#p"\\\\" gives SB-KERNEL:BOUNDING-INDICES-BAD-ERROR

[Willem Broekema]

0] #p"\\\\"

debugger invoked on a SB-KERNEL:BOUNDING-INDICES-BAD-ERROR:
  The bounding indices 3 and 2 are bad for a sequence of length 2.
See also:
  The ANSI Standard, Glossary entry for "bounding index designator"
  The ANSI Standard, writeup for Issue SUBSEQ-OUT-OF-BOUNDS:IS-AN-ERROR

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

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

(SB-INT:SEQUENCE-BOUNDING-INDICES-BAD-ERROR "\\\\" 3 2)
0[2] backtrace

0: (SB-INT:SEQUENCE-BOUNDING-INDICES-BAD-ERROR "\\\\" 3 2)
1: (SB-KERNEL:%FIND-POSITION
    #\\
    "\\\\"
    NIL
    3
    2
    #<FUNCTION IDENTITY>
    #<FUNCTION EQL>)
2: (SB-IMPL::EXTRACT-DEVICE "\\\\" 0 2)
3: (SB-IMPL::PARSE-WIN32-NAMESTRING #<unavailable argument> 0 2)
4: (SB-IMPL::%PARSE-NAMESTRING
    "\\\\"
    NIL
    #P"c:\\Willem\\lisp\\slime\\contrib\\"
    0
    NIL
    NIL)
5: (PARSE-NAMESTRING
    "\\\\"
    NIL
    #P"c:\\Willem\\lisp\\slime\\contrib\\"
    :START
    0
    :END
    NIL
    :JUNK-ALLOWED
    NIL)
6: (SB-IMPL::%READ-PRESERVING-WHITESPACE
    #<SYNONYM-STREAM :SYMBOL *TERMINAL-IO* {223D3A99}>
    NIL
    (NIL)
    T)

[Alastair Bridgewater (alastair-bridgewater)]

Confirmed on 1.0.32.28 Win32.

The second branch of the COND in EXTRACT-DEVICE (src;code;win32-pathname.lisp) calls POSITION passing (+ START 3) as the start but only verifies (>= END (+ START 2)), causing an error for the specific case of (extract-device "\\\\").

Adding a test that there are at least three characters in the range to the AND in the test for the branch in question is sufficient to cause the function to indicate that there is no device component.

After this change, we have:

* (describe #p"\\\\")

#P"\\"
  [structure-object]

Slots with :INSTANCE allocation:
  HOST = #<SB-IMPL::WIN32-HOST {22423411}>
  DEVICE = NIL
  DIRECTORY = (:ABSOLUTE)
  NAME = NIL
  TYPE = NIL
  VERSION = NIL

, which is presumably correct.

[Alastair Bridgewater (alastair-bridgewater)]

Fixed in 1.0.33.2.