SBCL

SB-SEQUENCE: error when iterating lists from end

Bug #1799831 reported by Christophe on 2018-10-24

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	SBCL	Fix Released	Undecided	Unassigned

Bug Description

The code for SB-SEQUENCE:MAKE-LIST-ITERATOR, in the case where one iterates over lists from the end, seems broken. The following code failed:

     (sb-sequence:with-sequence-iterator-functions
         (next stop value _set _index _copy)
         ('(a b c d) :from-end t)
       (loop until (stop) collect (value) do (next)))

... with the following error:

    The value
      (D)
    is not of type
      NUMBER
    when binding SB-KERNEL::X
       [Condition of type TYPE-ERROR]

Tested on SBCL 1.4.0.75.release.1710-6a36da1, the code is still the same on the master branch.

Linux XPS-13-9343 4.4.0-134-generic #160-Ubuntu SMP Wed Aug 15 14:58:00 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

(:QUICKLISP :SB-BSD-SOCKETS-ADDRINFO :ASDF3.3 :ASDF3.2 :ASDF3.1 :ASDF3 :ASDF2
:ASDF :OS-UNIX :NON-BASE-CHARS-EXIST-P :ASDF-UNICODE :64-BIT :64-BIT-REGISTERS
:ALIEN-CALLBACKS :ANSI-CL :ASH-RIGHT-VOPS :C-STACK-IS-CONTROL-STACK
:CALL-SYMBOL :COMMON-LISP :COMPACT-INSTANCE-HEADER :COMPARE-AND-SWAP-VOPS
:COMPLEX-FLOAT-VOPS :CYCLE-COUNTER :ELF :FLOAT-EQL-VOPS
:FP-AND-PC-STANDARD-SAVE :GCC-TLS :GENCGC :IEEE-FLOATING-POINT :IMMOBILE-CODE
:IMMOBILE-SPACE :INLINE-CONSTANTS :INTEGER-EQL-VOP :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 :PACKAGE-LOCAL-NICKNAMES :RAW-INSTANCE-INIT-VOPS
:RAW-SIGNED-WORD :RELOCATABLE-HEAP :SB-CORE-COMPRESSION :SB-DOC :SB-EVAL
:SB-FUTEX :SB-LDB :SB-PACKAGE-LOCKS :SB-SIMD-PACK :SB-SOURCE-LOCATIONS
:SB-THREAD :SB-UNICODE :SB-XREF-FOR-INTERNALS :SBCL
:STACK-ALLOCATABLE-CLOSURES :STACK-ALLOCATABLE-FIXED-OBJECTS
:STACK-ALLOCATABLE-LISTS :STACK-ALLOCATABLE-VECTORS
:STACK-GROWS-DOWNWARD-NOT-UPWARD :SYMBOL-INFO-VOPS :UNBIND-N-VOP
:UNDEFINED-FUN-RESTARTS :UNIX :UNWIND-TO-FRAME-AND-CALL-VOP :X86-64)