fixes #7764 - add quirks mode to JSON.dump

app/models/lookup_key.rb

@@ -135,7 +135,14 @@ def default_value_before_type_cast
   def value_before_type_cast(val)
     case key_type.to_sym
       when :json, :array
-        val = JSON.dump val
+        begin
+          val = JSON.dump(val)
+        rescue JSON::GeneratorError => error
+          ## http://projects.theforeman.org/issues/9553
+          ## @TODO: remove when upgrading to json >= 1.8
+          logger.debug "Fallback to quirks mode from error: '#{error}'"
+          val = JSON.dump_in_quirks_mode(val)
+        end
       when :yaml, :hash
         val = YAML.dump val
         val.sub!(/\A---\s*$\n/, '')

config/initializers/json.rb

@@ -0,0 +1,24 @@
+require 'json/version'
+module JSON
+  class << self
+    def dump_in_quirks_mode(obj, anIO = nil, limit = nil)
+      if anIO && limit.nil?
+        an_io_obj = anIO.to_io if anIO.respond_to?(:to_io)
+        unless anIO.respond_to?(:write)
+          limit = anIO
+          an_io_obj = nil
+        end
+      end
+      limit ||= 0
+      result = generate(obj, :allow_nan => true, :max_nesting => limit, :quirks_mode => true)
+      if an_io_obj
+        an_io_obj.write result
+        an_io_obj
+      else
+        result
+      end
+    rescue JSON::NestingError
+      raise ArgumentError, "exceed depth limit"
+    end
+  end
+end