diff -r b72c6db6890b -r 5dc02b23752f src/corelib/io/qdatastream.h
--- a/src/corelib/io/qdatastream.h	Wed Jun 23 19:07:03 2010 +0300
+++ b/src/corelib/io/qdatastream.h	Tue Jul 06 15:10:48 2010 +0300
@@ -84,10 +84,11 @@
         Qt_4_3 = 9,
         Qt_4_4 = 10,
         Qt_4_5 = 11,
-        Qt_4_6 = 12
-#if QT_VERSION >= 0x040700
+        Qt_4_6 = 12,
+        Qt_4_7 = Qt_4_6
+#if QT_VERSION >= 0x040800
 #error Add the datastream version for this Qt version
-        Qt_4_7 = Qt_4_6
+        Qt_4_8 = Qt_4_7
 #endif
     };
 
@@ -242,6 +243,7 @@
     l.clear();
     quint32 c;
     s >> c;
+    l.reserve(c);
     for(quint32 i = 0; i < c; ++i)
     {
         T t;