density with weights missing values

Dear R users,

This works as expected:

? plot(density(c(1,2, 3, 4, 5, NA), na.rm=TRUE))

This raises an error

? plot(density(c(1,2, 3, 4, 5, NA), na.rm=TRUE, weights=c(1, 1, 1, 1, 1, 1)))
? plot(density(c(1,2, 3, 4, 5, NA), na.rm=TRUE, weights=c(1, 1, 1, 1, 1, NA)))

This seems to work (it triggers a warning that the weights don?t add up to 1, which makes sense*):

? plot(density(c(1,2, 3, 4, 5, NA), na.rm=TRUE, weights=c(1, 1, 1, 1, 1)))

Questions

? But shouldn?t the na.rm filter also filter the corresponding weights?
? Extra question: In case the na.rm filter is changed to filter the weights, the check for sum(weights) == 1 might trigger false positive warnings since the weights might not add up to 1 anymore

Best wishes,

Matthias