RESTART-CASE without clauses signals a STYLE-WARNING

[Jan Moringen]

Compiling RESTART-CASE forms without clauses such as

  (restart-case 1)

causes a STYLE-WARNING for an unused variable to be signaled.

I expected this code to either compile without signaling any warnings or to compile/fail to compile with a more specific warning/error. The Hyperspec seems to allow RESTART-CASE without clauses.

sbcl --version:
SBCL 1.1.3

uname -a:
Linux ferberit 3.5.0-23-generic #35-Ubuntu SMP Thu Jan 24 13:05:29 UTC 2013 i686 i686 i686 GNU/Linux

*FEATURES*:
(:QUICKLISP :SB-BSD-SOCKETS-ADDRINFO :ASDF2 :ASDF :ASDF-UNICODE
 :ALIEN-CALLBACKS :ANSI-CL :C-STACK-IS-CONTROL-STACK :COMMON-LISP
 :COMPARE-AND-SWAP-VOPS :CYCLE-COUNTER :ELF :GENCGC :IEEE-FLOATING-POINT
 :INLINE-CONSTANTS :LARGEFILE :LINKAGE-TABLE :LINUX :LITTLE-ENDIAN
 :MEMORY-BARRIER-VOPS :MULTIPLY-HIGH-VOPS :OS-PROVIDES-BLKSIZE-T
 :OS-PROVIDES-DLADDR :OS-PROVIDES-DLOPEN :OS-PROVIDES-GETPROTOBY-R
 :OS-PROVIDES-POLL :OS-PROVIDES-PUTWC :OS-PROVIDES-SUSECONDS-T
 :RAW-INSTANCE-INIT-VOPS :SB-CORE-COMPRESSION :SB-DOC :SB-EVAL :SB-FUTEX
 :SB-LDB :SB-PACKAGE-LOCKS :SB-SOURCE-LOCATIONS :SB-TEST :SB-THREAD :SB-UNICODE
 :SBCL :STACK-ALLOCATABLE-CLOSURES :STACK-ALLOCATABLE-FIXED-OBJECTS
 :STACK-ALLOCATABLE-LISTS :STACK-ALLOCATABLE-VECTORS
 :STACK-GROWS-DOWNWARD-NOT-UPWARD :UNIX :UNWIND-TO-FRAME-AND-CALL-VOP :X86)

[Stas Boukarev (stassats)]

commit d8c48b14b87d355b1e02f814d9bb8236847bc4de
Author: Stas Boukarev <email address hidden>
Date: Sun Feb 3 13:38:29 2013 +0400

    restart-case: Spurious unused variable warnings.

    restart-case without any restart clauses used to signal an unused
    variable warning, add ignorable declaration.