diff --git a/app/controllers/dmsf_controller.rb b/app/controllers/dmsf_controller.rb
index 73182275..c1a39b61 100644
--- a/app/controllers/dmsf_controller.rb
+++ b/app/controllers/dmsf_controller.rb
@@ -378,9 +378,10 @@ class DmsfController < ApplicationController
     zipped_content = DmsfHelper.temp_dir.join(DmsfHelper.temp_filename('dmsf_email_sent_documents.zip'))
 
     File.open(zipped_content, 'wb') do |f|
-      zip_file = File.open(zip.finish, 'rb')
-      while (buffer = zip_file.read(8192))
-        f.write(buffer)
+      File.open(zip.finish, 'rb') do |zip_file|
+        while (buffer = zip_file.read(8192))
+          f.write(buffer)
+        end
       end
     end
 
@@ -402,8 +403,8 @@ class DmsfController < ApplicationController
       :folders => selected_folders,
       :files => selected_files,
       :subject => "#{@project.name} #{l(:label_dmsf_file_plural).downcase}",
-      :from => Setting.plugin_redmine_dmsf['dmsf_documents_email_from'].blank? ?
-        "#{User.current.name} <#{User.current.mail}>" : Setting.plugin_redmine_dmsf['dmsf_documents_email_from'],
+      :from => Setting.plugin_redmine_dmsf['dmsf_documents_email_from'].presence ||
+        "#{User.current.name} <#{User.current.mail}>",
       :reply_to => Setting.plugin_redmine_dmsf['dmsf_documents_email_reply_to']
     }
     render :action => 'email_entries'
@@ -434,7 +435,7 @@ class DmsfController < ApplicationController
   end
 
   def zip_entries(zip, selected_folders, selected_files)
-    member = Member.where(user_id: User.current.id, project_id: @project.id).first
+    member = Member.find_by(user_id: User.current.id, project_id: @project.id)
     selected_folders.each do |selected_folder_id|
       folder = DmsfFolder.visible.find_by(id: selected_folder_id)
       if folder
@@ -684,7 +685,7 @@ class DmsfController < ApplicationController
       @subfolders = DmsfHelper.visible_folders(@subfolders, @project)
     end
 
-    @ajax_upload_size = Setting.plugin_redmine_dmsf['dmsf_max_ajax_upload_filesize'].present? ? Setting.plugin_redmine_dmsf['dmsf_max_ajax_upload_filesize'] : 100
+    @ajax_upload_size = Setting.plugin_redmine_dmsf['dmsf_max_ajax_upload_filesize'].presence || 100
 
     # Trash
     @trash_visible = @folder_manipulation_allowed && @file_manipulation_allowed &&
diff --git a/app/controllers/dmsf_files_controller.rb b/app/controllers/dmsf_files_controller.rb
index b4785365..689eb0ba 100644
--- a/app/controllers/dmsf_files_controller.rb
+++ b/app/controllers/dmsf_files_controller.rb
@@ -57,7 +57,7 @@ class DmsfFilesController < ApplicationController
       access.dmsf_file_revision = @revision
       access.action = DmsfFileRevisionAccess::DownloadAction
       access.save!
-      member = Member.where(user_id: User.current.id, project_id: @file.project.id).first
+      member = Member.find_by(user_id: User.current.id, project_id: @file.project.id)
       if member && !member.dmsf_title_format.nil? && !member.dmsf_title_format.empty?
         title_format = member.dmsf_title_format
       else
diff --git a/app/controllers/dmsf_state_controller.rb b/app/controllers/dmsf_state_controller.rb
index e3551e56..9af7e476 100644
--- a/app/controllers/dmsf_state_controller.rb
+++ b/app/controllers/dmsf_state_controller.rb
@@ -27,7 +27,7 @@ class DmsfStateController < ApplicationController
   before_action :authorize
 
   def user_pref_save
-    member = @project.members.where(user_id: User.current.id).first
+    member = @project.members.find_by(user_id: User.current.id)
     if member
       member.dmsf_mail_notification = params[:email_notify]
       member.dmsf_title_format = params[:title_format]
@@ -49,7 +49,7 @@ class DmsfStateController < ApplicationController
   private
   
   def format_valid?(format)
-    format.blank? || ((format =~ /%(t|d|v|i|r)/) && format.length < 256)
+    format.blank? || ((/%(t|d|v|i|r)/.match?(format)) && format.length < 256)
   end
 
 end
\ No newline at end of file
diff --git a/app/controllers/dmsf_workflows_controller.rb b/app/controllers/dmsf_workflows_controller.rb
index 57001ed3..ad37ab06 100644
--- a/app/controllers/dmsf_workflows_controller.rb
+++ b/app/controllers/dmsf_workflows_controller.rb
@@ -339,7 +339,7 @@ class DmsfWorkflowsController < ApplicationController
       end
       operator = (params[:commit] == l(:dmsf_and)) ? DmsfWorkflowStep::OPERATOR_AND : DmsfWorkflowStep::OPERATOR_OR
       user_ids = User.where(id: params[:user_ids]).ids
-      if user_ids.count > 0
+      if user_ids.any?
         user_ids.each do |user_id|
           ws = DmsfWorkflowStep.new
           ws.dmsf_workflow_id = @dmsf_workflow.id
diff --git a/app/helpers/dmsf_helper.rb b/app/helpers/dmsf_helper.rb
index 0f7ec4e3..a3af0d0c 100644
--- a/app/helpers/dmsf_helper.rb
+++ b/app/helpers/dmsf_helper.rb
@@ -48,11 +48,13 @@ module DmsfHelper
     # get only the filename, not the whole path
     just_filename = File.basename(filename.gsub('\\\\', '/'))
     # replace all non alphanumeric, hyphens or periods with underscore
-    just_filename = just_filename.gsub(/[^\w\.\-]/,'_')
-    unless just_filename =~ %r{^[a-zA-Z0-9_\.\-]*$}
+    just_filename.gsub!(/[^\w\.\-]/, '_')
+    unless %r{^[a-zA-Z0-9_\.\-]*$}.match?(just_filename)
       # keep the extension if any
-      extension = $1 if just_filename =~ %r{(\.[a-zA-Z0-9]+)$}
-      just_filename = Digest::SHA256.hexdigest(just_filename)  << extension
+      if just_filename =~ %r{(\.[a-zA-Z0-9]+)$}
+        extension = $1
+        just_filename = Digest::SHA256.hexdigest(just_filename) << extension
+      end
     end
     just_filename
   end
diff --git a/app/helpers/dmsf_workflows_helper.rb b/app/helpers/dmsf_workflows_helper.rb
index 01509f6c..62ba5fbc 100644
--- a/app/helpers/dmsf_workflows_helper.rb
+++ b/app/helpers/dmsf_workflows_helper.rb
@@ -51,7 +51,7 @@ module DmsfWorkflowsHelper
     options = Array.new
     options << [l(:dmsf_new_step), 0]
     steps.each do |step|
-      options << [step.name.present? ? step.name : step.step.to_s, step.step]
+      options << [step.name.presence || step.step.to_s, step.step]
     end
     options_for_select(options, 0)
   end
diff --git a/app/models/dmsf_file.rb b/app/models/dmsf_file.rb
index e286bec1..eb0cbee0 100644
--- a/app/models/dmsf_file.rb
+++ b/app/models/dmsf_file.rb
@@ -391,7 +391,7 @@ class DmsfFile < ActiveRecord::Base
               next if dmsf_attrs.length == 0 || id_attribute == 0
               next unless results.select{|f| f.id.to_s == id_attribute}.empty?
 
-              dmsf_file = DmsfFile.visible.where(limit_options).where(id: id_attribute).first
+              dmsf_file = DmsfFile.visible.where(limit_options).find_by(id: id_attribute)
 
               if dmsf_file && DmsfFolder.permissions?(dmsf_file.dmsf_folder)
                 if user.allowed_to?(:view_dmsf_files, dmsf_file.project) &&
@@ -417,7 +417,7 @@ class DmsfFile < ActiveRecord::Base
   end
 
   def display_name
-    member = Member.where(user_id: User.current.id, project_id: project_id).first
+    member = Member.find_by(user_id: User.current.id, project_id: project_id)
     if member && !member.dmsf_title_format.nil? && !member.dmsf_title_format.empty?
       title_format = member.dmsf_title_format
     else
diff --git a/app/models/dmsf_folder.rb b/app/models/dmsf_folder.rb
index fe4d5a0c..8d217888 100644
--- a/app/models/dmsf_folder.rb
+++ b/app/models/dmsf_folder.rb
@@ -130,9 +130,9 @@ class DmsfFolder < ActiveRecord::Base
 
   def self.find_by_title(project, folder, title)
     if folder
-      visible.where(project_id: project.id, dmsf_folder_id: nil, title: title).first
+      visible.find_by(project_id: project.id, dmsf_folder_id: nil, title: title)
     else
-      visible.where(project_id: project.id, dmsf_folder_id: folder.id, title: title).first
+      visible.find_by(project_id: project.id, dmsf_folder_id: folder.id, title: title)
     end
   end
 
diff --git a/app/models/dmsf_mailer.rb b/app/models/dmsf_mailer.rb
index cfec0697..33adc322 100644
--- a/app/models/dmsf_mailer.rb
+++ b/app/models/dmsf_mailer.rb
@@ -52,7 +52,7 @@ class DmsfMailer < Mailer
   end
 
   def files_deleted(user, project, files)
-    if user && files.count > 0
+    if user && files.any?
       redmine_headers 'Project' => project.identifier if project
       @files = files
       @project = project
diff --git a/app/validators/dmsf_file_name_validator.rb b/app/validators/dmsf_file_name_validator.rb
index 5996dbc7..7e9b0411 100644
--- a/app/validators/dmsf_file_name_validator.rb
+++ b/app/validators/dmsf_file_name_validator.rb
@@ -22,7 +22,7 @@
 class DmsfFileNameValidator  < ActiveModel::EachValidator
 
   def validate_each(record, attribute, value)
-    unless value =~ /\A[^#{DmsfFolder::INVALID_CHARACTERS}]*\z/
+    unless /\A[^#{DmsfFolder::INVALID_CHARACTERS}]*\z/.match?(value)
       record.errors.add attribute, :error_contains_invalid_character
     end
   end
diff --git a/app/views/dmsf/_dmsf_rows.erb b/app/views/dmsf/_dmsf_rows.erb
index 45540ab1..bdfd2420 100644
--- a/app/views/dmsf/_dmsf_rows.erb
+++ b/app/views/dmsf/_dmsf_rows.erb
@@ -23,7 +23,7 @@
 <% parent = @folder ? @folder : @project %>
 <% DmsfHelper.all_children_sorted(parent, @pos, @idnt).each do |obj, position| %>
     <% classes = "dmsf_tree idnt-#{@idnt} hascontextmenu" %>
-    <% if obj.is_a?(DmsfFolder) && ((obj.dmsf_folders.visible.count > 0) || (obj.dmsf_files.visible.count > 0) || (obj.dmsf_links.visible.count > 0)) %>
+    <% if obj.is_a?(DmsfFolder) && ((obj.dmsf_folders.visible.any?) || (obj.dmsf_files.visible.any?) || (obj.dmsf_links.visible.any?)) %>
         <% classes += ' idnt dmsf_collapsed dmsf-not-loaded' %>
         <% id = "id='#{obj.id}span'".html_safe %>
         <% onclick = "onclick=\"dmsfToggle('#{obj.id}','#{obj.id}span','#{escape_javascript(expand_folder_dmsf_path)}')\"" %>
diff --git a/app/views/settings/_dmsf_settings.html.erb b/app/views/settings/_dmsf_settings.html.erb
index 2e5aaa5c..501c8750 100644
--- a/app/views/settings/_dmsf_settings.html.erb
+++ b/app/views/settings/_dmsf_settings.html.erb
@@ -78,11 +78,11 @@
 <% end %>
 <% testfilename = DmsfFile.storage_path.join('test.test') %>
 <% if File.exist?(storage_dir) %>
-  <%	begin %>
-    <% File.open(testfilename, 'wb') %>
+  <% begin %>
+    <% File.open(testfilename, 'wb') {} %>
   <% rescue %>
     <p class="warning"><%= l(:error_file_can_not_be_created) %></p>
-  <%	ensure %>
+  <% ensure %>
     <% FileUtils.rm_f(testfilename) %>
   <% end %>
 <% end %>
@@ -108,12 +108,12 @@
 <% path = Pathname.new(tmpdir) %>
 <% testfilename = path.join('test.test') %>
 <% if File.exist?(tmpdir) %>
-  <%	begin %>
-    <% File.open(testfilename, 'wb') %>
+  <% begin %>
+    <% File.open(testfilename, 'wb') {} %>
   <% rescue %>
     <p class="warning"><%= l(:error_tmpfile_can_not_be_created) %></p>
-  <%	ensure %>
-    <% File.delete(testfilename) if File.exist?(testfilename) %>
+  <% ensure %>
+    <% FileUtils.rm_f(testfilename) %>
   <% end %>
 <% end %>
 
diff --git a/lib/dav4rack/controller.rb b/lib/dav4rack/controller.rb
index f75086dd..da77a260 100644
--- a/lib/dav4rack/controller.rb
+++ b/lib/dav4rack/controller.rb
@@ -102,12 +102,14 @@ module DAV4Rack
     # Return response to HEAD
     def head
       if(resource.exist?)
-        response['Etag'] = resource.etag
-        response['Content-Type'] = resource.content_type
-        response['Content-Length'] = resource.content_length.to_s
-        response['Last-Modified'] = resource.last_modified.httpdate
-        resource.head(request, response)
-        OK
+        res = resource.head(request, response)
+        if(res == OK)
+          response['Etag'] ||= resource.etag
+          response['Content-Type'] ||= resource.content_type
+          response['Content-Length'] ||= resource.content_length.to_s
+          response['Last-Modified'] ||= resource.last_modified.httpdate
+        end
+        res
       else
         NotFound
       end
@@ -197,7 +199,8 @@ module DAV4Rack
       return BadRequest unless request.depth == :infinity
 
       return BadRequest unless dest = request.destination
-      if status = dest.validate
+      if status = dest.validate(host: request.host,
+                                resource_path: resource.path)
         return status
       end
 
diff --git a/lib/dav4rack/destination_header.rb b/lib/dav4rack/destination_header.rb
index fe43e7e1..bdaae6ec 100644
--- a/lib/dav4rack/destination_header.rb
+++ b/lib/dav4rack/destination_header.rb
@@ -5,24 +5,13 @@ module DAV4Rack
 
     attr_reader :host, :path, :path_info
 
-    def initialize(value, script_name: nil)
-      @script_name = script_name.to_s
-      @value = value.to_s.strip
-      parse
-    end
-
-    def parse
-      uri = Addressable::URI.parse @value
-
+    # uri is expected to be a DAV4Rack::Uri instance
+    def initialize(uri)
       @host = uri.host
-      @path = Addressable::URI.unencode uri.path
-
-      if @script_name
-        if @path =~ /\A(?<path>#{Regexp.escape @script_name}(?<path_info>\/.*))\z/
-          @path_info = $~[:path_info]
-        else
-          raise ArgumentError, 'invalid destination header value'
-        end
+      @path = uri.path
+      unless @path_info = uri.path_info
+        # nil path info means path is outside the realm of script_name
+        raise ArgumentError, "invalid destination header value: #{uri.to_s}"
       end
     end
 
@@ -30,7 +19,7 @@ module DAV4Rack
     def validate(host: nil, resource_path: nil)
       if host and self.host and self.host != host
         DAV4Rack::HTTPStatus::BadGateway
-      elsif self.path == resource_path
+      elsif resource_path and self.path_info == resource_path
         DAV4Rack::HTTPStatus::Forbidden
       end
     end
diff --git a/lib/dav4rack/request.rb b/lib/dav4rack/request.rb
index 7851988b..3a867db7 100644
--- a/lib/dav4rack/request.rb
+++ b/lib/dav4rack/request.rb
@@ -3,6 +3,7 @@
 require 'uri'
 require 'addressable/uri'
 require 'dav4rack/logger'
+require 'dav4rack/uri'
 
 module DAV4Rack
   class Request < Rack::Request
@@ -84,7 +85,7 @@ module DAV4Rack
     # Destination header
     def destination
       @destination ||= if h = get_header('HTTP_DESTINATION')
-        DestinationHeader.new h, script_name: script_name
+        DestinationHeader.new DAV4Rack::Uri.new(h, script_name: script_name)
       end
     end
 
@@ -123,6 +124,13 @@ module DAV4Rack
       "#{script_name}#{expand_path path}"
     end
 
+    # returns the given path, but with the leading script_name removed. Will
+    # return nil if the path does not begin with the script_name
+    def path_info_for(full_path, script_name: self.script_name)
+      uri = DAV4Rack::Uri.new full_path, script_name: script_name
+      return uri.path_info
+    end
+
     # expands '/foo/../bar' to '/bar'
     def expand_path(path)
       path.squeeze! '/'
diff --git a/lib/dav4rack/resource.rb b/lib/dav4rack/resource.rb
index 2981e852..6eb62d3e 100644
--- a/lib/dav4rack/resource.rb
+++ b/lib/dav4rack/resource.rb
@@ -208,8 +208,12 @@ module DAV4Rack
       NotImplemented
     end
 
+    # HTTP HEAD request.
+    #
+    # Like GET, but without content. Override if you set custom headers in GET
+    # to set them here as well.
     def head(request, response)
-       #no-op, but called by the controller
+      OK
     end
 
     # HTTP PUT request.
diff --git a/lib/dav4rack/uri.rb b/lib/dav4rack/uri.rb
new file mode 100644
index 00000000..20a5dbcf
--- /dev/null
+++ b/lib/dav4rack/uri.rb
@@ -0,0 +1,42 @@
+require 'addressable/uri'
+
+module DAV4Rack
+
+  # adds a bit of parsing logic around a header URI or path value
+  class Uri
+
+    attr_reader :host, :path, :path_info, :script_name
+
+    def initialize(uri_or_path, script_name: nil)
+      # more than one leading slash confuses Addressable::URI, resulting e.g.
+      # with //remote.php/dav/files in a path of /dav/files with a host
+      # remote.php.
+      @uri_or_path = uri_or_path.to_s.strip.sub %r{\A/+}, '/'
+
+      @script_name = script_name
+      parse
+    end
+
+    def to_s
+      @uri_or_path
+    end
+
+    private
+
+    def parse
+      uri = Addressable::URI.parse @uri_or_path
+
+      @host = uri.host
+      @path = Addressable::URI.unencode uri.path
+
+      if @script_name
+        if @path =~ /\A(?<path>#{Regexp.escape @script_name}(?<path_info>\/.*))\z/
+          @path_info = $~[:path_info]
+        end
+      else
+        @path_info = @path
+      end
+    end
+
+  end
+end
diff --git a/lib/dav4rack/version.rb b/lib/dav4rack/version.rb
index 221a3e9a..d386f6c5 100644
--- a/lib/dav4rack/version.rb
+++ b/lib/dav4rack/version.rb
@@ -13,5 +13,5 @@ module DAV4Rack
     end
   end
 
-  VERSION = Version.new('1.0.0')
+  VERSION = Version.new('1.1.0')
 end
diff --git a/test/unit/dmsf_workflow_step_test.rb b/test/unit/dmsf_workflow_step_test.rb
index 77b2b55a..cd0b5e36 100644
--- a/test/unit/dmsf_workflow_step_test.rb
+++ b/test/unit/dmsf_workflow_step_test.rb
@@ -72,25 +72,25 @@ class DmsfWorkflowStepTest < RedmineDmsf::Test::UnitTest
   def test_validate_workflow_id_presence
     @wfs1.dmsf_workflow_id = nil
     assert !@wfs1.save
-    assert@wfs1.errors.count > 0
+    assert @wfs1.errors.any?
   end
   
   def test_validate_step_presence
     @wfs1.step = nil
     assert !@wfs1.save
-    assert @wfs1.errors.count > 0
+    assert @wfs1.errors.any?
   end
   
   def test_validate_user_id_presence
     @wfs1.user_id = nil
     assert !@wfs1.save
-    assert@wfs1.errors.count > 0
+    assert @wfs1.errors.any?
   end
   
   def test_validate_operator_presence
     @wfs1.operator = nil
     assert !@wfs1.save
-    assert @wfs1.errors.count > 0
+    assert @wfs1.errors.any?
   end
   
   def test_validate_user_id_uniqueness
@@ -98,7 +98,7 @@ class DmsfWorkflowStepTest < RedmineDmsf::Test::UnitTest
     @wfs2.dmsf_workflow_id = @wfs1.dmsf_workflow_id
     @wfs2.step = @wfs1.step
     assert !@wfs2.save
-    assert @wfs2.errors.count > 0
+    assert @wfs2.errors.any?
   end
 
   def test_validate_name_length