(PUP-11841) Fix encoding of empty String

In 2077971 empty string literals where
replaced by a call to `String.new` in preparation for moving to
frozen/immutable strings.

However, as stated in the String#new documentation, when no value is
passed to `#new` the returned string has the 'ASCII-8BIT' encoding
instead of the default one (which is assumed to be 'UTF-8' by Puppet).

This cause regressions in some areas of the code, for example when using
the concat module with exported resource built using epp templates, the
incorrect encoding cause the fragment to be misinterpreted and is base64
encoded.  When collected, the base64 representation of the string is
used instead of the actual value of the string, as reported here:
voxpupuli/puppet-bacula#189

Replace calls to `String.new` with `''.dup` which use the current
encoding.  Do not change the few explicit but redundant occurrences of
`String.new.force_encoding('ASCII-8BIT')` (so that the intent is clearly
visible).  Where appropriate, slightly adjust the code for better
readability.

Author: smortex

lib/puppet/application/doc.rb

@@ -152,7 +152,7 @@ def rdoc
   end
 
   def other
-    text = String.new
+    text = ''.dup
     with_contents = options[:references].length <= 1
     exit_code = 0
     require_relative '../../puppet/util/reference'

lib/puppet/face/config.rb

@@ -82,7 +82,7 @@
     end
 
     when_rendering :console do |to_be_rendered|
-      output = String.new
+      output = ''.dup
       if to_be_rendered.keys.length > 1
         to_be_rendered.keys.sort.each do |setting|
           output << "#{setting} = #{to_be_rendered[setting]}\n"

lib/puppet/face/epp.rb

@@ -367,7 +367,7 @@
   end
 
   def dump_parse(source, filename, options, show_filename = true)
-    output = String.new
+    output = ''.dup
     evaluating_parser = Puppet::Pops::Parser::EvaluatingParser::EvaluatingEppParser.new
     begin
       if options[:validate]
@@ -451,7 +451,7 @@ def render_inline(epp_source, compiler, options)
 
   def render_file(epp_template_name, compiler, options, show_filename, file_nbr)
     template_args = get_values(compiler, options)
-    output = String.new
+    output = ''.dup
     begin
       if show_filename && options[:header]
         output << "\n" unless file_nbr == 1

lib/puppet/face/module/list.rb

@@ -74,7 +74,7 @@
       environment     = result[:environment]
       modules_by_path = result[:modules_by_path]
 
-      output = String.new
+      output = ''.dup
 
       warn_unmet_dependencies(environment)
 
@@ -248,7 +248,7 @@ def list_build_tree(list, ancestors=[], parent=nil, params={})
   # Returns a Hash
   #
   def list_build_node(mod, parent, params)
-    str = String.new
+    str = ''.dup
     str << (mod.forge_name ? mod.forge_name.tr('/', '-') : mod.name)
     str << ' (' + colorize(:cyan, mod.version ? "v#{mod.version}" : '???') + ')'
 

lib/puppet/face/parser.rb

@@ -174,7 +174,7 @@
   end
 
   def dump_parse(source, filename, options, show_filename = true)
-    output = String.new
+    output = ''.dup
     evaluating_parser = Puppet::Pops::Parser::EvaluatingParser.new
     begin
       if options[:validate]

lib/puppet/indirector/facts/facter.rb

@@ -105,7 +105,7 @@ def self.setup_external_search_paths(request)
 
   def find_with_options(request)
     options = request.options
-    options_for_facter = String.new
+    options_for_facter = ''.dup
     options_for_facter += options[:user_query].join(' ')
     options_for_facter += " --config #{options[:config_file]}" if options[:config_file]
     options_for_facter += " --show-legacy" if options[:show_legacy]

lib/puppet/indirector/file_bucket_file/file.rb

@@ -58,7 +58,7 @@ def list(request)
       end
       # Setting hash's default value to [], needed by the following loop
       bucket = Hash.new {[]}
-      msg = String.new
+      msg = ''.dup
       # Get all files with mtime between 'from' and 'to'
       Pathname.new(request.options[:bucket_path]).find { |item|
         if item.file? and item.basename.to_s == "paths"

lib/puppet/indirector/indirection.rb

@@ -81,7 +81,7 @@ def expiration
 
   # Generate the full doc string.
   def doc
-    text = String.new
+    text = ''.dup
 
     text << scrub(@doc) << "\n\n" if @doc
 

lib/puppet/module_tool.rb

@@ -70,7 +70,7 @@ def self.is_module_root?(path)
     # Builds a formatted tree from a list of node hashes containing +:text+
     # and +:dependencies+ keys.
     def self.format_tree(nodes, level = 0)
-      str = String.new
+      str = ''.dup
       nodes.each_with_index do |node, i|
         last_node = nodes.length - 1 == i
         deps = node[:dependencies] || []

lib/puppet/network/formats.rb

@@ -156,7 +156,7 @@ def render(datum)
 
     # Simple hash to table
     if datum.is_a?(Hash) && datum.keys.all? { |x| x.is_a?(String) || x.is_a?(Numeric) }
-      output = String.new
+      output = ''.dup
       column_a = datum.empty? ? 2 : datum.map{ |k,v| k.to_s.length }.max + 2
       datum.sort_by { |k,v| k.to_s } .each do |key, value|
         output << key.to_s.ljust(column_a)
@@ -169,7 +169,7 @@ def render(datum)
 
     # Print one item per line for arrays
     if datum.is_a? Array
-      output = String.new
+      output = ''.dup
       datum.each do |item|
         output << item.to_s
         output << "\n"
@@ -227,7 +227,7 @@ def flatten_array(array)
   end
 
   def construct_output(data)
-    output = String.new
+    output = ''.dup
     data.each do |key, value|
       output << "#{key}=#{value}"
       output << "\n"