index 760d508b17..53a8b6c3b9 100644
--- a/docs/ref/contrib/gis/geoquerysets.txt
+++ b/docs/ref/contrib/gis/geoquerysets.txt
@@ -346,6 +346,21 @@ MySQL       ``ST_Intersects(poly, geom)``
 SpatiaLite  ``Intersects(poly, geom)``
 ==========  =================================================
 
+.. fieldlookup:: isempty
+
+``isempty``
+-----------
+
+.. versionadded:: 4.2
+
+*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__
+
+Tests if the geometry is empty.
+
+Example::
+
+    Zipcode.objects.filter(poly__isempty=True)
+
 .. fieldlookup:: isvalid
 
 ``isvalid``
diff --git a/docs/releases/4.2.txt b/docs/releases/4.2.txt
index 6d2fb32644..40ca5ba1a7 100644
--- a/docs/releases/4.2.txt
+++ b/docs/releases/4.2.txt
@@ -155,6 +155,10 @@ Minor features
 * :class:`~django.contrib.gis.forms.widgets.OpenLayersWidget` is now based on
   OpenLayers 7.2.2 (previously 4.6.5).
 
+* The new :lookup:`isempty` lookup and
+  :class:`IsEmpty() <django.contrib.gis.db.models.functions.IsEmpty>`
+  expression allow filtering empty geometries on PostGIS.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~