diff --git a/src/utils/utils.cpp b/src/utils/utils.cpp
index 82108bc4..8cf0a93d 100644
--- a/src/utils/utils.cpp
+++ b/src/utils/utils.cpp
@@ -803,6 +803,10 @@ int digitalCompare(const QString &left, const QString &right)
     int ret = 0;
     if (left.compare(right) == 0)
         return ret;
+    if (left.size() == 0)
+        return -1;
+    if (right.size() == 0)
+        return 1;
 
     QString left_sub = left;
     QString right_sub = right;
diff --git a/src/utils/utils.h b/src/utils/utils.h
index f0ff924e..1726a15f 100644
--- a/src/utils/utils.h
+++ b/src/utils/utils.h
@@ -94,4 +94,5 @@ QByteArray buildFormData(const QHash<QString, QString>& params);
 int digitalCompare(const QString &left, const QString &right);
 
 bool shouldUseFramelessWindow();
+
 #endif
diff --git a/tests/test_utils.cpp b/tests/test_utils.cpp
index 3450e6f6..4de82a83 100644
--- a/tests/test_utils.cpp
+++ b/tests/test_utils.cpp
@@ -1,8 +1,18 @@
 #include "test_utils.h"
 #include <QtTest/QtTest>
+#include <algorithm>            // std::sort
 
 #include "../src/utils/utils.h"
 
+namespace {
+
+bool digitalCompareFileByName(const QString& a, const QString& b)
+{
+    return digitalCompare(a, b) < 0 ? true : false;
+}
+
+} // namespace
+
 void Utils::testReadableFileSize() {
     QCOMPARE(::readableFileSize(0), QString("0B"));
     QCOMPARE(::readableFileSize(1000), QString("1KB"));
@@ -43,11 +53,48 @@ void Utils::testIncludeUrlParams() {
 }
 
 void Utils::testDigitalCompare() {
+    QList<QString> list;
+    list << "05 copy 2.ico" << "05 copy 3.ico"
+         << "05 copy.ico" << "05.ico"
+         << "34th TOPIK Papers - Advanced level 2.pdf"
+         << "34th TOPIK Papers - Advanced level.pdf"
+         << "A1/" << "B1/" << "a2/" << "b2/"
+         << "IMG_20140523_171911 - 副本.jpg"
+         << "IMG_20140523_171911.jpg"
+         << "MIT18_06SCF11_Ses3.1sum.pdf" << "Paraffin.exe"
+         << "Screen Shot 2016-08-13 at 11.42.35 PM.png"
+         << "Screen Shot 2016-09-02 at 4.47.12 PM.png"
+         << "WixDependencyExtension.dll"
+         << "darice - 副本 - 副本.cub"
+         << "darice - 副本.cub" << "darice.cub"
+         << "depends.chm" << "depends.exe"
+         << "dokan-build - 副本.log" << "dokan-build.log"
+         << "dokan-build copy 2 - 副本(2).log"
+         << "dokan-build copy 2 - 副本.log"
+         << "dokan-build copy 2.log"
+         << "dokan-build copy 3.log"
+         << "dokan-build copy.log"
+         << "heat.exe" << "heat.exe.config"
+         << "new copy.txt" << "new.txt"
+         << "require(1).js" << "require.js"
+         << "subfolder1/" << "untitled folder/"
+         << "whole-stage-codegen.pdf" << "wix.dll"
+         << "x copy 10.md" << "x copy.md"
+         << "x copy 2.md" << "x copy 3.md"
+         << "新建文本文档.txt"
+         << "新建文本文档 copy.txt"
+         << "新建文本文档 - 副本.txt"
+         << "新建文本文档(2).txt"
+         << "新建文本文档(3).txt";
+    std::sort(list.begin(), list.end(), digitalCompareFileByName);
+
     QCOMPARE(::digitalCompare("9", "9"), 0);
     QCOMPARE(::digitalCompare("aa9aa", "aa9aa"), 0);
     QCOMPARE(::digitalCompare("99a99", "99a99"), 0);
     QCOMPARE(::digitalCompare("9", "11"), -2);
     QCOMPARE(::digitalCompare("1.9", "1.11"), -2);
+    QCOMPARE(::digitalCompare("1 9", "1 11"), -2);
+    QCOMPARE(::digitalCompare("1abc1", "1abc1.abc"), -1);
     QCOMPARE(::digitalCompare("1.1.1.1.9", "1.1.1.1.11"), -2);
     QCOMPARE(::digitalCompare("a9", "a11"), -2);
     QCOMPARE(::digitalCompare("a9aaa", "a11aaa"), -2);