added checking on planet unlink

collects/planet/private/cmdline-tool.rkt

@@ -21,6 +21,7 @@ PLANNED FEATURES:
   
   (define erase? (make-parameter #f))
   (define displayer (make-parameter (λ () (show-installed-packages))))
+  (define quiet-unlink? (make-parameter #f))
   
   (define (start raco?)
 
@@ -85,10 +86,12 @@ Install local file <plt-file> into the planet cache as though it had been downlo
         (add-hard-link-cmd owner pkg maj min path))]
      ["unlink" "remove a package development link"
       "\nRemove development link associated with the given package"
+      #:once-each
+      [("-q" "--quiet") "don't signal an error on nonexistent links" (quiet-unlink? #t)]
       #:args (owner pkg maj min)
       (begin
         (verify-package-name pkg)
-        (remove-hard-link-cmd owner pkg maj min))]
+        (remove-hard-link-cmd owner pkg maj min (quiet-unlink?)))]
      ["fetch" "download a package file without installing it"
        "\nDownload the given package file without installing it"
        #:args (owner pkg maj min)
@@ -264,10 +267,12 @@ This command does not unpack or install the named .plt file."
         (fail "Invalid major/minor version"))
       (add-hard-link ownerstr pkgstr maj min path)))
   
-  (define (remove-hard-link-cmd ownerstr pkgstr majstr minstr)
+  (define (remove-hard-link-cmd ownerstr pkgstr majstr minstr quiet?)
     (let* ([maj (read-from-string majstr)]
            [min (read-from-string minstr)])
-      (remove-hard-link ownerstr pkgstr maj min)))
+      (unless (and (integer? maj) (integer? min) (> maj 0) (>= min 0))
+        (fail "Invalid major/minor version"))
+      (remove-hard-link ownerstr pkgstr maj min quiet?)))
       
   (define (get-download-url ownerstr pkgstr majstr minstr)
     (let ([fps (params->full-pkg-spec ownerstr pkgstr majstr minstr)])

collects/planet/private/planet-shared.rkt

@@ -197,7 +197,7 @@ Various common pieces of code that both the client and server need to access
                           original-table))])
         (save-hard-link-table new-table))))
   
-  ;; filter-link-table! : (row -> boolean) -> void
+  ;; filter-link-table! : (row -> boolean) (row -> any/c) -> void
   ;; removes all rows from the hard link table that don't match the given predicate.
   ;; also updates auxiliary datastructures that might have dangling pointers to
   ;; the removed links

collects/planet/util.rkt

@@ -68,7 +68,8 @@
  [add-hard-link 
   (-> string? (and/c string? #rx"[.]plt") natural-number/c natural-number/c path? void?)]
  [remove-hard-link 
-  (-> string? (and/c string? #rx"[.]plt") natural-number/c natural-number/c void?)]
+  (-> string? (and/c string? #rx"[.]plt") natural-number/c natural-number/c boolean?
+      void?)]
  [remove-pkg
   (-> string? (and/c string? #rx"[.]plt") natural-number/c natural-number/c void?)]
  [erase-pkg
@@ -766,12 +767,16 @@
                  (path->string path))))
   (add-hard-link! pkg-name (list owner) maj min path))
 
-;; remove-hard-link : string string num num -> void
+;; remove-hard-link : string string num num boolean -> void
 ;; removes any development association from the given package spec
-(define (remove-hard-link owner pkg-name maj min)
+(define (remove-hard-link owner pkg-name maj min quiet?)
+  (define (matching-link? row)
+    (points-to? row pkg-name (list owner) maj min))
+  (when (and (empty? (filter matching-link? (get-hard-link-table)))
+             (not quiet?))
+    (error "no existing links match the given specification"))
   (filter-link-table!
-   (lambda (row) 
-     (not (points-to? row pkg-name (list owner) maj min)))
+   (lambda (row) (not (matching-link? row)))
    (lambda (row) 
      (let ([p (row->package row)])
        (when p