devopsgroup-io#282

- Probably an universal solution for the line ending problem: Read the file, ignore how it converted line endings and just convert it to universal newline, then work on it also using just universal newlines. Comparison of old and new content then works. Finally, just write the file using universal newlines on all systems except Windows, where we convert to CRLF

lib/vagrant-hostmanager/hosts_file/updater.rb

@@ -19,17 +19,17 @@ def update_guest(machine)
 
           if (machine.communicate.test("uname -s | grep SunOS"))
             realhostfile = "/etc/inet/hosts"
-            line_endings = "lf"
+            is_windows = false
           elsif (machine.communicate.test("test -d $Env:SystemRoot"))
             windir = ""
             machine.communicate.execute("echo %SYSTEMROOT%", {:shell => :cmd}) do |type, contents|
               windir << contents.gsub("\r\n", '') if type == :stdout
             end
             realhostfile = "#{windir}\\System32\\drivers\\etc\\hosts"
-            line_endings = "crlf"
+            is_windows = true
           else
             realhostfile = "/etc/hosts"
-            line_endings = "lf"
+            is_windows = false
           end
 
           # download and modify file with Vagrant-managed entries
@@ -39,7 +39,7 @@ def update_guest(machine)
           @logger.debug("file is: #{file.to_s}")
           @logger.debug("class of file is: #{file.class}")
 
-          if update_file(file, machine, false, line_endings)
+          if update_file(file, machine, false, is_windows)
             # upload modified file and remove temporary file
             machine.communicate.upload(file.to_s, "/tmp/hosts.#{machine.name}")
             if windir
@@ -62,38 +62,44 @@ class << self
             end
             hosts_location = "#{ENV['WINDIR']}\\System32\\drivers\\etc\\hosts"
             copy_proc = Proc.new { windows_copy_file(file, hosts_location) }
-            line_endings = "crlf"
+            is_windows=true
           else
             hosts_location = '/etc/hosts'
             copy_proc = Proc.new { `[ -w "#{hosts_location}" ] && cat "#{file}" > "#{hosts_location}" || sudo cp "#{file}" "#{hosts_location}"` }
-            line_endings = "lf"
+            is_windows=false
           end
 
           FileUtils.cp(hosts_location, file)
 
-          if update_file(file, nil, true, line_endings)
+          if update_file(file, nil, true, is_windows)
             copy_proc.call
           end
         end
 
         private
 
-        def update_file(file, resolving_machine = nil, include_id = true, line_endings)
+        def update_file(file, resolving_machine = nil, include_id = true, is_windows)
           file = Pathname.new(file)
           old_file_content = file.read
-          new_file_content = update_content(old_file_content, resolving_machine, include_id, line_endings)
+          # Don't care what's been read by Pathname, just convert to universal line endings for comparison
+          old_file_content = old_file_content.encode(old_file_content.encoding, universal_newline: true)
+          new_file_content = update_content(old_file_content, resolving_machine, include_id)
+          if is_windows
+            new_file_content = new_file_content.encode(new_file_content.encoding, :crlf_newline => true)
+          end
+
           file.open('wb') { |io| io.write(new_file_content) }
           old_file_content != new_file_content
         end
 
-        def update_content(file_content, resolving_machine, include_id, line_endings)
+        def update_content(file_content, resolving_machine, include_id)
           id = include_id ? " id: #{read_or_create_id}" : ""
           header = "## vagrant-hostmanager-start#{id}"
           footer = "## vagrant-hostmanager-end"
           body = get_machines
             .map { |machine| get_hosts_file_entry(machine, resolving_machine) }
             .join
-          get_new_content(header, footer, body, file_content, line_endings)
+          get_new_content(header, footer, body, file_content)
         end
 
         def get_hosts_file_entry(machine, resolving_machine)
@@ -142,7 +148,7 @@ def get_machines
             .reject(&:nil?)
         end
 
-        def get_new_content(header, footer, body, old_content, line_endings)
+        def get_new_content(header, footer, body, old_content)
           if body.empty?
             block = "\n"
           else
@@ -151,16 +157,9 @@ def get_new_content(header, footer, body, old_content, line_endings)
           # Pattern for finding existing block
           header_pattern = Regexp.quote(header)
           footer_pattern = Regexp.quote(footer)
-          pattern = Regexp.new("[\r\n]*#{header_pattern}.*?#{footer_pattern}[\r\n]*", Regexp::MULTILINE)
+          pattern = Regexp.new("[\n]*#{header_pattern}.*?#{footer_pattern}[\n]*", Regexp::MULTILINE)
           # Replace existing block or append
           content = old_content.match(pattern) ? old_content.sub(pattern, block) : old_content.rstrip + block
-          if line_endings == "crlf"
-            content.encode(content.encoding, :universal_encoding => true).encode(content.encoding, :crlf_newline => true)
-          elsif line_endings == "lf"
-            content.encode(content.encoding, :universal_encoding => true)
-          else
-            content.encode(content.encoding, :universal_encoding => true)
-          end
         end
 
         def read_or_create_id