Qmake does not creat .vcproj file correctly if QMAKESPEC directory contains space

Qmake doesn't correctly create a .vcproj file when QMAKESPEC is set to a directory which contains spaces in the path.

Here are steps to reproduce:

1 – Prepare/open a Qt command prompt for compilation.
2 – Set QMAKESPEC to a directory which contains spaces. E.g.:
set QMAKESPEC=C:/dir with spaces/win32-msvc2008
(Ensure that the correct mkspec files are in this directory)
3 - Run "qmake –tp vc" on your .pro.
4 – Launch Visual Studio and select File | Open Project/Solution and load the newly created .vcproj.
5 – Attempt to build the project.

Notice the following error:

1>moc: Too many input files specified ...

This only appears to happen when a .vcproj file is generated from qmake.

Building via qmake, nmake seems to work fine with the spaces.

A simple workaround for this problem is to open the project Properties within Visual Studio and locate the Additional include directories in Configuration Propterties | C/C++ | General and enclose the mkspec path in double quotes.