user/group-information should return #f for unknown users

ashinn · Feb 23, 2024 · 19c7d4f · 19c7d4f
1 parent 56ef426
commit 19c7d4f
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Showing 2 changed files with 9 additions and 8 deletions.
diff --git a/lib/chibi/system.sld b/lib/chibi/system.sld
@@ -17,11 +17,12 @@
    (else
     (export user-information group-information)
     (body
+     (define (safe-car x) (and (pair? x) (car x)))
      (define (user-information user)
-       (car (if (string? user)
-                (getpwnam_r user (make-string 1024))
-                (getpwuid_r user (make-string 1024)))))
+       (safe-car (if (string? user)
+                     (getpwnam_r user (make-string 1024))
+                     (getpwuid_r user (make-string 1024)))))
      (define (group-information group)
-       (car (if (string? group)
-                (getgrnam_r group (make-string 1024))
-                (getgrgid_r group (make-string 1024)))))))))
+       (safe-car (if (string? group)
+                     (getgrnam_r group (make-string 1024))
+                     (getgrgid_r group (make-string 1024)))))))))
diff --git a/lib/chibi/tar.scm b/lib/chibi/tar.scm
@@ -24,9 +24,9 @@
    #u8(0 0 0 0 0 0 0 0 0 0 0 0)))
 
 (define (file-owner-or-nobody uid)
-  (or (user-name (user-information uid)) "nobody"))
+  (or (cond ((user-information uid) => user-name) (else #f)) "nobody"))
 (define (file-group-or-nobody gid)
-  (or (group-name (group-information gid)) "nobody"))
+  (or (cond ((group-information gid) => group-name) (else #f)) "nobody"))
 
 (define (make-tar file mode uid gid size mod-time type . o)
   (let* ((link (if (pair? o) (car o) ""))