glXGetFBConfigs() return value

[Tomas Carnecky]

It returns 'GLXFBConfig *', but 'GLXFBConfig' is typedef'd to a pointer
to __GLXFBConfigRec, so glXGetFBConfigs() returns a list of pointers to
__GLXFBConfigRec. But, with my binary nvidia driver, the list doesn't
contain actual pointers, but GLXFBConfigID's (0xa1 isn't a valid
pointer, and I have a visual with GLX_FBCONFIG_ID=0xa1).
Now if I get the list from glXGetFBConfigs(), am I allowed to make a
local copy of a GLXFBConfig and keep it even after I XFree() the list? A
small piece of code will explain better what I want to do:

GLXFBConfig *list = glXGetFBConfigs(...);
GLXFBConfig copy = list[0];
XFree(list);
glXGetFBConfigAttrib(.., copy, ..);

Will that work on all drivers, and not just the binary nvidia?

thanks
tom