fixes #18497 : Correct line size method when snapping multipolygon

troopa81 · nyalldawson · commit abda6c42ff99 · 2019-01-24T20:55:13.000+11:00
diff --git a/src/analysis/vector/qgsgeometrysnapper.cpp b/src/analysis/vector/qgsgeometrysnapper.cpp
@@ -23,6 +23,7 @@
 #include "qgsgeometryutils.h"
 #include "qgsmapsettings.h"
 #include "qgssurface.h"
+#include "qgsmultisurface.h"
 #include "qgscurve.h"
 
 ///@cond PRIVATE
@@ -718,7 +719,7 @@ int QgsGeometrySnapper::polyLineSize( const QgsAbstractGeometry *geom, int iPart
 {
   int nVerts = geom->vertexCount( iPart, iRing );
 
-  if ( qgsgeometry_cast< const QgsSurface * >( geom ) )
+  if ( qgsgeometry_cast< const QgsSurface * >( geom ) || qgsgeometry_cast< const QgsMultiSurface * >( geom ) )
   {
     QgsPoint front = geom->vertexAt( QgsVertexId( iPart, iRing, 0 ) );
     QgsPoint back = geom->vertexAt( QgsVertexId( iPart, iRing, nVerts - 1 ) );
diff --git a/tests/src/analysis/testqgsgeometrysnapper.cpp b/tests/src/analysis/testqgsgeometrysnapper.cpp
@@ -50,6 +50,7 @@ class TestQgsGeometrySnapper : public QObject
     void internalSnapper();
     void insertExtra();
     void duplicateNodes();
+    void snapMultiPolygonToPolygon();
 };
 
 void  TestQgsGeometrySnapper::initTestCase()
@@ -612,6 +613,24 @@ void TestQgsGeometrySnapper::duplicateNodes()
 
 }
 
+void TestQgsGeometrySnapper::snapMultiPolygonToPolygon()
+{
+  QgsVectorLayer *rl = new QgsVectorLayer( QStringLiteral( "Polygon" ), QStringLiteral( "x" ), QStringLiteral( "memory" ) );
+  QgsFeature ff( 0 );
+  QgsGeometry refGeom = QgsGeometry::fromWkt( QStringLiteral( "Polygon((0 0, 10 0, 10 10, 0 10, 0 0))" ) );
+  ff.setGeometry( refGeom );
+  QgsFeatureList flist;
+  flist << ff;
+  rl->dataProvider()->addFeatures( flist );
+
+  // test MultiPolygon that could be removed in the process https://issues.qgis.org/issues/18497
+  QgsGeometry polygonGeom = QgsGeometry::fromWkt( QStringLiteral( "MultiPolygon(((0.1 -0.1, 5 0.1, 9.9 0.1, 0.1 -0.1)))" ) );
+  QgsGeometrySnapper snapper( rl );
+  QgsGeometry result = snapper.snapGeometry( polygonGeom, 1 );
+  QCOMPARE( result.asWkt(), QStringLiteral( "MultiPolygon (((0 0, 5 0, 10 0, 0 0)))" ) );
+
+}
+
 
 QGSTEST_MAIN( TestQgsGeometrySnapper )
 #include "testqgsgeometrysnapper.moc"

Original file line number	Diff line number	Diff line change
`@@ -23,6 +23,7 @@`
`23`	`23`	`#include "qgsgeometryutils.h"`
`24`	`24`	`#include "qgsmapsettings.h"`
`25`	`25`	`#include "qgssurface.h"`
	`26`	`+#include "qgsmultisurface.h"`
`26`	`27`	`#include "qgscurve.h"`
`27`	`28`
`28`	`29`	`///@cond PRIVATE`
`@@ -718,7 +719,7 @@ int QgsGeometrySnapper::polyLineSize( const QgsAbstractGeometry *geom, int iPart`
`718`	`719`	`{`
`719`	`720`	`int nVerts = geom->vertexCount( iPart, iRing );`
`720`	`721`
`721`		`- if ( qgsgeometry_cast< const QgsSurface * >( geom ) )`
	`722`	`+ if ( qgsgeometry_cast< const QgsSurface * >( geom ) \|\| qgsgeometry_cast< const QgsMultiSurface * >( geom ) )`
`722`	`723`	`{`
`723`	`724`	`QgsPoint front = geom->vertexAt( QgsVertexId( iPart, iRing, 0 ) );`
`724`	`725`	`QgsPoint back = geom->vertexAt( QgsVertexId( iPart, iRing, nVerts - 1 ) );`