diff --git a/src/libs/utils/fileutils.cpp b/src/libs/utils/fileutils.cpp
index fc539b044172b18eb40d9bd259aa0b1317cccbe8..15ab2755d6b24517e9c5a2e5523375873037ac08 100644
--- a/src/libs/utils/fileutils.cpp
+++ b/src/libs/utils/fileutils.cpp
@@ -526,10 +526,16 @@ bool FileName::operator>=(const FileName &other) const
 /// \returns whether FileName is a child of \a s
 bool FileName::isChildOf(const FileName &s) const
 {
+    if (s.isEmpty())
+        return false;
     if (!QString::startsWith(s, cs))
         return false;
     if (size() <= s.size())
         return false;
+    // s is root, '/' was already tested in startsWith
+    if (s.QString::endsWith(QLatin1Char('/')))
+        return true;
+    // s is a directory, next character should be '/' (/tmpdir is NOT a child of /tmp)
     return at(s.size()) == QLatin1Char('/');
 }
 
diff --git a/tests/auto/utils/fileutils/tst_fileutils.cpp b/tests/auto/utils/fileutils/tst_fileutils.cpp
index db8cc6274f4bbbb13240bcfce2c913eef31fa0c2..211ad166eac225cefea2992f364ca224bc470061 100644
--- a/tests/auto/utils/fileutils/tst_fileutils.cpp
+++ b/tests/auto/utils/fileutils/tst_fileutils.cpp
@@ -45,6 +45,8 @@ public:
 private slots:
     void parentDir_data();
     void parentDir();
+    void isChildOf_data();
+    void isChildOf();
 };
 
 void tst_fileutils::parentDir_data()
@@ -92,5 +94,43 @@ void tst_fileutils::parentDir()
     QCOMPARE(result.toString(), parentPath);
 }
 
+void tst_fileutils::isChildOf_data()
+{
+    QTest::addColumn<QString>("path");
+    QTest::addColumn<QString>("childPath");
+    QTest::addColumn<bool>("result");
+
+    QTest::newRow("empty path") << QString() << QString::fromLatin1("/tmp") << false;
+    QTest::newRow("root only") << QString::fromLatin1("/") << QString::fromLatin1("/tmp") << true;
+    QTest::newRow("/tmp/dir") << QString::fromLatin1("/tmp") << QString::fromLatin1("/tmp/dir") << true;
+    QTest::newRow("relative/path") << QString::fromLatin1("relative") << QString::fromLatin1("relative/path") << true;
+    QTest::newRow("/tmpdir") << QString::fromLatin1("/tmp") << QString::fromLatin1("/tmpdir") << false;
+    QTest::newRow("same") << QString::fromLatin1("/tmp/dir") << QString::fromLatin1("/tmp/dir") << false;
+
+    // Windows stuff:
+#ifdef Q_OS_WIN
+    QTest::newRow("C:/data") << QString::fromLatin1("C:/") << QString::fromLatin1("C:/data") << true;
+    QTest::newRow("C:/") << QString() << QString::fromLatin1("C:/") << false;
+    QTest::newRow("//./com1") << QString::fromLatin1("/") << QString::fromLatin1("//./com1") << true;
+    QTest::newRow("//?/path") << QString::fromLatin1("/") << QString::fromLatin1("//?/path") << true;
+    QTest::newRow("/Global??/UNC/host") << QString::fromLatin1("/Global??/UNC/host")
+                                        << QString::fromLatin1("/Global??/UNC/host/file") << true;
+    QTest::newRow("//server/directory/file")
+            << QString::fromLatin1("//server/directory") << QString::fromLatin1("//server/directory/file") << true;
+    QTest::newRow("//server/directory")
+            << QString::fromLatin1("//server") << QString::fromLatin1("//server/directory") << true;
+#endif
+}
+
+void tst_fileutils::isChildOf()
+{
+    QFETCH(QString, path);
+    QFETCH(QString, childPath);
+    QFETCH(bool, result);
+
+    bool res = FileName::fromString(childPath).isChildOf(FileName::fromString(path));
+    QCOMPARE(res, result);
+}
+
 QTEST_APPLESS_MAIN(tst_fileutils)
 #include "tst_fileutils.moc"