Fix assert with negative QVector size in transformBoundingBox

This fixes #32302 by insuring that the multilication of nXPoints and nYPoints doesn't result in overflown (and threfore negative) int value
qgis · Oct 18, 2019 · f393c11 · f393c11
1 parent a11903a
commit f393c11
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/src/core/qgscoordinatetransform.cpp b/src/core/qgscoordinatetransform.cpp
@@ -491,19 +491,18 @@ QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle &r
 
   // 64 points (<=2.12) is not enough, see #13665, for EPSG:4326 -> EPSG:3574 (say that it is a hard one),
   // are decent result from about 500 points and more. This method is called quite often, but
-  // even with 1000 points it takes < 1ms
+  // even with 1000 points it takes < 1ms.
   // TODO: how to effectively and precisely reproject bounding box?
   const int nPoints = 1000;
   double d = std::sqrt( ( rect.width() * rect.height() ) / std::pow( std::sqrt( static_cast< double >( nPoints ) ) - 1, 2.0 ) );
-  int nXPoints = static_cast< int >( std::ceil( rect.width() / d ) ) + 1;
-  int nYPoints = static_cast< int >( std::ceil( rect.height() / d ) ) + 1;
+  int nXPoints = std::min( static_cast< int >( std::ceil( rect.width() / d ) ) + 1, 1000 );
+  int nYPoints = std::min( static_cast< int >( std::ceil( rect.height() / d ) ) + 1, 1000 );
 
   QgsRectangle bb_rect;
   bb_rect.setMinimal();
 
   // We're interfacing with C-style vectors in the
   // end, so let's do C-style vectors here too.
-
   QVector<double> x( nXPoints * nYPoints );
   QVector<double> y( nXPoints * nYPoints );
   QVector<double> z( nXPoints * nYPoints );