2 files changed, 24 insertions, 5 deletions
diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 70ee708b61..80ee7b2287 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -68,7 +68,6 @@
 #include <QtCore/QMutex>
 #include <QtCore/QMutexLocker>
 #include <QtCore/QUuid>
-#include <QtCore/QRegularExpression>
 #include <QtCore/QTemporaryFile>
 #include <QtCore/private/qsystemlibrary_p.h>
 
@@ -1135,12 +1134,32 @@ void QWindowsNativeFileDialogBase::setLabelText(QFileDialogOptions::DialogLabel
     }
 }
 
+static bool isHexRange(const QString& s, int start, int end)
+{
+    for (;start < end; ++start) {
+        QChar ch = s.at(start);
+        if (!(ch.isDigit()
+              || (ch >= QLatin1Char('a') && ch <= QLatin1Char('f'))
+              || (ch >= QLatin1Char('A') && ch <= QLatin1Char('F'))))
+            return false;
+    }
+    return true;
+}
+
 static inline bool isClsid(const QString &s)
 {
     // detect "374DE290-123F-4565-9164-39C4925E467B".
-   static const QRegularExpression pattern(QLatin1String("\\A[0-9A-Fa-f]{8}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{4}-[0-9A-Fa-f]{12}\\z"));
-   Q_ASSERT(pattern.isValid());
-   return pattern.match(s).hasMatch();
+    const QChar dash(QLatin1Char('-'));
+    return s.size() == 36
+            && isHexRange(s, 0, 8)
+            && s.at(8) == dash
+            && isHexRange(s, 9, 13)
+            && s.at(13) == dash
+            && isHexRange(s, 14, 18)
+            && s.at(18) == dash
+            && isHexRange(s, 19, 23)
+            && s.at(23) == dash
+            && isHexRange(s, 24, 36);
 }
 
 void QWindowsNativeFileDialogBase::selectFile(const QString &fileName) const
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index ada124b5af..038ee5cd62 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -2558,7 +2558,7 @@ void QWindowsWindow::setCustomMargins(const QMargins &newCustomMargins)
         newFrame.moveTo(topLeft);
         qCDebug(lcQpaWindows) << __FUNCTION__ << oldCustomMargins << "->" << newCustomMargins
             << currentFrameGeometry << "->" << newFrame;
-        SetWindowPos(m_data.hwnd, 0, newFrame.x(), newFrame.y(), newFrame.width(), newFrame.height(), SWP_NOZORDER | SWP_FRAMECHANGED);
+        SetWindowPos(m_data.hwnd, 0, newFrame.x(), newFrame.y(), newFrame.width(), newFrame.height(), SWP_NOZORDER | SWP_FRAMECHANGED | SWP_NOACTIVATE);
     }
 }