attribute table: allow toggling editing if layer is capabable of any change, not only attributes (fixes #7504)

Author: jef-n

src/app/qgisapp.cpp

@@ -3641,7 +3641,7 @@ void QgisApp::newVectorLayer()
     //todo: the last parameter will change accordingly to layer type
     addVectorLayers( fileNames, enc, "file" );
   }
-  else if( fileName.isNull() )
+  else if ( fileName.isNull() )
   {
     QLabel *msgLabel = new QLabel( tr( "Layer creation failed. Please check the <a href=\"#messageLog\">message log</a> for further information." ), messageBar() );
     msgLabel->setWordWrap( true );

src/app/qgsattributetabledialog.cpp

@@ -168,10 +168,10 @@ QgsAttributeTableDialog::QgsAttributeTableDialog( QgsVectorLayer *theLayer, QWid
   mToggleEditingButton->blockSignals( true );
   mToggleEditingButton->setCheckable( true );
   mToggleEditingButton->setChecked( mLayer->isEditable() );
-  mToggleEditingButton->setEnabled( canChangeAttributes && !mLayer->isReadOnly() );
+  mToggleEditingButton->setEnabled(( canChangeAttributes || canDeleteFeatures || canAddAttributes || canDeleteAttributes || canAddFeatures ) && !mLayer->isReadOnly() );
   mToggleEditingButton->blockSignals( false );
 
-  mSaveEditsButton->setEnabled( canChangeAttributes && mLayer->isEditable() );
+  mSaveEditsButton->setEnabled( mToggleEditingButton->isEnabled() && mLayer->isEditable() );
   mOpenFieldCalculator->setEnabled(( canChangeAttributes || canAddAttributes ) && mLayer->isEditable() );
   mDeleteSelectedButton->setEnabled( canDeleteFeatures && mLayer->isEditable() );
   mAddAttribute->setEnabled( canAddAttributes && mLayer->isEditable() );