[Reworded question :)] How to set minimum (but still expandable) size for column?

[Moschops]

I have a QTreeView with four columns. Sometimes, on the Solaris build, the first column shrinks to the width of the little tree-navigation buttons (those little buttons next to a row that expand the row to show its children). Just on the Solaris version.

I call setStretchLastSection(false) after setting the model, as advised elsewhere, but it doesn't seem to make a difference.

@ ui->projectExplorerTreeView->setModel(model.data());
ui->projectExplorerTreeView->header()->setStretchLastSection(false);@

I'd rather not have to manually force the first column to have a minimum size, as it's very conceivable that the user might want to shrink the column size - it's just very bad for it to happen by itself. Are there any other settings I could fiddle with that anyone knows of?

[Moschops]

Okay, no response to this question; how about changing it a bit. How can I set a minimum size for the first column, such that the user can resize it manually but not below a certain width? Hopefully, if I can do this, whatever is causing the Solaris version to shrink it to almost zero will also obey the minimum size.

I see functions for setting the size, but I don't see one for setting a minimum allowed size.

Edit: I have a headerMinimumSectionSize set in the header's properties, but this seems to be ignored sometimes on the Solaris version; from reading the documentation, I can't tell if the headerMinimumSectonSize is meant to be an absolute, always on minimum value no matter what, or if it's something that could be ignored.