Added support for symlinks and junction points on Windows

Since ntfs symlinks (not .lnk files) can use
relative paths to targets, support for relative links
needed to be added.
Directory junctions can also be used to mount another
filesystem directly into an existing folder.
Such junctions in that case use the volume id of the
target volume for the link path. Therefor this commit
also includes an implementation for resolving volume ids.

To be independent of existing directories in test code
i added a function to create own junction points.

Reviewed-by: Joao
Task-number: QTBUG-9009, QTBUG-7036

1 files changed, 58 insertions, 0 deletions

diff --git a/tests/shared/filesystem.h b/tests/shared/filesystem.h
index 2d46c0d494..cc1781eb46 100644
--- a/tests/shared/filesystem.h
+++ b/tests/shared/filesystem.h
@@ -48,6 +48,11 @@
 #include <QDir>
 #include <QFile>
 
+#if defined(Q_OS_WIN) && !defined(Q_OS_WINCE)
+# define IO_REPARSE_TAG_MOUNT_POINT       (0xA0000003L)
+# define REPARSE_MOUNTPOINT_HEADER_SIZE   8
+#endif
+
 struct FileSystem
 {
     ~FileSystem()
@@ -86,6 +91,59 @@ struct FileSystem
         }
         return false;
     }
+#if defined(Q_OS_WIN) && !defined(Q_OS_WINCE)
+    static void createNtfsJunction(QString target, QString linkName)
+    {
+        typedef struct {
+            DWORD   ReparseTag;
+            DWORD   ReparseDataLength;
+            WORD    Reserved;
+            WORD    ReparseTargetLength;
+            WORD    ReparseTargetMaximumLength;
+            WORD    Reserved1;
+            WCHAR   ReparseTarget[1];
+        } REPARSE_MOUNTPOINT_DATA_BUFFER, *PREPARSE_MOUNTPOINT_DATA_BUFFER;
+
+        char    reparseBuffer[MAX_PATH*3];
+        HANDLE  hFile;
+        DWORD   returnedLength;
+        wchar_t fileSystem[MAX_PATH] = L"";
+        PREPARSE_MOUNTPOINT_DATA_BUFFER reparseInfo = (PREPARSE_MOUNTPOINT_DATA_BUFFER) reparseBuffer;
+
+        QFileInfo junctionInfo(linkName);
+        linkName = QDir::toNativeSeparators(junctionInfo.absoluteFilePath());
+
+        GetVolumeInformationW( linkName.left(3).utf16(), NULL, 0, NULL, NULL, NULL,
+                               fileSystem, sizeof(fileSystem)/sizeof(WCHAR));
+        if(QString().fromWCharArray(fileSystem) != "NTFS")
+            QSKIP("This seems not to be an NTFS volume. Junctions are not allowed.",SkipSingle);
+
+        if (!target.startsWith("\\??\\") && !target.startsWith("\\\\?\\")) {
+            QFileInfo targetInfo(target);
+            target = QDir::toNativeSeparators(targetInfo.absoluteFilePath());
+            target.prepend("\\??\\");
+            if(target.endsWith('\\') && target.at(target.length()-2) != ':')
+                target.chop(1);
+        }
+        QDir().mkdir(linkName);
+        hFile = CreateFileW( linkName.utf16(), GENERIC_WRITE, 0, NULL, OPEN_EXISTING,
+                             FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, NULL );
+        QVERIFY(hFile != INVALID_HANDLE_VALUE );
+
+        memset( reparseInfo, 0, sizeof( *reparseInfo ));
+        reparseInfo->ReparseTag = IO_REPARSE_TAG_MOUNT_POINT;
+        reparseInfo->ReparseTargetLength = target.size() * sizeof(wchar_t);
+        reparseInfo->ReparseTargetMaximumLength = reparseInfo->ReparseTargetLength + sizeof(wchar_t);
+        target.toWCharArray(reparseInfo->ReparseTarget);
+        reparseInfo->ReparseDataLength = reparseInfo->ReparseTargetLength + 12;
+
+        bool ioc = DeviceIoControl(hFile, FSCTL_SET_REPARSE_POINT, reparseInfo,
+                                 reparseInfo->ReparseDataLength + REPARSE_MOUNTPOINT_HEADER_SIZE,
+                                 NULL, 0, &returnedLength, NULL);
+        CloseHandle( hFile );
+        QVERIFY(ioc);
+    }
+#endif
 
 private:
     QDir currentDir;