Bug 276913: Uninitialized value message from CGI.pl line 176

Patch: LpSolit@netscape.net  r=mkanat  a=justdave

webtools/bugzilla/CGI.pl

@@ -173,7 +173,7 @@ sub ValidateBugID {
     FetchOneColumn()
       || ThrowUserError("invalid_bug_id_non_existent", {'bug_id' => $id});
 
-    return if ($field eq "dependson" || $field eq "blocked");
+    return if (defined $field && ($field eq "dependson" || $field eq "blocked"));
     
     return if Bugzilla->user->can_see_bug($id);