Typo in set_layer() - NameError: name 'f' is not defined

[claudinecombe]

Please provide all mandatory information!

Describe the bug (mandatory)

I am trying to use rbgroups in the set_layer() function but it throws an error

  File "fitz/fitz.py", line 5189, in set_layer
    if f != set():
NameError: name 'f' is not defined

When looking at the code, f should be replaced by s

        if rbgroups:
            if type(rbgroups) not in (list, tuple):
                raise ValueError("bad type: 'rbgroups'")
            for x in rbgroups:
                if not type(x) in (list, tuple):
                    raise ValueError("bad RBGroup '%s'" % x)
                s = set(x).difference(ocgs)
                if f != set():
                    raise ValueError("bad OCGs in RBGroup: %s" % s)

To Reproduce (mandatory)

Explain the steps to reproduce the behavior, For example, include a minimal code snippet, example files, etc.

        doc = fitz.open()
        xrefs = {}
        xrefs["oc1"] = doc.add_ocg("oc1", on=False)
        xrefs["oc2"] = doc.add_ocg("oc2", on=True)
        xrefs["oc3"] = doc.add_ocg("oc3", on=False)
        xrefs["oc4"] = doc.add_ocg("oc4", on=False)
        doc.set_layer(-1, on=[3], off=[4, 5, 6], rbgroups=[[4, 5, 6]])

[JorjMcKie]

Thank you!
There indeed is a typo in that line. Will be fixed in next version.
That line should read if s != set():

[julian-smith-artifex-com]

Fixed in 1.23.5.