return to preprocessing deferred functions by default

lib/puppet/defaults.rb

@@ -2100,14 +2100,16 @@ def self.initialize_default_settings!(settings)
         what is being done.",
     },
     :preprocess_deferred => {
-      :default => false,
+      :default => true,
       :type => :boolean,
       :desc => "Whether Puppet should call deferred functions before applying
         the catalog. If set to `true`, all prerequisites required for the
         deferred function must be satisfied before the Puppet run. If set to
         `false`, deferred functions follow Puppet relationships and
         ordering. In this way, Puppet can install the prerequisites required for a
-        deferred function and call the deferred function in the same run.",
+        deferred function and call the deferred function in the same run.
+        Please note that many functions that return complex datatypes will fail
+        when disabling preprocessing and this option may be removed in the future.",
     },
     :summarize => {
         :default  => false,

spec/integration/application/agent_spec.rb

@@ -206,6 +206,7 @@ def copy_fixtures(sources, dest)
     end
 
     it "applies a deferred function and its prerequisite in the same run" do
+      Puppet[:preprocess_deferred] = false
       catalog_handler = -> (req, res) {
         catalog = compile_to_catalog(deferred_manifest, node)
         res.body = formatter.render(catalog)

spec/integration/application/apply_spec.rb

@@ -721,6 +721,7 @@ def bogus()
     end
 
     it "applies a deferred function and its prerequisite in the same run" do
+      Puppet[:preprocess_deferred] = false
       apply.command_line.args = ['-e', deferred_manifest]
       expect {
         apply.run
@@ -754,6 +755,7 @@ def bogus()
     end
 
     it "evaluates resources before validating the deferred resource" do
+      Puppet[:preprocess_deferred] = false
       manifest = <<~END
         notify { 'runs before file': } ->
         file { '#{deferred_file}':