ASSERTION errors in 4.7.0 file qlayoutengine

I created a Qt (qtsdk-2010.04 (ver 4.6.3 I think)) application on my Ubuntu Linux box, it works quite nicely.

Currently I need to port the app to Windows. I am using an instance of XP SP1 running on Sun's VirtulBox, with Visual Studio 2008 installed. I installed the Qt4.7.0 sources and compiled it with VS2008 and there were no issues. I also installed the VS Qt add-in.

After a little work and massage I finally got the project to build, but when I run it I get this error:

Module: 4.7.0
File: global\qglobal.cpp
Line: 2239

ASSERT: "uniformSpacer >= 0 || spacing >= 0" in file e:\qt\4.7.0\include\qtgui\private\../../../src/gui/kernel/qlayoutengine_p.h, line 78

this is the code snippet from the file qlayoutengine_p.h:

77 int effectiveSpacer(int uniformSpacer) const {
78 Q_ASSERT(uniformSpacer >= 0 || spacing >= 0);
79 return (uniformSpacer >= 0) ? uniformSpacer : spacing;
80 }

So I am assuming that my 'QLayoutStruct.spacing' is a value less than 0. Why? I don't know.

Here is a snippet from my app:

contactsLayout = new QVBoxLayout;

contacts[nCONTACT_TYPE] = new contactWidget(nCONTACT_TYPE,this);
contacts[nBILLING_TYPE] = new contactWidget(nBILLING_TYPE,this);
contacts[nSHIPPING_TYPE] = new contactWidget(nSHIPPING_TYPE,this);

tabWidget = new QTabWidget;
--> tabWidget->addTab(contacts[nCONTACT_TYPE], tr("Contact ID")); <-- error occurs at this line of execution
tabWidget->addTab(contacts[nBILLING_TYPE], tr("Billing ID"));
tabWidget->addTab(contacts[nSHIPPING_TYPE], tr("Shipping ID"));

The current parent widget (vendorWidget) and the contactWidget are BOTH derived from the same base class.

I have almost exactly the same arrangement in another class, "employeeWidget" and "emplyeeContact" are also both derived from the same base class as the vendor widgets, and they suffer exactly the same problems.

IF I build the project minus the offending widgets the rest of the code runs as it should.

This is very similar to QTBUG-13652 which was submitted 17/Sep/10.

One last item, I also tried building the app with qmake and the MinGW tools. That version had the same issues.

Any assistance would be greatly appreciated, thank you.

Jon Aldrich

PS: Did I mention this does not happen at all in the Linux environment ;-)

ASSERTION errors in 4.7.0 file qlayoutengine_p.h