[Solved] Why might ItemClipsChildrenToShape fail?

[Asperamanca]

I use the flag QGraphicsItem::ItemClipsChildrenToShape a lot. I now have a situation where the flag simply is ignored, and I don't know why.
Here is what I checked so far, did I miss anything?

• The child I want clipped is indeed an (indirect) child of the item with ItemClipsChildrentoShape set
• The flag is still set right before I start painting
• The shape of the item is correct, and would clip where I want it to be clipped

I stepped through the drawItems code a bit, and noticed I never entered the ifs related to this kind of clipping. It looks a though the flag is considered "false" although I have set it to true, and the flags() return it as true.

I'd post code, but it's multiple files and I would first have to find out what causes the behavior (because a simple example will work as expected). If you have any suggestions about something specific I should post, please let me know.

EDIT:
Solved. I shot my own foot.
All that ItemClipsChildrenToShape does is to set the clipping region of the painter prior to calling paint. If I then replace the clipping e.g. by calling setClipRect, all that is lost.