.then(function(stagedArchive) {
var comparator = new Comparator(mainArchive, stagedArchive),
differences = comparator.calculateDifferences();
var newHistoryMain = stripDestructiveCommands(differences.original),
newHistoryStaged = stripDestructiveCommands(differences.secondary),
base = differences.common;
var newArchive = new Archive();
newArchive._getWestley().clear();
base.concat(newHistoryStaged).concat(newHistoryMain).forEach(function(command) {
newArchive._getWestley().execute(command);
});
workspace.setArchive(newArchive);
return newArchive;
});
base.concat(newHistoryStaged).concat(newHistoryMain).forEach(function(command) {
newArchive._getWestley().execute(command);
});