bug fix integer overflow in medpolish function

Dear R team

I noticed a bug in the "medpolish" function in the "stats" package.
When I run medpolish(x), with "x" the matrix in the attached .rda file,
I get this rather cryptic error:

"Error in if (converged) break : missing value where TRUE/FALSE needed
In addition: Warning message:
In sum(abs(z), na.rm = na.rm) : integer overflow - use sum(as.numeric(.))"

I traced this down to the line:

newsum <- sum(abs(z), na.rm = na.rm)

I think this "overflow" could be easily fixed by changing this line to:

newsum <- sum(as.numeric(abs(z)), na.rm = na.rm)