[Sbcl-bugs] Strange error in eql inside block form

[ಅಕ್ಷಯ ಶ. ಐ. (A. S. <aks...@gm...>]

Hello,
I stumbled onto this strange bug involving block and eql,
----------------------------------------

(BLOCK NIL
  (EQL -0.0d0
     (LET* ((EXPONENT 0))
       (SETF EXPONENT 1)
       (SCALE-FLOAT -0.0d0 (- EXPONENT 1075)))))
=> NIL

(BLOCK NIL
  (EQL -0.0d0
     (LET* ((EXPONENT 1))
       (SETF EXPONENT 1)
       (SCALE-FLOAT -0.0d0 (- EXPONENT 1075)))))
=> T

(PROGN
  (EQL -0.0d0
     (LET* ((EXPONENT 0))
       (SETF EXPONENT 1)
       (SCALE-FLOAT -0.0d0 (- EXPONENT 1075)))))
=> NIL
----------------------------------------

Can someone help me sort this out ? It looks like some transformation
is not consistent.

Thanks!
Akshay