Problematic type declaration in sb-gmp::gmp-intexp

[ari pro]

A type declaration added to sb-gmp in https://github.com/sfrank/sb-gmp/commit/9dc3b852413191f0f6cfd25af04b82d3f09ebc92 and then introduced to SBCL in commit 69f90713f12d00ede7ec1bde098ea94a7a72f03a causes sb-gmp::gmp-intexp to signal a type-error when it is called with a base of type ratio and a negative integral exponent.

One way of fixing this is removing the type declaration.

Here is a demonstration with SBCL 2.3.2:

* (require 'sb-gmp) ;=> ("SB-GMP")
* sb-gmp:*gmp-version* ;=> "6.2.1"
* sb-gmp:*gmp-features* ;=> (:SB-GMP-5.1 :SB-GMP-5.0 :SB-GMP)
* (setf sb-gmp:*gmp-diasbled* T) ;=> T
* (expt 113/355 -1) ;=> 355/113
* (setf sb-gmp:*gmp-disabled* NIL) ;=> NIL
* (expt 113/355 -1) ;=>
debugger invoked on a TYPE-ERROR @225715EC in thread
#<THREAD "main thread" RUNNING {1001420003}>:
  The value
    113/355
  is not of type
    INTEGER

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
  0: [ABORT] Exit debugger, returning to top level.

(SB-GMP::GMP-INTEXP 113/355 -1)
   source: (THE INTEGER (GMP-INTEXP BASE (- POWER)))