caching in QDir in 4.7 is broken

the caching in QDir in 4.7 is broken compared to 4.6.

Attached code prints in qt4.6 something along the lines of:
(".", "..", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")
process finished 5
(".", "..", "foo", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")
(".", "..", "foo", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")

as expected, the file "foo" shows up in both the old and the new QDir's directory listings after created.

With qt4.7, I get the following output:

(".", "..", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")
process finished 5
(".", "..", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")
(".", "..", "foo", "main.cpp", "main.o", "Makefile", "qdirtest", "qdirtest.pro")

The file "foo" only shows up in the 'new' QDir's file listings.