Fix reshape tool fails in certain circumstances when line matching

tolerance is incorrectly handled (cherry picked from commit 019b75d)
qgis · Nov 20, 2020 · e51a263 · e51a263
1 parent 98abc4f
commit e51a263
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Showing 2 changed files with 28 additions and 2 deletions.
diff --git a/src/core/geometry/qgsgeos.cpp b/src/core/geometry/qgsgeos.cpp
@@ -2563,9 +2563,24 @@ geos::unique_ptr QgsGeos::reshapeLine( const GEOSGeometry *line, const GEOSGeome
 
   for ( int i = 0; i < numMergedLines; ++i )
   {
-    const GEOSGeometry *currentGeom = nullptr;
+    const GEOSGeometry *currentGeom = GEOSGetGeometryN_r( geosinit()->ctxt, mergedLines.get(), i );
+
+    // have we already added this part?
+    bool alreadyAdded = false;
+    double distance = 0;
+    double bufferDistance = std::pow( 10.0L, geomDigits( currentGeom ) - 11 );
+    for ( const GEOSGeometry *other : qgis::as_const( resultLineParts ) )
+    {
+      GEOSHausdorffDistance_r( geosinit()->ctxt, currentGeom, other, &distance );
+      if ( distance < bufferDistance )
+      {
+        alreadyAdded = true;
+        break;
+      }
+    }
+    if ( alreadyAdded )
+      continue;
 
-    currentGeom = GEOSGetGeometryN_r( geosinit()->ctxt, mergedLines.get(), i );
     const GEOSCoordSequence *currentCoordSeq = GEOSGeom_getCoordSeq_r( geosinit()->ctxt, currentGeom );
     unsigned int currentCoordSeqSize;
     GEOSCoordSeq_getSize_r( geosinit()->ctxt, currentCoordSeq, &currentCoordSeqSize );

diff --git a/tests/src/python/test_qgsgeometry.py b/tests/src/python/test_qgsgeometry.py
@@ -2649,6 +2649,17 @@ def testReshape(self):
         wkt = g.asWkt()
         self.assertTrue(compareWkt(expWkt, wkt), "testReshape failed: mismatch Expected:\n%s\nGot:\n%s\n" % (expWkt, wkt))
 
+        # test that tolerance is correctly handled
+        g = QgsGeometry.fromWkt(
+            'LineString(152.96370660521466789 -25.60915858374441356, 152.96370887800003402 -25.60912889999996978, 152.9640088780000724 -25.60858889999996535, 152.96423077601289719 -25.60858080133134962, 152.96423675797717578 -25.60854355430449658, 152.96427575123991005 -25.60857916087011432, 152.96537884400004259 -25.60853889999992106, 152.96576355343805176 -25.60880035169972047)')
+        self.assertEqual(g.reshapeGeometry(QgsLineString([QgsPoint(152.9634281, -25.6079985),
+                                                          QgsPoint(152.9640088780000724, -25.60858889999996535),
+                                                          QgsPoint(152.96537884400004259, -25.60853889999992106),
+                                                          QgsPoint(152.9655739, -25.6083169)])), 0)
+        expWkt = 'LineString (152.96371 -25.60916, 152.96371 -25.60913, 152.96401 -25.60859, 152.96423 -25.60858, 152.96423 -25.60858, 152.96428 -25.60858, 152.96538 -25.60854, 152.96576 -25.6088)'
+        wkt = g.asWkt(5)
+        self.assertTrue(compareWkt(expWkt, wkt), "testReshape failed: mismatch Expected:\n%s\nGot:\n%s\n" % (expWkt, wkt))
+
     def testConvertToMultiType(self):
         """ Test converting geometries to multi type """
         point = QgsGeometry.fromWkt('Point (1 2)')