Take the addressbook example project.

Create a directory named Test inside the addressbook directory.

Open the addressbook.pro file and add these statements:
INCLUDEPATH+= $$quote($$PWD/.) # Project directory
INCLUDEPATH+= $$quote($$PWD/Test) # Test directory in project directory

In Visual Studio 2008, choose Qt->Open Qt Project File and open the addressbook.pro file. This builds the VC project.

In the Solution Explorer window, right-click the addressbook icon and choose Properties.

In the C++/General section, inspect the Additional Include Directories setting.

With Qt VS Addin 1.1.9, this setting includes "." as an include directory.

With Qt VS Addin 1.1.10, this setting does not include "." as an include directory.