3 files changed, 43 insertions, 1 deletions
diff --git a/src/corelib/io/qfsfileengine_p.h b/src/corelib/io/qfsfileengine_p.h
index 3b148e1dbb..98c9463c9d 100644
--- a/src/corelib/io/qfsfileengine_p.h
+++ b/src/corelib/io/qfsfileengine_p.h
@@ -151,6 +151,9 @@ public:
 #ifndef Q_OS_WIN
     bool isSequentialFdFh() const;
 #endif
+#ifdef Q_OS_WIN
+    bool nativeRenameOverwrite(const QString &newName) const;
+#endif
 
     uchar *map(qint64 offset, qint64 size, QFile::MemoryMapFlags flags);
     bool unmap(uchar *ptr);
diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index 7a4f99cc7b..3685a3cde5 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -27,6 +27,8 @@
 #define SECURITY_WIN32
 #include <security.h>
 
+#include <memory>
+
 #ifndef PATH_MAX
 #define PATH_MAX FILENAME_MAX
 #endif
@@ -394,6 +396,36 @@ bool QFSFileEnginePrivate::nativeIsSequential() const
             || (fileType == FILE_TYPE_PIPE);
 }
 
+bool QFSFileEnginePrivate::nativeRenameOverwrite(const QString &newName) const
+{
+    if (fileHandle == INVALID_HANDLE_VALUE)
+        return false;
+    QFileSystemEntry newEntry(newName, QFileSystemEntry::FromInternalPath());
+    const QString newFilePath = newEntry.nativeFilePath();
+    const size_t nameByteLength = newFilePath.length() * sizeof(wchar_t);
+    if (nameByteLength + sizeof(wchar_t) > std::numeric_limits<DWORD>::max())
+        return false;
+
+    constexpr size_t RenameInfoSize = sizeof(FILE_RENAME_INFO);
+    const size_t renameDataSize = RenameInfoSize + nameByteLength + sizeof(wchar_t);
+    QVarLengthArray<char> v(qsizetype(renameDataSize), 0);
+
+    auto *renameInfo = q20::construct_at(reinterpret_cast<FILE_RENAME_INFO *>(v.data()));
+    auto renameInfoRAII = qScopeGuard([&] { std::destroy_at(renameInfo); });
+    renameInfo->ReplaceIfExists = TRUE;
+    renameInfo->RootDirectory = nullptr;
+    renameInfo->FileNameLength = DWORD(nameByteLength);
+    memcpy(renameInfo->FileName, newFilePath.data(), nameByteLength);
+
+    bool res = SetFileInformationByHandle(fileHandle, FileRenameInfo, renameInfo,
+                                          DWORD(renameDataSize));
+#if 0
+    if (!res)
+        qErrnoWarning("QFSFileEnginePrivate::nativeRenameOverwrite failed");
+#endif
+    return res;
+}
+
 bool QFSFileEngine::caseSensitive() const
 {
     return false;
diff --git a/src/corelib/io/qtemporaryfile.cpp b/src/corelib/io/qtemporaryfile.cpp
index a99ad22223..59f52bd082 100644
--- a/src/corelib/io/qtemporaryfile.cpp
+++ b/src/corelib/io/qtemporaryfile.cpp
@@ -184,8 +184,9 @@ static bool createFileFromTemplate(NativeFileHandle &file, QTemporaryFileName &t
         const DWORD shareMode = (flags & QTemporaryFileEngine::Win32NonShared)
                                 ? 0u : (FILE_SHARE_READ | FILE_SHARE_WRITE);
 
+        const DWORD extraAccessFlags = (flags & QTemporaryFileEngine::Win32NonShared) ? DELETE : 0;
         file = CreateFile((const wchar_t *)path.constData(),
-                GENERIC_READ | GENERIC_WRITE,
+                GENERIC_READ | GENERIC_WRITE | extraAccessFlags,
                 shareMode, NULL, CREATE_NEW,
                 FILE_ATTRIBUTE_NORMAL, NULL);
 
@@ -390,6 +391,12 @@ bool QTemporaryFileEngine::renameOverwrite(const QString &newName)
         QFSFileEngine::close();
         return ok;
     }
+#ifdef Q_OS_WIN
+    if (d_func()->nativeRenameOverwrite(newName)) {
+        QFSFileEngine::close();
+        return true;
+    }
+#endif
     QFSFileEngine::close();
     return QFSFileEngine::renameOverwrite(newName);
 }