do.call, browser and traceback

A problem that I've encountered when using do.call a lot is very large
stack traces, eg:

f <- function(x) stop()
do.call(error, mtcars)
traceback()
f <- function(x) browser()
do.call(f, mtcars)

I have hacked together my own version of traceback to fix this by
limiting the length of each line to 80 characters, but I can't see any
way to do something similar for browser.  Any suggestions?

Thanks,

Hadley