next.rb in contrast-agent-4.3.0

- old
+ new

@@ -13,11 +13,10 @@
           class Next < Contrast::Agent::Assess::Policy::Propagator::Base
             class << self
               # String has some silly methods like next. Basically, this flips a
               # character in a predictable manner
               def propagate propagation_node, preshift, target
-                properties = Contrast::Agent::Assess::Tracker.properties(target)
-                return unless properties
+                return unless (properties = Contrast::Agent::Assess::Tracker.properties!(target))
 
                 source = find_source(propagation_node.sources[0], preshift)
                 properties.copy_from(source, target, 0, propagation_node.untags)
 
                 # this means the char that was shifted overflowed and created new