GTK_FILE_CHOOSER_ACTION_SAVE mode will present
a confirmation dialog if the user types a file name that already exists. This
is FALSE by default.gtkFileChooserSetDoOverwriteConfirmation(object, do.overwrite.confirmation)objectdo.overwrite.confirmationchooser will emit the
"confirm-overwrite" signal when appropriate.
If all you need is the stock confirmation dialog, set this property to TRUE.
You can override the way confirmation is done by actually handling the
"confirm-overwrite" signal; please refer to its documentation
for the details.
Since 2.8