[bugfix] Prevent a bad crash when provider is wrong

elpaso · elpaso · commit 2523d7351cf1 · 2017-11-07T09:26:01.000+01:00
Fixes #17155
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -1530,12 +1530,8 @@ bool QgsVectorLayer::setDataProvider( QString const &provider )
     dataSource = uri.uri( false );
   }
 
-  // XXX when execution gets here.
-
-  //XXX - This was a dynamic cast but that kills the Windows
-  //      version big-time with an abnormal termination error
   delete mDataProvider;
-  mDataProvider = ( QgsVectorDataProvider * )( QgsProviderRegistry::instance()->createProvider( provider, dataSource ) );
+  mDataProvider = qobject_cast<QgsVectorDataProvider *>( QgsProviderRegistry::instance()->createProvider( provider, dataSource ) );
   if ( !mDataProvider )
   {
     QgsDebugMsg( " unable to get data provider" );

Original file line number	Diff line number	Diff line change
`@@ -1530,12 +1530,8 @@ bool QgsVectorLayer::setDataProvider( QString const &provider )`
`1530`	`1530`	`dataSource = uri.uri( false );`
`1531`	`1531`	`}`
`1532`	`1532`
`1533`		`- // XXX when execution gets here.`
`1534`		`-`
`1535`		`- //XXX - This was a dynamic cast but that kills the Windows`
`1536`		`- // version big-time with an abnormal termination error`
`1537`	`1533`	`delete mDataProvider;`
`1538`		`- mDataProvider = ( QgsVectorDataProvider * )( QgsProviderRegistry::instance()->createProvider( provider, dataSource ) );`
	`1534`	`+ mDataProvider = qobject_cast<QgsVectorDataProvider *>( QgsProviderRegistry::instance()->createProvider( provider, dataSource ) );`
`1539`	`1535`	`if ( !mDataProvider )`
`1540`	`1536`	`{`
`1541`	`1537`	`QgsDebugMsg( " unable to get data provider" );`