show warning when user tried to create field 'shape' in shapefile (fix #3201)

Author: alexbruy

src/app/qgsaddattrdialog.cpp

@@ -20,13 +20,16 @@
 #include "qgsvectordataprovider.h"
 #include "qgslogger.h"
 
+#include <QMessageBox>
+
 QgsAddAttrDialog::QgsAddAttrDialog( QgsVectorLayer *vlayer, QWidget *parent, Qt::WFlags fl )
     : QDialog( parent, fl )
 {
   setupUi( this );
 
   //fill data types into the combo box
   const QList< QgsVectorDataProvider::NativeType > &typelist = vlayer->dataProvider()->nativeTypes();
+  mLayerType = vlayer->storageType();
 
   for ( int i = 0; i < typelist.size(); i++ )
   {
@@ -70,6 +73,17 @@ void QgsAddAttrDialog::on_mTypeBox_currentIndexChanged( int idx )
     mPrec->setValue( mPrec->maximum() );
 }
 
+void QgsAddAttrDialog::accept()
+{
+  if ( mLayerType == "ESRI Shapefile" && mNameEdit->text().toLower() == "shape" )
+  {
+    QMessageBox::warning( this, tr( "Warning" ),
+                          tr( "Invalid field name. This field name is reserved and cannot be used." ) );
+    return;
+  }
+  QDialog::accept();
+}
+
 QgsField QgsAddAttrDialog::field() const
 {
   QgsDebugMsg( QString( "idx:%1 name:%2 type:%3 typeName:%4 length:%5 prec:%6 comment:%7" )

src/app/qgsaddattrdialog.h

@@ -37,6 +37,10 @@ class QgsAddAttrDialog: public QDialog, private Ui::QgsAddAttrDialogBase
 
   public slots:
     void on_mTypeBox_currentIndexChanged( int idx );
+    void accept();
+
+  private:
+    QString mLayerType;
 
 };