Correct logic to prevent duplicate queuing of jobs during discover due to previous change in admin table

Netdisco/Changes

@@ -11,6 +11,8 @@
   [BUG FIXES]
 
   * Respect macsuck_bleed on broken topology detection
+  * Correct logic to prevent duplicate queuing of jobs during discover due
+    to previous change in admin table
 
 2.020001 - 2013-12-08
 

Netdisco/lib/App/Netdisco/Core/Discover.pm

@@ -848,14 +848,21 @@ sub discover_new_neighbors {
           next;
       }
 
-      # could fail if queued job already exists
-      try {
-          schema('netdisco')->resultset('Admin')->create({
-              device => $ip,
+      # Don't queued if job already exists
+      my $is_queued = schema('netdisco')->resultset('Admin')->search(
+          {   device => $ip,
+              action => 'discover',
+              status => { -like => 'queued%' },
+          }
+      )->single;
+      unless ($is_queued) {
+          schema('netdisco')->resultset('Admin')->create(
+              {   device => $ip,
                   action => 'discover',
                   status => 'queued',
-          });
-      };
+              }
+          );
+      }
   }
 }