[Sbcl-devel] Reading single floats bug

[Cedric St-J. <ced...@gm...>]

There is a problem with the reader for a structure containing a single-float:

(defstruct foo
   (x 0.0 :type single-float))

(read-from-string "((#1=#S(foo :x 2.7158911)))")

On SBCL 1.0.14, Ubuntu AMD64, with (optimize debug safety), this
causes a Memory Fault. The system punts in the circularity treatment.
If I remove the #1=, the example runs fine (though if I remember
correctly, something *still* got corrupted in my larger program,
leading to the death of SBCL without any warning)

The problem is dependent on this particular floating-point value. It
appears to be a valid single-float. If I print readably (make-foo :x
2.7158911), I get the string above, minus the #1= and some
parentheses...

Thanks.

Cédric