fix NTFS mount points

NTFS mount points are not treated as symlinks, because they might
not have a link target.
This is the case when a volume is mounted as a single mount point
without a drive letter.
This patch fixes building Qt in an NTFS mount point.

Task-number: QTBUG-20431
Change-Id: Ie2e15212e1a7ca7fa0067b7ca8857e243e42c21a
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@nokia.com>

3 files changed, 24 insertions, 12 deletions

diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index 7e43684..d807d06 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -796,9 +796,10 @@ static bool tryFindFallback(const QFileSystemEntry &fname, QFileSystemMetaData &
     int errorCode = GetLastError();
     if (errorCode == ERROR_ACCESS_DENIED || errorCode == ERROR_SHARING_VIOLATION) {
         WIN32_FIND_DATA findData;
-        if (getFindData(fname.nativeFilePath(), findData)
+        const QString nativeFilePath = fname.nativeFilePath();
+        if (getFindData(nativeFilePath, findData)
             && findData.dwFileAttributes != INVALID_FILE_ATTRIBUTES) {
-            data.fillFromFindData(findData, true, fname.isDriveRoot());
+            data.fillFromFindData(findData, true, fname.isDriveRoot(), nativeFilePath);
             filledData = true;
         }
     }
@@ -879,8 +880,9 @@ bool QFileSystemEngine::fillMetaData(const QFileSystemEntry &entry, QFileSystemM
         data.knownFlagsMask |= QFileSystemMetaData::LinkType;
         if (data.fileAttribute_ & FILE_ATTRIBUTE_REPARSE_POINT) {
             WIN32_FIND_DATA findData;
-            if (getFindData(fname.nativeFilePath(), findData))
-                data.fillFromFindData(findData, true);
+            const QString nativeFilePath = fname.nativeFilePath();
+            if (getFindData(nativeFilePath, findData))
+                data.fillFromFindData(findData, true, false, nativeFilePath);
         }
     }
     data.knownFlagsMask |= what;
diff --git a/src/corelib/io/qfilesystemiterator_win.cpp b/src/corelib/io/qfilesystemiterator_win.cpp
index 1f5cf35..030ef21 100644
--- a/src/corelib/io/qfilesystemiterator_win.cpp
+++ b/src/corelib/io/qfilesystemiterator_win.cpp
@@ -138,7 +138,7 @@ bool QFileSystemIterator::advance(QFileSystemEntry &fileEntry, QFileSystemMetaDa
         fileEntry = QFileSystemEntry(dirPath + fileName);
         metaData = QFileSystemMetaData();
         if (!fileName.endsWith(QLatin1String(".lnk"))) {
-            metaData.fillFromFindData(findData, true);
+            metaData.fillFromFindData(findData, true, false, fileEntry.nativeFilePath());
         }
         return true;
     }
diff --git a/src/corelib/io/qfilesystemmetadata_p.h b/src/corelib/io/qfilesystemmetadata_p.h
index 7ee080e..f6b5a99 100644
--- a/src/corelib/io/qfilesystemmetadata_p.h
+++ b/src/corelib/io/qfilesystemmetadata_p.h
@@ -234,7 +234,7 @@ public:
 
 #if defined(Q_OS_WIN)
     inline void fillFromFileAttribute(DWORD fileAttribute, bool isDriveRoot = false);
-    inline void fillFromFindData(WIN32_FIND_DATA &findData, bool setLinkType = false, bool isDriveRoot = false);
+    inline void fillFromFindData(WIN32_FIND_DATA &findData, bool setLinkType = false, bool isDriveRoot = false, const QString &nativeFullFilePath = QString());
     inline void fillFromFindInfo(BY_HANDLE_FILE_INFORMATION &fileInfo);
 #endif
 private:
@@ -350,7 +350,7 @@ inline void QFileSystemMetaData::fillFromFileAttribute(DWORD fileAttribute,bool
     knownFlagsMask |= FileType | DirectoryType | HiddenAttribute | ExistsAttribute;
 }
 
-inline void QFileSystemMetaData::fillFromFindData(WIN32_FIND_DATA &findData, bool setLinkType, bool isDriveRoot)
+inline void QFileSystemMetaData::fillFromFindData(WIN32_FIND_DATA &findData, bool setLinkType, bool isDriveRoot, const QString &nativeFullFilePath)
 {
     fillFromFileAttribute(findData.dwFileAttributes, isDriveRoot);
     creationTime_ = findData.ftCreationTime;
@@ -368,13 +368,23 @@ inline void QFileSystemMetaData::fillFromFindData(WIN32_FIND_DATA &findData, boo
         knownFlagsMask |=  LinkType;
         entryFlags &= ~LinkType;
 #if !defined(Q_OS_WINCE)
-        if ((fileAttribute_ & FILE_ATTRIBUTE_REPARSE_POINT)
-            && (findData.dwReserved0 == IO_REPARSE_TAG_SYMLINK
-                || findData.dwReserved0 == IO_REPARSE_TAG_MOUNT_POINT)) {
-            entryFlags |= LinkType;
+        if (fileAttribute_ & FILE_ATTRIBUTE_REPARSE_POINT) {
+            if (findData.dwReserved0 == IO_REPARSE_TAG_SYMLINK) {
+                entryFlags |= LinkType;
+            } else if (findData.dwReserved0 == IO_REPARSE_TAG_MOUNT_POINT) {
+                // Junctions and mount points are implemented as NTFS reparse points.
+                // But mount points cannot be treated as symlinks because they might
+                // not have a link target.
+                wchar_t buf[50];
+                QString path = nativeFullFilePath;
+                if (!path.endsWith(QLatin1Char('\\')))
+                    path.append(QLatin1Char('\\'));
+                BOOL isMountPoint = GetVolumeNameForVolumeMountPoint(reinterpret_cast<const wchar_t*>(path.utf16()), buf, sizeof(buf) / sizeof(wchar_t));
+                if (!isMountPoint)
+                    entryFlags |= LinkType;
+            }
         }
 #endif
-
     }
 }