winrt: msvc2015: refactor file handling

msvc2015 reintroduced a couple of functions from the win32 API
towards WinRT.

Enable usage of those and simplify the file system engine.
Furthermore update the autotests.

Change-Id: I9eafffba0ddfd05917c184c4a6b9e166f86d71d9
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>

6 files changed, 49 insertions, 12 deletions

diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index 4d2b36632f..2c2bdd579e 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -152,7 +152,11 @@ inline void QDirPrivate::setPath(const QString &path)
     if (p.endsWith(QLatin1Char('/'))
             && p.length() > 1
 #if defined(Q_OS_WIN)
+#  if defined (Q_OS_WINRT)
+        && (!(p.toLower() == QDir::rootPath().toLower()))
+#  else
         && (!(p.length() == 3 && p.at(1).unicode() == ':' && p.at(0).isLetter()))
+#  endif
 #endif
     ) {
             p.truncate(p.length() - 1);
@@ -885,6 +889,9 @@ bool QDir::cd(const QString &dirName)
 #if defined (Q_OS_UNIX)
             //After cleanPath() if path is "/.." or starts with "/../" it means trying to cd above root.
             if (newPath.startsWith(QLatin1String("/../")) || newPath == QLatin1String("/.."))
+#elif defined (Q_OS_WINRT)
+            const QString rootPath = QDir::rootPath();
+            if (newPath.size() < rootPath.size() && rootPath.startsWith(newPath))
 #else
             /*
               cleanPath() already took care of replacing '\' with '/'.
@@ -2187,7 +2194,11 @@ QString QDir::cleanPath(const QString &path)
     // Strip away last slash except for root directories
     if (ret.length() > 1 && ret.endsWith(QLatin1Char('/'))) {
 #if defined (Q_OS_WIN)
+#  if defined(Q_OS_WINRT)
+        if (!((ret.length() == 3 || ret.length() == QDir::rootPath().length()) && ret.at(1) == QLatin1Char(':')))
+#  else
         if (!(ret.length() == 3 && ret.at(1) == QLatin1Char(':')))
+#  endif
 #endif
             ret.chop(1);
     }
diff --git a/src/corelib/io/qfileinfo.cpp b/src/corelib/io/qfileinfo.cpp
index 51b39b1114..dd194594c9 100644
--- a/src/corelib/io/qfileinfo.cpp
+++ b/src/corelib/io/qfileinfo.cpp
@@ -1095,7 +1095,7 @@ bool QFileInfo::isRoot() const
         return true;
     if (d->fileEngine == 0) {
         if (d->fileEntry.isRoot()) {
-#if defined(Q_OS_WIN)
+#if defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
             //the path is a drive root, but the drive may not exist
             //for backward compatibility, return true only if the drive exists
             if (!d->cache_enabled || !d->metaData.hasFlags(QFileSystemMetaData::ExistsAttribute))
diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index 379095a83d..f1a6019094 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -78,6 +78,11 @@ using namespace Microsoft::WRL::Wrappers;
 using namespace ABI::Windows::Foundation;
 using namespace ABI::Windows::Storage;
 using namespace ABI::Windows::ApplicationModel;
+
+#if _MSC_VER < 1900
+#define Q_OS_WINRT_WIN81
+#endif
+
 #endif // Q_OS_WINRT
 
 #ifndef SPI_GETPLATFORMTYPE
@@ -522,7 +527,7 @@ QString QFileSystemEngine::nativeAbsoluteFilePath(const QString &path)
 {
     // can be //server or //server/share
     QString absPath;
-#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT)
+#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT_WIN81)
     QVarLengthArray<wchar_t, MAX_PATH> buf(qMax(MAX_PATH, path.size() + 1));
     wchar_t *fileName = 0;
     DWORD retLen = GetFullPathName((wchar_t*)path.utf16(), buf.size(), buf.data(), &fileName);
@@ -532,6 +537,16 @@ QString QFileSystemEngine::nativeAbsoluteFilePath(const QString &path)
     }
     if (retLen != 0)
         absPath = QString::fromWCharArray(buf.data(), retLen);
+#  if defined(Q_OS_WINRT)
+    // Win32 returns eg C:/ as root directory with a trailing /.
+    // WinRT returns the sandbox root without /.
+    // Also C:/../.. returns C:/ on Win32, while for WinRT it steps outside the package
+    // and goes beyond package root. Hence force the engine to stay inside
+    // the package.
+    const QString rootPath = QDir::toNativeSeparators(QDir::rootPath());
+    if (absPath.size() < rootPath.size() && rootPath.startsWith(absPath))
+        absPath = rootPath;
+#  endif // Q_OS_WINRT
 #elif !defined(Q_OS_WINCE)
     if (QDir::isRelativePath(path))
         absPath = QDir::toNativeSeparators(QDir::cleanPath(QDir::currentPath() + QLatin1Char('/') + path));
@@ -569,7 +584,7 @@ QFileSystemEntry QFileSystemEngine::absoluteName(const QFileSystemEntry &entry)
         ret = entry.filePath();
 #endif
     } else {
-#ifndef Q_OS_WINRT
+#ifndef Q_OS_WINRT_WIN81
         ret = QDir::cleanPath(QDir::currentPath() + QLatin1Char('/') + entry.filePath());
 #else
         // Some WinRT APIs do not support absolute paths (due to sandboxing).
@@ -1218,8 +1233,8 @@ QString QFileSystemEngine::rootPath()
     if (FAILED(item->get_Path(finalWinPath.GetAddressOf())))
         return ret;
 
-    ret = QDir::fromNativeSeparators(QString::fromWCharArray(finalWinPath.GetRawBuffer(nullptr)));
-
+    const QString qtWinPath = QDir::fromNativeSeparators(QString::fromWCharArray(finalWinPath.GetRawBuffer(nullptr)));
+    ret = qtWinPath.endsWith(QLatin1Char('/')) ? qtWinPath : qtWinPath + QLatin1Char('/');
 #else
     QString ret = QString::fromLatin1(qgetenv("SystemDrive"));
     if (ret.isEmpty())
@@ -1337,7 +1352,7 @@ bool QFileSystemEngine::setCurrentPath(const QFileSystemEntry &entry)
     if(!(meta.exists() && meta.isDirectory()))
         return false;
 
-#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT)
+#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT_WIN81)
     //TODO: this should really be using nativeFilePath(), but that returns a path in long format \\?\c:\foo
     //which causes many problems later on when it's returned through currentPath()
     return ::SetCurrentDirectory(reinterpret_cast<const wchar_t*>(QDir::toNativeSeparators(entry.filePath()).utf16())) != 0;
@@ -1350,7 +1365,7 @@ bool QFileSystemEngine::setCurrentPath(const QFileSystemEntry &entry)
 QFileSystemEntry QFileSystemEngine::currentPath()
 {
     QString ret;
-#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT)
+#if !defined(Q_OS_WINCE) && !defined(Q_OS_WINRT_WIN81)
     DWORD size = 0;
     wchar_t currentName[PATH_MAX];
     size = ::GetCurrentDirectory(PATH_MAX, currentName);
@@ -1366,17 +1381,17 @@ QFileSystemEntry QFileSystemEngine::currentPath()
     }
     if (ret.length() >= 2 && ret[1] == QLatin1Char(':'))
         ret[0] = ret.at(0).toUpper(); // Force uppercase drive letters.
-#else // !Q_OS_WINCE && !Q_OS_WINRT
+#else // !Q_OS_WINCE && !Q_OS_WINRT_WIN81
     //TODO - a race condition exists when using currentPath / setCurrentPath from multiple threads
     if (qfsPrivateCurrentDir.isEmpty())
-#ifndef Q_OS_WINRT
+#ifndef Q_OS_WINRT_WIN81
         qfsPrivateCurrentDir = QCoreApplication::applicationDirPath();
 #else
         qfsPrivateCurrentDir = QDir::rootPath();
 #endif
 
     ret = qfsPrivateCurrentDir;
-#endif // Q_OS_WINCE || Q_OS_WINRT
+#endif // Q_OS_WINCE || Q_OS_WINRT_WIN81
     return QFileSystemEntry(ret, QFileSystemEntry::FromNativePath());
 }
 
diff --git a/src/corelib/io/qfilesystementry.cpp b/src/corelib/io/qfilesystementry.cpp
index 709970e3ac..c590d81f7a 100644
--- a/src/corelib/io/qfilesystementry.cpp
+++ b/src/corelib/io/qfilesystementry.cpp
@@ -166,6 +166,12 @@ void QFileSystemEntry::resolveNativeFilePath() const
             m_nativeFilePath.remove(0,1);
         if (m_nativeFilePath.isEmpty())
             m_nativeFilePath.append(QLatin1Char('.'));
+        // WinRT/MSVC2015 allows a maximum of 256 characters for a filepath
+        // unless //?/ is prepended which extends the rule to have a maximum
+        // of 256 characters in the filename plus the preprending path
+#if _MSC_VER >= 1900
+        m_nativeFilePath.prepend("\\\\?\\");
+#endif
 #endif
     }
 }
@@ -283,9 +289,13 @@ bool QFileSystemEntry::isAbsolute() const
 bool QFileSystemEntry::isDriveRoot() const
 {
     resolveFilePath();
+#ifndef Q_OS_WINRT
     return (m_filePath.length() == 3
            && m_filePath.at(0).isLetter() && m_filePath.at(1) == QLatin1Char(':')
            && m_filePath.at(2) == QLatin1Char('/'));
+#else // !Q_OS_WINRT
+    return m_filePath == QDir::rootPath();
+#endif // !Q_OS_WINRT
 }
 #endif
 
diff --git a/src/corelib/io/qfilesystemiterator_win.cpp b/src/corelib/io/qfilesystemiterator_win.cpp
index 6351a3559d..d7fed87222 100644
--- a/src/corelib/io/qfilesystemiterator_win.cpp
+++ b/src/corelib/io/qfilesystemiterator_win.cpp
@@ -67,7 +67,8 @@ QFileSystemIterator::QFileSystemIterator(const QFileSystemEntry &entry, QDir::Fi
     if (!nativePath.endsWith(QLatin1Char('\\')))
         nativePath.append(QLatin1Char('\\'));
     nativePath.append(QLatin1Char('*'));
-#ifdef Q_OS_WINRT
+    // In MSVC2015+ case we prepend //?/ for longer file-name support
+#if defined(Q_OS_WINRT) && _MSC_VER < 1900
     if (nativePath.startsWith(QLatin1Char('\\')))
         nativePath.remove(0, 1);
 #endif
diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index cfd50955a6..886d526fb1 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -1037,7 +1037,7 @@ uchar *QFSFileEnginePrivate::map(qint64 offset, qint64 size,
                                       offsetHi, offsetLo, size + extra);
 #else
     LPVOID mapAddress = ::MapViewOfFileFromApp(mapHandle, access,
-                                               (ULONG64(offsetHi) << 32) + offsetLo, size);
+                                               (ULONG64(offsetHi) << 32) + offsetLo, size + extra);
 #endif
     if (mapAddress) {
         uchar *address = extra + static_cast<uchar*>(mapAddress);