Natural Breaks (Jenks) classification causes crash (#42618)

tomass · nyalldawson · commit d2dff9b5cd5d · 2021-04-07T12:29:01.000+10:00
diff --git a/src/core/classification/qgsclassificationjenks.cpp b/src/core/classification/qgsclassificationjenks.cpp
@@ -99,10 +99,11 @@ QList<double> QgsClassificationJenks::calculateBreaks( double &minimum, double &
 
 #if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
       double r = QRandomGenerator::global()->generate();
+      int j = std::floor( r / QRandomGenerator::max() * ( values.size() - 1 ) );
 #else
       double r = qrand();
-#endif
       int j = std::floor( r / RAND_MAX * ( values.size() - 1 ) );
+#endif
       sample[ i ] = values[ j ];
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -99,10 +99,11 @@ QList<double> QgsClassificationJenks::calculateBreaks( double &minimum, double &`
`99`	`99`
`100`	`100`	`#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)`
`101`	`101`	`double r = QRandomGenerator::global()->generate();`
	`102`	`+ int j = std::floor( r / QRandomGenerator::max() * ( values.size() - 1 ) );`
`102`	`103`	`#else`
`103`	`104`	`double r = qrand();`
`104`		`-#endif`
`105`	`105`	`int j = std::floor( r / RAND_MAX * ( values.size() - 1 ) );`
	`106`	`+#endif`
`106`	`107`	`sample[ i ] = values[ j ];`
`107`	`108`	`}`
`108`	`109`	`}`