large file support for Windows CE

Seeking in files above 0x80000000 failed on Windows CE.
SetFilePointer was used in the 32 bit version. That means, seeking only
worked for positions <= LONG_MAX (which is 0x80000000 - 1).

Task-number: 255242
Reviewed-by: mauricek

1 files changed, 19 insertions, 16 deletions

diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index 618566a..5365ff5 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -588,21 +588,23 @@ qint64 QFSFileEnginePrivate::nativePos() const
     if (fileHandle == INVALID_HANDLE_VALUE)
         return 0;
 
-#if !defined(QT_NO_LIBRARY)
+#if !defined(QT_NO_LIBRARY) && !defined(Q_OS_WINCE)
     QFSFileEnginePrivate::resolveLibs();
     if (!ptrSetFilePointerEx) {
 #endif
-        DWORD newFilePointer = SetFilePointer(fileHandle, 0, NULL, FILE_CURRENT);
-        if (newFilePointer == 0xFFFFFFFF) {
+        LARGE_INTEGER filepos;
+        filepos.HighPart = 0;
+        DWORD newFilePointer = SetFilePointer(fileHandle, 0, &filepos.HighPart, FILE_CURRENT);
+        if (newFilePointer == 0xFFFFFFFF && GetLastError() != NO_ERROR) {
             thatQ->setError(QFile::UnspecifiedError, qt_error_string());
             return 0;
         }
 
-        // Note: returns <4GB; does not work with large files. This is the
-        // case for MOC, UIC, qmake and other bootstrapped tools, and for
-        // Win9x/ME.
-        return qint64(newFilePointer);
-#if !defined(QT_NO_LIBRARY)
+        // Note: This is the case for MOC, UIC, qmake and other
+        //       bootstrapped tools, and for Windows CE.
+        filepos.LowPart = newFilePointer;
+        return filepos.QuadPart;
+#if !defined(QT_NO_LIBRARY) && !defined(Q_OS_WINCE)
     }
 
     // This approach supports large files.
@@ -631,21 +633,22 @@ bool QFSFileEnginePrivate::nativeSeek(qint64 pos)
         return seekFdFh(pos);
     }
 
-#if !defined(QT_NO_LIBRARY)
+#if !defined(QT_NO_LIBRARY) && !defined(Q_OS_WINCE)
     QFSFileEnginePrivate::resolveLibs();
     if (!ptrSetFilePointerEx) {
 #endif
-        LONG seekToPos = LONG(pos); // <- lossy
-        DWORD newFilePointer = SetFilePointer(fileHandle, seekToPos, NULL, FILE_BEGIN);
-        if (newFilePointer == 0xFFFFFFFF) {
-            thatQ->setError(QFile::UnspecifiedError, qt_error_string());
+        DWORD newFilePointer;
+        LARGE_INTEGER *li = reinterpret_cast<LARGE_INTEGER*>(&pos);
+        newFilePointer = SetFilePointer(fileHandle, li->LowPart, &li->HighPart, FILE_BEGIN);
+        if (newFilePointer == 0xFFFFFFFF && GetLastError() != NO_ERROR) {
+            thatQ->setError(QFile::PositionError, qt_error_string());
             return false;
         }
 
-        // Note: does not work with large files. This is the case for MOC,
-        // UIC, qmake and other bootstrapped tools, and for Win9x/ME.
+        // Note: This is the case for MOC, UIC, qmake and other
+        //       bootstrapped tools, and for Windows CE.
         return true;
-#if !defined(QT_NO_LIBRARY)
+#if !defined(QT_NO_LIBRARY) && !defined(Q_OS_WINCE)
     }
 
     // This approach supports large files.