Support Windows .lnk files with VFS Cf API.

src/common/filesystembase.cpp

@@ -1,4 +1,4 @@
 /*
  * Copyright (C) by Daniel Molkentin <[email protected]>
  *
  * This library is free software; you can redistribute it and/or
@@ -52,8 +52,11 @@
 
 void FileSystem::setFileHidden(const QString &filename, bool hidden)
 {
+    if (filename.isEmpty()) {
+        return;
+    }
 #ifdef _WIN32
-    QString fName = longWinPath(filename);
+    const QString fName = longWinPath(filename);
     DWORD dwAttrs = 0;
 
     dwAttrs = GetFileAttributesW((wchar_t *)fName.utf16());
@@ -71,6 +74,24 @@
 #endif
 }
 
+bool FileSystem::isFileHidden(const QString &filename)
+{
+#ifdef _WIN32
+    if (isLnkFile(filename)) {
+        const QString fName = longWinPath(filename);
+        DWORD dwAttrs = 0;
+
+        dwAttrs = GetFileAttributesW((wchar_t *)fName.utf16());
+
+        if (dwAttrs == INVALID_FILE_ATTRIBUTES) {
+            return false;
+        }
+        return dwAttrs & FILE_ATTRIBUTE_HIDDEN;
+    }
+#endif
+    return QFileInfo(filename).isHidden();
+}
+
 static QFile::Permissions getDefaultWritePermissions()
 {
     QFile::Permissions result = QFile::WriteUser;
@@ -89,11 +110,27 @@
 
 void FileSystem::setFileReadOnly(const QString &filename, bool readonly)
 {
+#ifdef  Q_OS_WIN
+    if (isLnkFile(filename)) {
+        if (!fileExists(filename)) {
+            return;
+        }
+        const auto permissions = filePermissionsWin(filename);
+
+        std::filesystem::perms allWritePermissions = std::filesystem::perms::_All_write;
+        static std::filesystem::perms defaultWritePermissions = std::filesystem::perms::others_write;
+
+        std::filesystem::permissions(filename.toStdString(), allWritePermissions, std::filesystem::perm_options::remove);
+
+        if (!readonly) {
+            std::filesystem::permissions(filename.toStdString(), defaultWritePermissions, std::filesystem::perm_options::add);
+        }
+    }
+#endif
     QFile file(filename);
     QFile::Permissions permissions = file.permissions();
 
-    QFile::Permissions allWritePermissions =
-        QFile::WriteUser | QFile::WriteGroup | QFile::WriteOther | QFile::WriteOwner;
+    QFile::Permissions allWritePermissions = QFile::WriteUser | QFile::WriteGroup | QFile::WriteOther | QFile::WriteOwner;
     static QFile::Permissions defaultWritePermissions = getDefaultWritePermissions();
 
     permissions &= ~allWritePermissions;
@@ -116,6 +153,18 @@
 
 bool FileSystem::setFileReadOnlyWeak(const QString &filename, bool readonly)
 {
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        const auto permissions = filePermissionsWin(filename);
+
+        if (!readonly && static_cast<bool>((permissions & std::filesystem::perms::owner_write))) {
+            return false; // already writable enough
+        }
+
+        setFileReadOnly(filename, readonly);
+        return true;
+    }
+#endif
     QFile file(filename);
     QFile::Permissions permissions = file.permissions();
 
@@ -193,7 +242,7 @@
 
 #else //Q_OS_WIN
     // You can not overwrite a read-only file on windows.
-    if (!QFileInfo(destinationFileName).isWritable()) {
+    if (!isWritable(destinationFileName)) {
         setFileReadOnly(destinationFileName, false);
     }
 
@@ -289,11 +338,24 @@
 }
 
 #ifdef Q_OS_WIN
+std::filesystem::perms FileSystem::filePermissionsWin(const QString &filename)
+{
+    return std::filesystem::status(filename.toStdString()).permissions();
+}
+
+void FileSystem::setFilePermissionsWin(const QString &filename, const std::filesystem::perms &perms)
+{
+    if (!fileExists(filename)) {
+        return;
+    }
+    std::filesystem::permissions(filename.toStdString(), perms);
+}
+
 static bool fileExistsWin(const QString &filename)
 {
     WIN32_FIND_DATA FindFileData;
     HANDLE hFind = nullptr;
-    QString fName = FileSystem::longWinPath(filename);
+    const QString fName = FileSystem::longWinPath(filename);
 
     hFind = FindFirstFileW((wchar_t *)fName.utf16(), &FindFileData);
     if (hFind == INVALID_HANDLE_VALUE) {
@@ -302,6 +364,25 @@
     FindClose(hFind);
     return true;
 }
+
+static bool isDirWin(const QString &filename)
+{
+    WIN32_FIND_DATA FindFileData;
+    HANDLE hFind = nullptr;
+    const QString fName = FileSystem::longWinPath(filename);
+
+    hFind = FindFirstFileW((wchar_t *)fName.utf16(), &FindFileData);
+    if (hFind == INVALID_HANDLE_VALUE) {
+        return false;
+    }
+    FindClose(hFind);
+    return FindFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
+}
+
+static bool isFileWin(const QString &filename)
+{
+    return !isDirWin(filename);
+}
 #endif
 
 bool FileSystem::fileExists(const QString &filename, const QFileInfo &fileInfo)
@@ -323,6 +404,100 @@
     return re;
 }
 
+bool FileSystem::isDir(const QString &filename, const QFileInfo &fileInfo)
+{
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        // Use a native check.
+        return isDirWin(filename);
+    }
+#endif
+    bool re = fileInfo.isDir();
+    // if the filename is different from the filename in fileInfo, the fileInfo is
+    // not valid. There needs to be one initialised here. Otherwise the incoming
+    // fileInfo is re-used.
+    if (fileInfo.filePath() != filename) {
+        QFileInfo myFI(filename);
+        re = myFI.isDir();
+    }
+    return re;
+}
+
+bool FileSystem::isFile(const QString &filename, const QFileInfo &fileInfo)
+{
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        // Use a native check.
+        return isFileWin(filename);
+    }
+#endif
+    bool re = fileInfo.isDir();
+    // if the filename is different from the filename in fileInfo, the fileInfo is
+    // not valid. There needs to be one initialised here. Otherwise the incoming
+    // fileInfo is re-used.
+    if (fileInfo.filePath() != filename) {
+        QFileInfo myFI(filename);
+        re = myFI.isFile();
+    }
+    return re;
+}
+
+bool FileSystem::isWritable(const QString &filename, const QFileInfo &fileInfo)
+{
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        const auto permissions = filePermissionsWin(filename);
+        return static_cast<bool>((permissions & std::filesystem::perms::owner_write));
+    }
+#endif
+    bool re = fileInfo.isWritable();
+    // if the filename is different from the filename in fileInfo, the fileInfo is
+    // not valid. There needs to be one initialised here. Otherwise the incoming
+    // fileInfo is re-used.
+    if (fileInfo.filePath() != filename) {
+        QFileInfo myFI(filename);
+        re = myFI.isWritable();
+    }
+    return re;
+}
+
+bool FileSystem::isReadable(const QString &filename, const QFileInfo &fileInfo)
+{
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        const auto permissions = filePermissionsWin(filename);
+        return static_cast<bool>((permissions & std::filesystem::perms::owner_read));
+    }
+#endif
+    bool re = fileInfo.isReadable();
+    // if the filename is different from the filename in fileInfo, the fileInfo is
+    // not valid. There needs to be one initialised here. Otherwise the incoming
+    // fileInfo is re-used.
+    if (fileInfo.filePath() != filename) {
+        QFileInfo myFI(filename);
+        re = myFI.isReadable();
+    }
+    return re;
+}
+
+bool FileSystem::isSymLink(const QString &filename, const QFileInfo &fileInfo)
+{
+#ifdef Q_OS_WIN
+    if (isLnkFile(filename)) {
+        return isJunction(filename);
+    }
+#endif
+    bool re = fileInfo.isSymLink();
+    // if the filename is different from the filename in fileInfo, the fileInfo is
+    // not valid. There needs to be one initialised here. Otherwise the incoming
+    // fileInfo is re-used.
+    if (fileInfo.filePath() != filename) {
+        QFileInfo myFI(filename);
+        re = myFI.isSymLink();
+    }
+    return re;
+}
+
 #ifdef Q_OS_WIN
 QString FileSystem::fileSystemForPath(const QString &path)
 {
@@ -351,7 +526,7 @@
 #ifdef Q_OS_WIN
     // You cannot delete a read-only file on windows, but we want to
     // allow that.
-    if (!QFileInfo(fileName).isWritable()) {
+    if (!isWritable(fileName)) {
         setFileReadOnly(fileName, false);
     }
 #endif

src/common/filesystembase.h

@@ -1,4 +1,4 @@
 /*
  * Copyright (C) by Olivier Goffart <[email protected]>
  *
  * This library is free software; you can redistribute it and/or
@@ -18,7 +18,7 @@
 
 #pragma once
 
 #include "config.h"
 
 #include "csync/ocsynclib.h"
 
@@ -28,7 +28,11 @@
 
 #include <ctime>
 
+#if !defined(Q_OS_MACOS) || __MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_15
+#include <filesystem>
+#endif
+
 class QFile;
 
 namespace OCC {
 
@@ -53,6 +57,8 @@
      */
     void OCSYNC_EXPORT setFileHidden(const QString &filename, bool hidden);
 
+    bool OCSYNC_EXPORT isFileHidden(const QString &filename);
+
     /**
      * @brief Marks the file as read-only.
      *
@@ -89,6 +95,34 @@
      */
     bool OCSYNC_EXPORT fileExists(const QString &filename, const QFileInfo & = QFileInfo());
 
+    /**
+     * @brief Checks whether it is a dir.
+     *
+     * Use this over QFileInfo::isDir() and QFile::isDir() to avoid bugs with lnk
+     * files, see above.
+     */
+    bool OCSYNC_EXPORT isDir(const QString &filename, const QFileInfo& = QFileInfo());
+
+    /**
+     * @brief Checks whether it is a file.
+     *
+     * Use this over QFileInfo::isDir() and QFile::isDir() to avoid bugs with lnk
+     * files, see above.
+     */
+    bool OCSYNC_EXPORT isFile(const QString &filename, const QFileInfo& fileInfo = QFileInfo());
+
+    /**
+     * @brief Checks whether the file is writable.
+     *
+     * Use this over QFileInfo::isDir() and QFile::isDir() to avoid bugs with lnk
+     * files, see above.
+     */
+    bool OCSYNC_EXPORT isWritable(const QString &filename, const QFileInfo &fileInfo = QFileInfo());
+
+    bool OCSYNC_EXPORT isReadable(const QString &filename, const QFileInfo &fileInfo = QFileInfo());
+
+    bool OCSYNC_EXPORT isSymLink(const QString &filename, const QFileInfo &fileInfo = QFileInfo());
+
     /**
      * @brief Rename the file \a originFileName to \a destinationFileName.
      *
@@ -146,6 +180,9 @@
      *    the windows API functions work with the normal "unixoid" representation too.
      */
     QString OCSYNC_EXPORT pathtoUNC(const QString &str);
+
+    std::filesystem::perms OCSYNC_EXPORT filePermissionsWin(const QString &filename);
+    void OCSYNC_EXPORT setFilePermissionsWin(const QString &filename, const std::filesystem::perms &perms);
 #endif
 
     /**

src/csync/csync_exclude.cpp

@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "config_csync.h"
 #include <qglobal.h>
 
 #ifndef _GNU_SOURCE
@@ -31,6 +31,7 @@
 #include "csync_exclude.h"
 
 #include "common/utility.h"
+#include "common/filesystembase.h"
 #include "../version.h"
 
 #include <QString>
@@ -402,7 +403,7 @@
         while (path.size() > basePath.size()) {
             QFileInfo fi(path);
             if (fi.fileName() != QStringLiteral(".sync-exclude.lst")
-                && (fi.isHidden() || fi.fileName().startsWith(QLatin1Char('.')))) {
+                && (FileSystem::isFileHidden(path) || fi.fileName().startsWith(QLatin1Char('.')))) {
                 return true;
             }
 
@@ -411,9 +412,8 @@
         }
     }
 
-    QFileInfo fi(filePath);
     ItemType type = ItemTypeFile;
-    if (fi.isDir()) {
+    if (OCC::FileSystem::isDir(filePath)) {
         type = ItemTypeDirectory;
     }
 
@@ -437,9 +437,7 @@
     if (filetype == ItemTypeDirectory) {
         const auto basePath = QString(_localPath + path + QLatin1Char('/'));
         const QString absolutePath = basePath + QStringLiteral(".sync-exclude.lst");
-        QFileInfo excludeFileInfo(absolutePath);
-
-        if (excludeFileInfo.isReadable()) {
+        if (FileSystem::isReadable(absolutePath)) {
             addExcludeFilePath(absolutePath);
             reloadExcludeFiles();
         } else {

src/gui/caseclashfilenamedialog.cpp

@@ -19,6 +19,7 @@
 
 #include "account.h"
 #include "folder.h"
+#include "common/filesystembase.h"
 
 #include <QPushButton>
 #include <QDir>
@@ -180,12 +181,12 @@
     while(it.hasNext()) {
         const auto filePath = it.next();
         qCDebug(lcCaseClashConflictFialog) << filePath;
-        QFileInfo fileInfo(filePath);
 
-        if(fileInfo.isDir()) {
+        if (FileSystem::isDir(filePath)) {
             continue;
         }
 
+        QFileInfo fileInfo(filePath);
         const auto currentFileName = fileInfo.fileName();
         if (currentFileName.compare(conflictFileName, Qt::CaseInsensitive) == 0 &&
                 currentFileName != conflictFileName) {