[armedbear-devel] Bug in translate-logical-pathname.

[logicmoo at gmail.com]

Has this been fixed in trunk yet?

----- Original Message ----- 
From: "Thomas Russ" <tar at ISI.EDU>
To: <armedbear-devel at common-lisp.net>
Cc: "Thomas Russ" <tar at ISI.EDU>
Sent: Monday, November 16, 2009 12:14 PM
Subject: [armedbear-devel] Bug in translate-logical-pathname.


> There seems to be a bug in TRANSLATE-LOGICAL-PATHNAME when the logical  
> pathname source includes constant elements in addition to wildcards.
> 
> Here is an example that demonstrates the problem:
> 
>  CL-USER(1): (setf (logical-pathname-translations "L")
>            '(("L:NATIVE;**;*.*" "/usr/lisp/abcl/native/**/*.*")))
> 
>  ((#P"L:NATIVE;**;*.*" #P"/usr/lisp/abcl/native/**/*.*"))
> 
> 
>  CL-USER(2): (translate-logical-pathname "L:NATIVE;TEST;FOO.FASL")
> 
>  #P"/usr/lisp/abcl/native/native/test/foo.fasl"
> 
> ;; ERROR.  Should be #P"/usr/lisp/abcl/native/test/foo.fasl"
> ;;
> ;; With :wild-inferiors, the full directory path is copied instead of
> ;; just the part after the matching constant part.  That results in
> ;; the "native" element appearing twice.
> ;;
> 
> The problem seems to be in the file "abcl/src/org/armedbear/lisp/ 
> pathnames.lisp", in the function SYSTEM::TRANSLATE-DIRECTORY-COMPONENTS:
> 
> (defun translate-directory-components (source from to case)
>   (cond ((null to)
>          nil
>          )
>         ((memq (car to) '(:absolute :relative))
>          (cons (car to)
>                (translate-directory-components (cdr source) (cdr  
> from) (cdr to) case))
>          )
>         ((eq (car to) :wild)
>          (if (eq (car from) :wild)
>              ;; Grab the next chunk from SOURCE.
>              (append (casify (car source) case)
>                      (translate-directory-components (cdr source)  
> (cdr from) (cdr to) case))
>              (error "Unsupported case 1: ~S ~S ~S" source from to))
>          )
>         ((eq (car to) :wild-inferiors)
>          ;; Grab the next chunk from SOURCE.
>          (append (casify (car source) case)
>                  (translate-directory-components (cdr source) (cdr  
> from) (cdr to) case))
>          )
>         (t
>          ;; "If the piece in TO-WILDCARD is present and not wild, it  
> is copied
>          ;; into the result."
>          (append (casify (car to) case)
>                  (translate-directory-components source from (cdr to)  
> case))
>          )
>         ))
> 
> The final COND clause ("T") needs to be more sophisticated in what it  
> does.  If there are non-wildcard elements in the FROM, then it will  
> need to eliminate the the common prefix between "source" and "from".   
> In order to be a valid match, it I think it SHOULD be guaranteed that  
> a non-wildcard "from" component is a leading subsequence or equal to  
> "source" -- but I'm not fully familiar with the code, but a quick test  
> seems to indicate that the following modified function covers at least  
> the simpler cases of this issue.  It adds a new clause checking  
> for :WILD-INFERIORS in the FROM slot which performs the current  
> function, and changes the T clause to properly manage the subsequence  
> matching.
> 
> (defun translate-directory-components (source from to case)
>   (cond ((null to)
>          nil
>          )
>         ((memq (car to) '(:absolute :relative))
>          (cons (car to)
>                (translate-directory-components (cdr source) (cdr  
> from) (cdr to) case))
>          )
>         ((eq (car to) :wild)
>          (if (eq (car from) :wild)
>              ;; Grab the next chunk from SOURCE.
>              (append (casify (car source) case)
>                      (translate-directory-components (cdr source)  
> (cdr from) (cdr to) case))
>              (error "Unsupported case 1: ~S ~S ~S" source from to))
>          )
>         ((eq (car to) :wild-inferiors)
>          ;; Grab the next chunk from SOURCE.
>          (append (casify (car source) case)
>                  (translate-directory-components (cdr source) (cdr  
> from) (cdr to) case))
>          )
> ((eq (car from) :wild-inferiors)
>          ;; "If the piece in TO-WILDCARD is present and not wild, and  
> the FROM item
> ;;  doesn't contain any constants, then just copy TO to the result."
>          (append (casify (car to) case)
>                  (translate-directory-components source from (cdr to)  
> case)))
>         (t
>          ;; "If the piece in TO-WILDCARD is present and not wild,  
> then FROM should
>          ;;  be a subsequence of SOURCE.  The common subsequence  
> needs to be removed
>          ;;  in the recursive call.  Special case handling for a full  
> match is
>          ;;  also needed."
>          (let ((pos (mismatch (car source) (car from) :test #'string- 
> equal)))
>            (append (casify (car to) case)
>                    (if (null pos) ;; A full match, pop both source  
> and from
>                      (translate-directory-components  (cdr source)  
> (cdr from) (cdr to) case)
>                      (translate-directory-components (cons (subseq  
> (car source) pos) (cdr source)) (cdr from) (cdr to) case))))
>          )
>         ))
> 
> 
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