diff -r 56cd8111b7f7 -r 41300fa6a67c src/corelib/tools/qstring.h
--- a/src/corelib/tools/qstring.h	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/corelib/tools/qstring.h	Tue Feb 02 00:43:10 2010 +0200
@@ -631,6 +631,7 @@
     friend class QCharRef;
     friend class QTextCodec;
     friend class QStringRef;
+    friend struct QAbstractConcatenable;
     friend inline bool qStringComparisonHelper(const QString &s1, const char *s2);
     friend inline bool qStringComparisonHelper(const QStringRef &s1, const char *s2);
 public:
@@ -1064,7 +1065,7 @@
 }
 #endif
 
-#ifndef QT_NO_DATASTREAM
+#if !defined(QT_NO_DATASTREAM) || (defined(QT_BOOTSTRAPPED) && !defined(QT_BUILD_QMAKE))
 Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, const QString &);
 Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QString &);
 #endif