Commenting out a function corrupts folding icon place

Folding a function is a usable feature of QtCreator. A folding icon is present right next to the function definition in cpp file. To reproduce the problem, suppose a file like:

void func1()
{
//some implementation
}

void func2()
{
//some implementation
}

void func3()
{
//some implementation
}

Now if you comment out the func1 and your file looks like:
//void func1()
//

[Fold icon appears here on left side]
void func2()
{
//some implementation
}
[no fold icons with this function]
void func3()
{
//some implementation
}