Support frozen_string_literal in lib/**/*.rb (#26561).

Contributed by Pavel Rosický. git-svn-id: http://svn.redmine.org/redmine/trunk@17988 e93f8b46-1217-0410-a6f0-8f06a7374b81
2025-11-02 19:36:00 +01:00 · 2019-03-17 16:36:34 +00:00
parent bd5977d97e
commit 30e341db69
40 changed files with 99 additions and 98 deletions
--- a/lib/plugins/acts_as_activity_provider/init.rb
+++ b/lib/plugins/acts_as_activity_provider/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require File.dirname(__FILE__) + '/lib/acts_as_activity_provider'
 ActiveRecord::Base.send(:include, Redmine::Acts::ActivityProvider)
--- a/lib/plugins/acts_as_activity_provider/lib/acts_as_activity_provider.rb
+++ b/lib/plugins/acts_as_activity_provider/lib/acts_as_activity_provider.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/plugins/acts_as_attachable/init.rb
+++ b/lib/plugins/acts_as_attachable/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require File.dirname(__FILE__) + '/lib/acts_as_attachable'
 ActiveRecord::Base.send(:include, Redmine::Acts::Attachable)
--- a/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
+++ b/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/plugins/acts_as_customizable/init.rb
+++ b/lib/plugins/acts_as_customizable/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require File.dirname(__FILE__) + '/lib/acts_as_customizable'
 ActiveRecord::Base.send(:include, Redmine::Acts::Customizable)
--- a/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb
+++ b/lib/plugins/acts_as_customizable/lib/acts_as_customizable.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/plugins/acts_as_event/init.rb
+++ b/lib/plugins/acts_as_event/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require File.dirname(__FILE__) + '/lib/acts_as_event'
 ActiveRecord::Base.send(:include, Redmine::Acts::Event)
--- a/lib/plugins/acts_as_event/lib/acts_as_event.rb
+++ b/lib/plugins/acts_as_event/lib/acts_as_event.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/plugins/acts_as_searchable/init.rb
+++ b/lib/plugins/acts_as_searchable/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require File.dirname(__FILE__) + '/lib/acts_as_searchable'
 ActiveRecord::Base.send(:include, Redmine::Acts::Searchable)
--- a/lib/plugins/acts_as_searchable/lib/acts_as_searchable.rb
+++ b/lib/plugins/acts_as_searchable/lib/acts_as_searchable.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/plugins/acts_as_tree/Rakefile
+++ b/lib/plugins/acts_as_tree/Rakefile
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require 'rake'
 require 'rake/testtask'
--- a/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb
+++ b/lib/plugins/acts_as_tree/lib/active_record/acts/tree.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 module ActiveRecord
  module Acts
--- a/lib/plugins/acts_as_tree/test/acts_as_tree_test.rb
+++ b/lib/plugins/acts_as_tree/test/acts_as_tree_test.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require 'test/unit'

--- a/lib/plugins/acts_as_watchable/init.rb
+++ b/lib/plugins/acts_as_watchable/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Include hook code here
 require File.dirname(__FILE__) + '/lib/acts_as_watchable'
--- a/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb
+++ b/lib/plugins/acts_as_watchable/lib/acts_as_watchable.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # ActsAsWatchable
 module Redmine
--- a/lib/plugins/gravatar/init.rb
+++ b/lib/plugins/gravatar/init.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 require 'gravatar'
 ActionView::Base.send :include, GravatarHelper::PublicMethods
--- a/lib/plugins/open_id_authentication/lib/open_id_authentication.rb
+++ b/lib/plugins/open_id_authentication/lib/open_id_authentication.rb
@@ -89,7 +89,7 @@ module OpenIdAuthentication
    # dodge XRIs -- TODO: validate, don't just skip.
    unless ['=', '@', '+', '$', '!', '('].include?(identifier.at(0))
      # does it begin with http?  if not, add it.
-      identifier = "http://#{identifier}" unless identifier =~ /^http/i
+      identifier = +"http://#{identifier}" unless identifier =~ /^http/i

      # strip any fragments
      identifier.gsub!(/\#(.*)$/, '')
--- a/lib/redmine/field_format.rb
+++ b/lib/redmine/field_format.rb
@@ -185,7 +185,7 @@ module Redmine

      def parse_keyword(custom_field, keyword, &block)
        separator = Regexp.escape ","
-        keyword = keyword.to_s
+        keyword = keyword.dup.to_s

        if custom_field.multiple?
          values = []
--- a/lib/redmine/helpers/diff.rb
+++ b/lib/redmine/helpers/diff.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -46,7 +46,7 @@ module Redmine
          add_at = nil
          add_to = nil
          del_at = nil
-          deleted = ""
+          deleted = +""
          diff.each do |change|
            pos = change[1]
            if change[0] == "+"
--- a/lib/redmine/helpers/gantt.rb
+++ b/lib/redmine/helpers/gantt.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -76,8 +76,8 @@ module Redmine
        end
        @date_from = Date.civil(@year_from, @month_from, 1)
        @date_to = (@date_from >> @months) - 1
-        @subjects = ''
-        @lines = ''
+        @subjects = +''
+        @lines = +''
        @number_of_rows = nil
        @truncated = false
        if options.has_key?(:max_rows)
@@ -198,8 +198,8 @@ module Redmine
                   :indent_increment => 20, :render => :subject,
                   :format => :html}.merge(options)
        indent = options[:indent] || 4
-        @subjects = '' unless options[:only] == :lines
-        @lines = '' unless options[:only] == :subjects
+        @subjects = +'' unless options[:only] == :lines
+        @lines = +'' unless options[:only] == :subjects
        @number_of_rows = 0
        begin
          Project.project_tree(projects) do |project, level|
@@ -652,7 +652,7 @@ module Redmine
        case object
        when Issue
          issue = object
-          css_classes = ''
+          css_classes = +''
          css_classes << ' issue-overdue' if issue.overdue?
          css_classes << ' issue-behind-schedule' if issue.behind_schedule?
          css_classes << ' icon icon-issue' unless Setting.gravatar_enabled? && issue.assigned_to
@@ -663,7 +663,7 @@ module Redmine
            css_classes << ' behind-start-date' if progress_date < self.date_from
            css_classes << ' over-end-date' if progress_date > self.date_to
          end
-          s = "".html_safe
+          s = (+"").html_safe
          if issue.assigned_to.present?
            assigned_string = l(:field_assigned_to) + ": " + issue.assigned_to.name
            s << view.avatar(issue.assigned_to,
@@ -676,7 +676,7 @@ module Redmine
          view.content_tag(:span, s, :class => css_classes).html_safe
        when Version
          version = object
-          html_class = ""
+          html_class = +""
          html_class << 'icon icon-package '
          html_class << (version.behind_schedule? ? 'version-behind-schedule' : '') << " "
          html_class << (version.overdue? ? 'version-overdue' : '')
@@ -691,7 +691,7 @@ module Redmine
          view.content_tag(:span, s, :class => html_class).html_safe
        when Project
          project = object
-          html_class = ""
+          html_class = +""
          html_class << 'icon icon-projects '
          html_class << (project.overdue? ? 'project-overdue' : '')
          s = view.link_to_project(project).html_safe
@@ -727,7 +727,7 @@ module Redmine
        end
        if has_children
          content = view.content_tag(:span, nil, :class => :expander) + content
-          tag_options[:class] << ' open'
+          tag_options[:class] += ' open'
        else
          if params[:indent]
            params = params.dup
@@ -735,7 +735,7 @@ module Redmine
          end
        end
        style = "position: absolute;top:#{params[:top]}px;left:#{params[:indent]}px;"
-        style << "width:#{params[:subject_width] - params[:indent]}px;" if params[:subject_width]
+        style += "width:#{params[:subject_width] - params[:indent]}px;" if params[:subject_width]
        tag_options[:style] = style
        output = view.content_tag(:div, content, tag_options)
        @subjects << output
@@ -774,7 +774,7 @@ module Redmine
      end

      def html_task(params, coords, markers, label, object)
-        output = ''
+        output = +''
        data_options = {}
        data_options[:collapse_expand] = "#{object.class}-#{object.id}".downcase if object

@@ -792,7 +792,7 @@ module Redmine
        # Renders the task bar, with progress and late
        if coords[:bar_start] && coords[:bar_end]
          width = coords[:bar_end] - coords[:bar_start] - 2
-          style = ""
+          style = +""
          style << "top:#{params[:top]}px;"
          style << "left:#{coords[:bar_start]}px;"
          style << "width:#{width}px;"
@@ -812,7 +812,7 @@ module Redmine
          output << view.content_tag(:div, '&nbsp;'.html_safe, content_opt)
          if coords[:bar_late_end]
            width = coords[:bar_late_end] - coords[:bar_start] - 2
-            style = ""
+            style = +""
            style << "top:#{params[:top]}px;"
            style << "left:#{coords[:bar_start]}px;"
            style << "width:#{width}px;"
@@ -823,7 +823,7 @@ module Redmine
          end
          if coords[:bar_progress_end]
            width = coords[:bar_progress_end] - coords[:bar_start] - 2
-            style = ""
+            style = +""
            style << "top:#{params[:top]}px;"
            style << "left:#{coords[:bar_start]}px;"
            style << "width:#{width}px;"
@@ -839,7 +839,7 @@ module Redmine
        # Renders the markers
        if markers
          if coords[:start]
-            style = ""
+            style = +""
            style << "top:#{params[:top]}px;"
            style << "left:#{coords[:start]}px;"
            style << "width:15px;"
@@ -849,7 +849,7 @@ module Redmine
                                       :data => data_options)
          end
          if coords[:end]
-            style = ""
+            style = +""
            style << "top:#{params[:top]}px;"
            style << "left:#{coords[:end] + params[:zoom]}px;"
            style << "width:15px;"
@@ -861,7 +861,7 @@ module Redmine
        end
        # Renders the label on the right
        if label
-          style = ""
+          style = +""
          style << "top:#{params[:top]}px;"
          style << "left:#{(coords[:bar_end] || 0) + 8}px;"
          style << "width:15px;"
@@ -876,7 +876,7 @@ module Redmine
                               view.render_issue_tooltip(object).html_safe,
                               :class => "tip")
          s += view.content_tag(:input, nil, :type => 'checkbox', :name => 'ids[]', :value => object.id, :style => 'display:none;', :class => 'toggle-selection')
-          style = ""
+          style = +""
          style << "position: absolute;"
          style << "top:#{params[:top]}px;"
          style << "left:#{coords[:bar_start]}px;"
--- a/lib/redmine/info.rb
+++ b/lib/redmine/info.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 module Redmine
  module Info
@@ -9,7 +9,7 @@ module Redmine
      def versioned_name; "#{app_name} #{Redmine::VERSION}" end

      def environment
-        s = "Environment:\n"
+        s = +"Environment:\n"
        s << [
          ["Redmine version", Redmine::VERSION],
          ["Ruby version", "#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL} (#{RUBY_RELEASE_DATE}) [#{RUBY_PLATFORM}]"],
--- a/lib/redmine/pagination.rb
+++ b/lib/redmine/pagination.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -159,7 +159,7 @@ module Redmine
        per_page_links = false if count.nil?
        page_param = paginator.page_param

-        html = '<ul class="pages">'
+        html = +'<ul class="pages">'

        if paginator.multiple_pages?
          # \xc2\xab(utf-8) = &#171;
--- a/lib/redmine/scm/adapters/abstract_adapter.rb
+++ b/lib/redmine/scm/adapters/abstract_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -214,7 +214,7 @@ module Redmine
            path = Redmine::Configuration['scm_stderr_log_file'].presence
            path ||= Rails.root.join("log/#{Rails.env}.scm.stderr.log").to_s
            if File.exists?(path)
-              if File.file?(path) && File.writable?(path) 
+              if File.file?(path) && File.writable?(path)
                writable = true
              else
                logger.warn("SCM log file (#{path}) is not writable")
@@ -276,8 +276,9 @@ module Redmine
        end

        def scm_iconv(to, from, str)
-          return nil if str.nil?
+          return if str.nil?
          return str if to == from && str.encoding.to_s == from
+          str = str.dup
          str.force_encoding(from)
          begin
            str.encode(to)
--- a/lib/redmine/scm/adapters/bazaar_adapter.rb
+++ b/lib/redmine/scm/adapters/bazaar_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -154,7 +154,7 @@ module Redmine
                  parsing = $1
                elsif line =~ /^  (.*)$/
                  if parsing == 'message'
-                    revision.message << "#{$1}\n"
+                    revision.message += "#{$1}\n"
                  else
                    if $1 =~ /^(.*)\s+(\S+)$/
                      path_locale = $1.strip
--- a/lib/redmine/scm/adapters/cvs_adapter.rb
+++ b/lib/redmine/scm/adapters/cvs_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # redMine - project management software
 # Copyright (C) 2006-2007  Jean-Philippe Lang
@@ -93,7 +93,7 @@ module Redmine
        def entries(path=nil, identifier=nil, options={})
          logger.debug "<cvs> entries '#{path}' with identifier '#{identifier}'"
          path_locale = scm_iconv(@path_encoding, 'UTF-8', path)
-          path_locale.force_encoding("ASCII-8BIT")
+          path_locale = path_locale.dup.force_encoding("ASCII-8BIT")
          entries = Entries.new
          cmd_args = %w|-q rls -e|
          cmd_args << "-D" << time_to_cvstime_rlog(identifier) if identifier
@@ -161,7 +161,7 @@ module Redmine
          cmd_args << path_with_project_utf8
          scm_cmd(*cmd_args) do |io|
            state      = "entry_start"
-            commit_log = String.new
+            commit_log = ""
            revision   = nil
            date       = nil
            author     = nil
@@ -171,7 +171,7 @@ module Redmine
            branch_map = nil
            io.each_line() do |line|
              if state != "revision" && /^#{ENDLOG}/ =~ line
-                commit_log = String.new
+                commit_log = ""
                revision   = nil
                state      = "entry_start"
              end
@@ -186,7 +186,7 @@ module Redmine
                elsif /^symbolic names:/ =~ line
                  state = "symbolic" #unless entry.nil?
                elsif /^#{STARTLOG}/ =~ line
-                  commit_log = String.new
+                  commit_log = ""
                  state      = "revision"
                end
                next
@@ -230,7 +230,7 @@ module Redmine
                           }]
                         })
                  end
-                  commit_log = String.new
+                  commit_log = ""
                  revision   = nil
                  if /^#{ENDLOG}/ =~ line
                    state = "entry_start"
@@ -261,7 +261,7 @@ module Redmine
                  #                  version.line_minus = 0
                  #                end
                else
-                  commit_log << line unless line =~ /^\*\*\* empty log message \*\*\*/
+                  commit_log += line unless line =~ /^\*\*\* empty log message \*\*\*/
                end
              end
            end
--- a/lib/redmine/scm/adapters/filesystem_adapter.rb
+++ b/lib/redmine/scm/adapters/filesystem_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/scm/adapters/git_adapter.rb
+++ b/lib/redmine/scm/adapters/git_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -203,7 +203,7 @@ module Redmine
          cmd_args << "--" << scm_iconv(@path_encoding, 'UTF-8', path) if path && !path.empty?
          revisions = []
          if identifier_from || identifier_to
-            revisions << ""
+            revisions << +""
            revisions[0] << "#{identifier_from}.." if identifier_from
            revisions[0] << "#{identifier_to}" if identifier_to
          else
@@ -261,7 +261,7 @@ module Redmine
                end
              elsif (parsing_descr == 0) && line.chomp.to_s == ""
                parsing_descr = 1
-                changeset[:description] = ""
+                changeset[:description] = +""
              elsif (parsing_descr == 1 || parsing_descr == 2) \
                  && line =~ /^:\d+\s+\d+\s+[0-9a-f.]+\s+[0-9a-f.]+\s+(\w)\t(.+)$/
                parsing_descr = 2
--- a/lib/redmine/scm/adapters/mercurial_adapter.rb
+++ b/lib/redmine/scm/adapters/mercurial_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/scm/adapters/subversion_adapter.rb
+++ b/lib/redmine/scm/adapters/subversion_adapter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -61,7 +61,7 @@ module Redmine

        # Get info about the svn repository
        def info
-          cmd = "#{self.class.sq_bin} info --xml #{target}"
+          cmd = +"#{self.class.sq_bin} info --xml #{target}"
          cmd << credentials_string
          info = nil
          shellout(cmd) do |io|
@@ -91,7 +91,7 @@ module Redmine
          path ||= ''
          identifier = (identifier and identifier.to_i > 0) ? identifier.to_i : "HEAD"
          entries = Entries.new
-          cmd = "#{self.class.sq_bin} list --xml #{target(path)}@#{identifier}"
+          cmd = +"#{self.class.sq_bin} list --xml #{target(path)}@#{identifier}"
          cmd << credentials_string
          shellout(cmd) do |io|
            output = io.read.force_encoding('UTF-8')
@@ -130,7 +130,7 @@ module Redmine
          return nil unless self.class.client_version_above?([1, 5, 0])

          identifier = (identifier and identifier.to_i > 0) ? identifier.to_i : "HEAD"
-          cmd = "#{self.class.sq_bin} proplist --verbose --xml #{target(path)}@#{identifier}"
+          cmd = +"#{self.class.sq_bin} proplist --verbose --xml #{target(path)}@#{identifier}"
          cmd << credentials_string
          properties = {}
          shellout(cmd) do |io|
@@ -152,7 +152,7 @@ module Redmine
          identifier_from = (identifier_from && identifier_from.to_i > 0) ? identifier_from.to_i : "HEAD"
          identifier_to = (identifier_to && identifier_to.to_i > 0) ? identifier_to.to_i : 1
          revisions = Revisions.new
-          cmd = "#{self.class.sq_bin} log --xml -r #{identifier_from}:#{identifier_to}"
+          cmd = +"#{self.class.sq_bin} log --xml -r #{identifier_from}:#{identifier_to}"
          cmd << credentials_string
          cmd << " --verbose " if  options[:with_paths]
          cmd << " --limit #{options[:limit].to_i}" if options[:limit]
@@ -192,7 +192,7 @@ module Redmine

          identifier_to = (identifier_to and identifier_to.to_i > 0) ? identifier_to.to_i : (identifier_from.to_i - 1)

-          cmd = "#{self.class.sq_bin} diff -r "
+          cmd = +"#{self.class.sq_bin} diff -r "
          cmd << "#{identifier_to}:"
          cmd << "#{identifier_from}"
          cmd << " #{target(path)}@#{identifier_from}"
@@ -209,7 +209,7 @@ module Redmine

        def cat(path, identifier=nil)
          identifier = (identifier and identifier.to_i > 0) ? identifier.to_i : "HEAD"
-          cmd = "#{self.class.sq_bin} cat #{target(path)}@#{identifier}"
+          cmd = +"#{self.class.sq_bin} cat #{target(path)}@#{identifier}"
          cmd << credentials_string
          cat = nil
          shellout(cmd) do |io|
@@ -222,7 +222,7 @@ module Redmine

        def annotate(path, identifier=nil)
          identifier = (identifier and identifier.to_i > 0) ? identifier.to_i : "HEAD"
-          cmd = "#{self.class.sq_bin} blame #{target(path)}@#{identifier}"
+          cmd = +"#{self.class.sq_bin} blame #{target(path)}@#{identifier}"
          cmd << credentials_string
          blame = Annotate.new
          shellout(cmd) do |io|
@@ -244,7 +244,7 @@ module Redmine
        private

        def credentials_string
-          str = ''
+          str = +''
          str << " --username #{shell_quote(@login)}" unless @login.blank?
          str << " --password #{shell_quote(@password)}" unless @login.blank? || @password.blank?
          str << " --no-auth-cache --non-interactive"
--- a/lib/redmine/unified_diff.rb
+++ b/lib/redmine/unified_diff.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -274,7 +274,7 @@ module Redmine

    def line_to_html_raw(line, offsets)
      if offsets
-        s = ''
+        s = +''
        unless offsets.first == 0
          s << CGI.escapeHTML(line[0..offsets.first-1])
        end
--- a/lib/redmine/wiki_formatting.rb
+++ b/lib/redmine/wiki_formatting.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/html_parser.rb
+++ b/lib/redmine/wiki_formatting/html_parser.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/macros.rb
+++ b/lib/redmine/wiki_formatting/macros.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/markdown/formatter.rb
+++ b/lib/redmine/wiki_formatting/markdown/formatter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -83,7 +83,7 @@ module Redmine
        end

        def extract_sections(index)
-          sections = ['', '', '']
+          sections = [+'', +'', +'']
          offset = 0
          i = 0
          l = 1
--- a/lib/redmine/wiki_formatting/markdown/helper.rb
+++ b/lib/redmine/wiki_formatting/markdown/helper.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/markdown/html_parser.rb
+++ b/lib/redmine/wiki_formatting/markdown/html_parser.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/textile/formatter.rb
+++ b/lib/redmine/wiki_formatting/textile/formatter.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
@@ -65,9 +65,9 @@ module Redmine
          @pre_list = []
          text = self.dup
          rip_offtags text, false, false
-          before = ''
-          s = ''
-          after = ''
+          before = +''
+          s = +''
+          after = +''
          i = 0
          l = 1
          started = false
--- a/lib/redmine/wiki_formatting/textile/helper.rb
+++ b/lib/redmine/wiki_formatting/textile/helper.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/textile/html_parser.rb
+++ b/lib/redmine/wiki_formatting/textile/html_parser.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 # Redmine - project management software
 # Copyright (C) 2006-2017  Jean-Philippe Lang
--- a/lib/redmine/wiki_formatting/textile/redcloth3.rb
+++ b/lib/redmine/wiki_formatting/textile/redcloth3.rb
@@ -1,4 +1,4 @@
-# frozen_string_literal: false
+# frozen_string_literal: true

 #                                vim:ts=4:sw=4:
 # = RedCloth - Textile and Markdown Hybrid for Ruby
@@ -467,7 +467,7 @@ class RedCloth3 < String
    # Parses Textile attribute lists and builds an HTML attribute string
    def pba( text_in, element = "" )
        
-        return '' unless text_in
+        return +'' unless text_in

        style = []
        text = text_in.dup
@@ -505,7 +505,7 @@ class RedCloth3 < String

        id = id.starts_with?('wiki-id-') ? id : "wiki-id-#{id}" if id

-        atts = ''
+        atts = +''
        atts << " style=\"#{ style.join }\"" unless style.empty?
        atts << " class=\"#{ cls }\"" unless cls.to_s.empty?
        atts << " lang=\"#{ lang }\"" if lang
@@ -586,9 +586,9 @@ class RedCloth3 < String
                        depth << tl
                        atts = pba( atts )
                        atts = shelve( atts ) if atts
-                        lines[line_id] = "\t<#{ lT(tl) }l#{ atts }>\n\t<li>#{ content }"
+                        lines[line_id] = +"\t<#{ lT(tl) }l#{ atts }>\n\t<li>#{ content }"
                    else
-                        lines[line_id] = "\t\t<li>#{ content }"
+                        lines[line_id] = +"\t\t<li>#{ content }"
                    end
                    last_line = line_id

@@ -611,7 +611,7 @@ class RedCloth3 < String
    def block_textile_quotes( text )
      text.gsub!( QUOTES_RE ) do |match|
        lines = match.split( /\n/ )
-        quotes = ''
+        quotes = +''
        indent = 0
        lines.each do |line|
          line =~ QUOTES_CONTENT_RE 
@@ -639,7 +639,7 @@ class RedCloth3 < String
        text.gsub!( CODE_RE ) do |m|
            before,lang,code,after = $~[1..4]
            lang = " lang=\"#{ lang }\"" if lang
-            rip_offtags( "#{ before }<code#{ lang }>#{ code }</code>#{ after }", false )
+            rip_offtags( +"#{ before }<code#{ lang }>#{ code }</code>#{ after }", false )
        end
    end

@@ -851,7 +851,7 @@ class RedCloth3 < String
              post = ")"+post # add closing parenth to post
            end
            atts = pba( atts )
-            atts = " href=\"#{ htmlesc url }#{ slash }\"#{ atts }"
+            atts = +" href=\"#{ htmlesc url }#{ slash }\"#{ atts }"
            atts << " title=\"#{ htmlesc title }\"" if title
            atts = shelve( atts ) if atts
            
@@ -962,7 +962,7 @@ class RedCloth3 < String
            stln,algn,atts,url,title,href,href_a1,href_a2 = $~[1..8]
            htmlesc title
            atts = pba( atts )
-            atts = " src=\"#{ htmlesc url.dup }\"#{ atts }"
+            atts = +" src=\"#{ htmlesc url.dup }\"#{ atts }"
            atts << " title=\"#{ title }\"" if title
            atts << " alt=\"#{ title }\"" 
            # size = @getimagesize($url);
@@ -973,7 +973,7 @@ class RedCloth3 < String

            next m unless uri_with_safe_scheme?(url)

-            out = ''
+            out = +''
            out << "<a#{ shelve( " href=\"#{ href }\"" ) }>" if href
            out << "<img#{ shelve( atts ) } />"
            out << "</a>#{ href_a1 }#{ href_a2 }" if href
@@ -1096,25 +1096,25 @@ class RedCloth3 < String
                    if codepre - used_offtags.length > 0
                        htmlesc( line, :NoQuotes ) if escape_line
                        @pre_list.last << line
-                        line = ""
+                        line = +""
                    else
                        ### htmlesc is disabled between CODE tags which will be parsed with highlighter
                        ### Regexp in formatter.rb is : /<code\s+class="(\w+)">\s?(.+)/m
                        ### NB: some changes were made not to use $N variables, because we use "match"
                        ###   and it breaks following lines
                        htmlesc( aftertag, :NoQuotes ) if aftertag && escape_aftertag && !first.match(/<code\s+class="(\w+)">/)
-                        line = "<redpre##{ @pre_list.length }>"
+                        line = +"<redpre##{ @pre_list.length }>"
                        first.match(/<#{ OFFTAGS }([^>]*)>/)
                        tag = $1
                        $2.to_s.match(/(class\=("[^"]+"|'[^']+'))/i)
                        tag << " #{$1}" if $1 && tag == 'code'
-                        @pre_list << "<#{ tag }>#{ aftertag }"
+                        @pre_list << +"<#{ tag }>#{ aftertag }"
                    end
                elsif $1 and codepre > 0
                    if codepre - used_offtags.length > 0
                        htmlesc( line, :NoQuotes ) if escape_line
                        @pre_list.last << line
-                        line = ""
+                        line = +""
                    end
                    codepre -= 1 unless codepre.zero?
                    used_offtags = {} if codepre.zero?