I tried to run a fairly simple list of commands:

weight := k -> if(k = 2, 1/2, 1)

sum(weight(m+2), m = 0 .. 0)

the expected result should be 1/2 - which is weight(2). But Maple returns 1 for some reason.

Is this a bug in Maple or did a make a mistake in my expressions?

Many thanks in advance