webshot generates warning message if v

[warnes]

When webshot is called with the cliprect parameter set to "viewport" it generates the warning message:
Warning: 'length(x) = 4 > 1' in coercion to 'logical(1)'.

Example

webshot::webshot("http://r-project.org", cliprect = "viewport")

This appears to be generated from these lines in mapshot:

webshot/R/webshot.R

Lines 191 to 204 in e5df3d0

	cliprect <- lapply(cliprect, function(x) {
	if (is.character(x)) {
	if (x == "viewport") {
	x <- c(0, 0, vwidth, vheight)
	} else {
	stop("Invalid value for cliprect: ", x)
	}
	} else {
	if (!is.numeric(x) || length(x) != 4) {
	stop("'cliprect' must be a 4-element numeric vector or a list of such vectors")
	}
	}
	x
	})

A simple solution would be to check for cliprect=="viewport" earlier in the function.