Index: trunk/ippScripts/scripts/magic_process.pl
===================================================================
--- trunk/ippScripts/scripts/magic_process.pl	(revision 20707)
+++ trunk/ippScripts/scripts/magic_process.pl	(revision 20756)
@@ -120,5 +120,8 @@
         @outputs = ("${outroot}.clusters", "${outroot}_hough.fits", "${outroot}.streaks");
 
-        my $diff_id;
+        my $diff_id = $innode->{diff_id};
+        if (!$diff_id) {
+            &my_die("input for node has null diff_id", $magic_id, $node, $PS_EXIT_UNKNOWN_ERROR);
+        }
         my ($image, $mask, $weight) = resolve_inputs($innode);