Fix use after free when rendering 3d linestrings

nyalldawson · nyalldawson · commit 03162f422718 · 2023-04-18T13:20:29.000+10:00
diff --git a/src/core/symbology/qgssymbol.cpp b/src/core/symbology/qgssymbol.cpp
@@ -104,13 +104,13 @@ QPolygonF QgsSymbol::_getLineString3d( QgsRenderContext &context, const QgsCurve
     const QgsBox3d clipRect( e.xMinimum() - cw, e.yMinimum() - ch, -HUGE_VAL, e.xMaximum() + cw, e.yMaximum() + ch, HUGE_VAL ); // TODO also need to be clipped according to z axis
 
     const QgsLineString *lineString = nullptr;
+    std::unique_ptr< QgsLineString > segmentized;
     if ( const QgsLineString *ls = qgsgeometry_cast< const QgsLineString * >( &curve ) )
     {
       lineString = ls;
     }
     else
     {
-      std::unique_ptr< QgsLineString > segmentized;
       segmentized.reset( qgsgeometry_cast< QgsLineString * >( curve.segmentize( ) ) );
       lineString = segmentized.get();
     }

Original file line number	Diff line number	Diff line change
`@@ -104,13 +104,13 @@ QPolygonF QgsSymbol::_getLineString3d( QgsRenderContext &context, const QgsCurve`
`104`	`104`	`const QgsBox3d clipRect( e.xMinimum() - cw, e.yMinimum() - ch, -HUGE_VAL, e.xMaximum() + cw, e.yMaximum() + ch, HUGE_VAL ); // TODO also need to be clipped according to z axis`
`105`	`105`
`106`	`106`	`const QgsLineString *lineString = nullptr;`
	`107`	`+ std::unique_ptr< QgsLineString > segmentized;`
`107`	`108`	`if ( const QgsLineString ls = qgsgeometry_cast< const QgsLineString >( &curve ) )`
`108`	`109`	`{`
`109`	`110`	`lineString = ls;`
`110`	`111`	`}`
`111`	`112`	`else`
`112`	`113`	`{`
`113`		`- std::unique_ptr< QgsLineString > segmentized;`
`114`	`114`	`segmentized.reset( qgsgeometry_cast< QgsLineString * >( curve.segmentize( ) ) );`
`115`	`115`	`lineString = segmentized.get();`
`116`	`116`	`}`