entget from another DWG without activating it

[Ahankhah]

Hi everyone,

I wrote an AutoLISP program that extracts a DWG’s contents into the current drawing without opening the file. Since VLA_OBJECTs are limited, I used entget, but AutoCAD crashes with a Fatal Error.

Does anyone know what might be wrong or which part of the code I should fix?
 

(defun MT:GetFileD (title lastPath defaultfile ext flag /)
 (or (= 'STR (type defaultfile)) (setq defaultfile ""))
 (if (= 'STR (type lastPath))
  (setq defaultfile (strcat lastPath "\\" defaultfile))
 )
 (getfiled title defaultfile ext flag)
)

(defun MT:GetEntgetListFromDwg (dwgfilename / doc ss entgetlist)
 (if (setq dwgfilename (findfile dwgfilename))
  (progn
   (setq doc (vla-open (vla-get-Documents (vlax-get-acad-object)) dwgfilename :vlax-false))
   (setq entgetlist '())
   (setq ss (vla-get-ModelSpace doc))
   (vlax-for obj ss
    (setq entgetlist (cons (entget (vlax-vla-object->ename obj)) entgetlist))
   )
   (vlax-release-object ss)
   (setq ss nil)
   (vla-close doc)
   (vlax-release-object doc)
  )
 )
 entgetlist
)

(defun MT:RefineEntgetList (entgetlist / item)
 (foreach item entgetlist
  (setq newitem (vl-remove (assoc -1 item) item))
  (setq newitem (vl-remove (assoc 330 item) newitem))
  (setq newitem (vl-remove (assoc 5 item) newitem))
  (setq entgetlist (subst newitem item entgetlist))
 )
 entgetlist
)

;;;(c:CompareDwgs)
(defun c:CompareDwgs (/ regKey lastPath mainfile revisedfile entlist-main entlist-revised entlist-first entlist-second
                      entlist-both ss ent
                     )
 ;; registry key to store last path
 (setq regKey "HKEY_CURRENT_USER\\Software\\Ahankhah\\CompareDwgs")
 (setq lastPath (vl-registry-read regKey "LastPath"))
 ;; ask user for first file
 (setq mainfile (MT:GetFileD "Select main drawing" lastPath "main.dwg" "dwg" 0))
 ;; if user cancelled, exit gracefully
 (if (not mainfile)
  (progn (princ "\nOperation canceled by user.") (princ))
  ;; else proceed to ask for second file
  (progn
   (setq lastPath (vl-filename-directory mainfile))
   (vl-registry-write regKey "LastPath" lastPath)
   ;; use folder of first file as default for second
   (setq revisedfile (MT:GetFileD "Select revised drawing" lastPath "revised.dwg" "dwg" 0))
   ;; if user cancelled selecting second file, exit gracefully
   (if (not revisedfile)
    (progn (princ "\nOperation canceled by user.") (princ))
    ;; else we have both files — save last path (folder of second) and continue
    (progn
     (setq lastPath (vl-filename-directory revisedfile))
     (vl-registry-write regKey "LastPath" lastPath)
     (setq entlist-main (MT:GetEntgetListFromDwg mainfile))
     (setq entlist-revised (MT:GetEntgetListFromDwg revisedfile))
     (setq entlist-first (MT:RefineEntgetList entlist-main))
     (setq entlist-second (MT:RefineEntgetList entlist-revised))
     (setq entlist-both '())
     (foreach elist entlist-first
      (if (member elist entlist-second)
       (progn
        (setq entlist-first (vl-remove elist entlist-first))
        (setq entlist-second (vl-remove elist entlist-second))
        (setq entlist-both (cons elist entlist-both))
       )
      )
     )
     (princ "\nComparison done. Lists are ready.")
     (foreach elist entlist-both (entmakex elist))
     (foreach elist entlist-first
      (if (assoc 62 elist)
       (setq elist (subst (cons 62 1) (assoc 62 elist) elist))
       (setq elist (append elist (list (cons 62 1))))
      )
      (entmakex elist)
     )
     (foreach elist entlist-second
      (if (assoc 62 elist)
       (setq elist (subst (cons 62 2) (assoc 62 elist) elist))
       (setq elist (append elist (list (cons 62 2))))
      )
      (entmakex elist)
     )
     (princ)
    )                                             ; end else have revisedfile
   )                                              ; end if revisedfile
  )                                               ; end else have mainfile
 )                                                ; end if mainfile
)