feat(avoidIntersections): add a new return value when the geom is not modified

Koyaani · Koyaani · commit 864ed43b7ce9 · 2022-11-29T17:48:32.000+01:00
diff --git a/python/core/auto_generated/geometry/qgsgeometry.sip.in b/python/core/auto_generated/geometry/qgsgeometry.sip.in
@@ -2343,6 +2343,7 @@ Modifies geometry to avoid intersections with the layers specified in project pr
          1 if geometry is not of polygon type,
          2 if avoid intersection would change the geometry type,
          3 at least one geometry intersected is invalid. The algorithm may not work and return the same geometry as the input. You must fix your intersecting geometries.
+         4 if the geometry is not intersected by one of the geometries present in the provided layers.
 
 .. versionadded:: 1.5
 %End
diff --git a/src/core/geometry/qgsgeometry.cpp b/src/core/geometry/qgsgeometry.cpp
@@ -2850,15 +2850,20 @@ int QgsGeometry::avoidIntersections( const QList<QgsVectorLayer *> &avoidInterse
   QgsWkbTypes::Type geomTypeBeforeModification = wkbType();
 
   bool haveInvalidGeometry = false;
+  bool geomModified = false;
+
   std::unique_ptr< QgsAbstractGeometry > diffGeom = QgsGeometryEditUtils::avoidIntersections( *( d->geometry ), avoidIntersectionsLayers, haveInvalidGeometry, ignoreFeatures );
   if ( diffGeom )
   {
     reset( std::move( diffGeom ) );
+    geomModified = true;
   }
 
   if ( geomTypeBeforeModification != wkbType() )
     return 2;
   if ( haveInvalidGeometry )
+    return 3;
+  if ( !geomModified )
     return 4;
 
   return 0;
diff --git a/src/core/geometry/qgsgeometry.h b/src/core/geometry/qgsgeometry.h
@@ -2406,6 +2406,7 @@ class CORE_EXPORT QgsGeometry
      *          1 if geometry is not of polygon type,
      *          2 if avoid intersection would change the geometry type,
      *          3 at least one geometry intersected is invalid. The algorithm may not work and return the same geometry as the input. You must fix your intersecting geometries.
+     *          4 if the geometry is not intersected by one of the geometries present in the provided layers.
      * \since QGIS 1.5
      */
     int avoidIntersections( const QList<QgsVectorLayer *> &avoidIntersectionsLayers,
diff --git a/src/core/geometry/qgsgeometryeditutils.cpp b/src/core/geometry/qgsgeometryeditutils.cpp
@@ -343,6 +343,10 @@ std::unique_ptr<QgsAbstractGeometry> QgsGeometryEditUtils::avoidIntersections( c
   }
 
   std::unique_ptr< QgsAbstractGeometry > diffGeom( geomEngine->difference( combinedGeometries.get() ) );
+  if ( geomEngine->isEqual( diffGeom.get() ) )
+  {
+    return nullptr;
+  }
 
   return diffGeom;
 }

Original file line number	Diff line number	Diff line change
`@@ -343,6 +343,10 @@ std::unique_ptr<QgsAbstractGeometry> QgsGeometryEditUtils::avoidIntersections( c`
`343`	`343`	`}`
`344`	`344`
`345`	`345`	`std::unique_ptr< QgsAbstractGeometry > diffGeom( geomEngine->difference( combinedGeometries.get() ) );`
	`346`	`+ if ( geomEngine->isEqual( diffGeom.get() ) )`
	`347`	`+ {`
	`348`	`+ return nullptr;`
	`349`	`+ }`
`346`	`350`
`347`	`351`	`return diffGeom;`
`348`	`352`	`}`