Fix for qfsfileengine_win to return proper absolute path for C:\

When using canonicalPath on a QDir that currently just represents
a root directory, a valid path name such as "C:\" should be returned.
Previously we returned "C:" which in fact would point to the current
working directory on drive C: and therefor is not necessarily the same.

Reviewed-by: Thiago
Task-number: QTBUG-6680

2 files changed, 47 insertions, 4 deletions

diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index cc9b8c7..254c03e 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -1664,10 +1664,12 @@ QString QFSFileEngine::fileName(FileName file) const
 
         if (!isRelativePath()) {
 #if !defined(Q_OS_WINCE)
-            if ((d->filePath.size() > 2 && d->filePath.at(1) == QLatin1Char(':')
-                && d->filePath.at(2) != QLatin1Char('/')) || // It's a drive-relative path, so Z:a.txt -> Z:\currentpath\a.txt
-                d->filePath.startsWith(QLatin1Char('/'))    // It's a absolute path to the current drive, so \a.txt -> Z:\a.txt
-                ) {
+            if (d->filePath.startsWith(QLatin1Char('/')) || // It's a absolute path to the current drive, so \a.txt -> Z:\a.txt
+                d->filePath.size() == 2 ||                  // It's a drive letter that needs to get a working dir appended
+                (d->filePath.size() > 2 && d->filePath.at(2) != QLatin1Char('/')) || // It's a drive-relative path, so Z:a.txt -> Z:\currentpath\a.txt
+                d->filePath.contains(QLatin1String("/../")) || d->filePath.contains(QLatin1String("/./")) ||
+                d->filePath.endsWith(QLatin1String("/..")) || d->filePath.endsWith(QLatin1String("/.")))
+            {
                 ret = QDir::fromNativeSeparators(nativeAbsoluteFilePath(d->filePath));
             } else {
                 ret = d->filePath;
diff --git a/tests/auto/qdir/tst_qdir.cpp b/tests/auto/qdir/tst_qdir.cpp
index 71469bb..b2dc960 100644
--- a/tests/auto/qdir/tst_qdir.cpp
+++ b/tests/auto/qdir/tst_qdir.cpp
@@ -172,6 +172,11 @@ private slots:
     void longFileName();
 
     void updateFileLists();
+
+#if defined(Q_OS_WIN) || defined(Q_OS_SYMBIAN)
+    void isRoot_data();
+    void isRoot();
+#endif
 };
 
 // Testing get/set functions
@@ -805,6 +810,16 @@ void tst_QDir::canonicalPath_data()
     QTest::newRow("absPath") << appPath + "\\testData\\..\\testData" << appPath + "/testData";
 #endif
     QTest::newRow("nonexistant") << "testd" << QString();
+
+#if defined(Q_OS_WIN) || defined(Q_OS_SYMBIAN)
+    QTest::newRow("drive:/") << QDir::rootPath() << QDir::rootPath();
+    QTest::newRow("drive:\\") << QDir::toNativeSeparators(QDir::rootPath()) << QDir::rootPath();
+    QTest::newRow("drive:/./") << QDir::rootPath().append("./") << QDir::rootPath();
+    QTest::newRow("drive:/../.. ") << QDir::rootPath().append("../..") << QDir::rootPath();
+    QTest::newRow("drive:\\.\\") << QDir::toNativeSeparators(QDir::rootPath().append("./")) << QDir::rootPath();
+    QTest::newRow("drive:\\..\\..") << QDir::toNativeSeparators(QDir::rootPath().append("../..")) << QDir::rootPath();
+    QTest::newRow("drive:") << QDir::rootPath().left(2) << QDir::currentPath();
+#endif
 }
 
 void tst_QDir::canonicalPath()
@@ -1546,6 +1561,32 @@ void tst_QDir::updateFileLists()
     QCOMPARE(dir.entryList(), QStringList() << "sub-dir1" << "sub-dir2" << "file1.txt");
 }
 
+#if defined(Q_OS_WIN) || defined(Q_OS_SYMBIAN)
+void tst_QDir::isRoot_data()
+{
+    QTest::addColumn<QString>("path");
+    QTest::addColumn<bool>("isRoot");
+
+    QString test = QDir::rootPath();
+    QTest::newRow("rootPath " + test) << test << true;
+    test = QDir::rootPath().append("./");
+    QTest::newRow("./ appended " + test) << test << false;
+    test = QDir(QDir::rootPath().append("./")).canonicalPath();
+    QTest::newRow("canonicalPath " + test) << test << true;
+    test = QDir::rootPath().left(2);
+    QTest::newRow("drive relative " + test) << test << false;
+}
+
+void tst_QDir::isRoot()
+{
+    QFETCH(QString, path);
+    QFETCH(bool, isRoot);
+
+    QDir dir(path);
+    QCOMPARE(dir.isRoot(),isRoot);
+}
+#endif
+
 QTEST_MAIN(tst_QDir)
 #include "tst_qdir.moc"