deftransform for replace is unsafe
|Reported by:||rtoy||Owned by:||somebody|
Consider this function
(defun bad (s) (declare (simple-string s)) (replace s s :start2 100 :end2 105))
After compiling this,
(bad (copy-seq "1234567890"))
Produces a totally bogus result, filling in the first 4 characters of the resulting string with garbage.
The problem is that the deftransform for replace just calls BIT-BASH-COPY without verifying that the start and end indices make sense for the given string. Note that it also doesn't check to see that end >= start, but this gets handled by BIT-BASH-COPY which gets a negative length and signals an error.