From 3ecc701b4858f74d0689bc65e62fd874f6abab7c Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 18:22:16 +0000
Subject: [PATCH 01/20] EmbeddedFile PDF object definition

---
 lib/prawn/embedded_files/embedded_file.rb | 42 +++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 lib/prawn/embedded_files/embedded_file.rb

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
new file mode 100644
index 000000000..3130df837
--- /dev/null
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'digest/md5'
+
+module Prawn
+  module EmbeddedFiles
+    class EmbeddedFile
+      attr_reader :chksum
+
+      def initialize(data, options = {})
+        @creation_date = options[:creation_date]
+        unless @creation_date.instance_of?(Time)
+          @creation_date = Time.now.utc
+        end
+
+        @mod_date = options[:modification_date]
+        unless @mod_date.instance_of?(Time)
+          @mod_date = Time.now.utc
+        end
+
+        @chksum = Digest::MD5.hexdigest(data)
+        @data = data.dup
+      end
+
+      def build_pdf_object(document)
+        obj = document.ref!(
+          Type: :EmbeddedFile,
+          Params: {
+            CreationDate: @creation_date,
+            ModDate: @mod_date,
+            CheckSum: PDF::Core::LiteralString.new(@chksum),
+            Size: @data.length
+          }
+        )
+
+        obj << @data
+        obj.stream.compress!
+        obj
+      end
+    end
+  end
+end

From 375f85e2aa16b2d0672634d4c4946d9006e02519 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 18:22:36 +0000
Subject: [PATCH 02/20] Filespec PDF object definition

---
 lib/prawn/embedded_files/filespec.rb | 42 ++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 lib/prawn/embedded_files/filespec.rb

diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
new file mode 100644
index 000000000..465c8459e
--- /dev/null
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+module Prawn
+  module EmbeddedFiles
+    class Filespec
+      attr_reader :file_name, :not_hidden
+
+      def initialize(file, options = {})
+        name = options[:name] || file.chksum
+
+        @file_name = PDF::Core::LiteralString.new(name)
+
+        if options[:description]
+          desc_str = options[:description].to_s
+          @description = PDF::Core::LiteralString.new(desc_str)
+        end
+
+        if options[:hidden].nil? || options[:hidden] != true
+          @not_hidden = true
+        end
+
+        @file = file
+      end
+
+      def hidden
+        !@not_hidden
+      end
+
+      def build_pdf_object(document)
+        obj = document.ref!(
+          Type: :Filespec,
+          F: @file_name,
+          EF: { F: @file },
+          UF: @file_name
+        )
+
+        obj[:Desc] = @description if @description
+        obj
+      end
+    end
+  end
+end

From 83a0642c86e41d3c3d1765fa5b0006532b3486d2 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 18:24:15 +0000
Subject: [PATCH 03/20] Document file attachment method definition

---
 lib/prawn/embedded_files.rb | 43 +++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 lib/prawn/embedded_files.rb

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
new file mode 100644
index 000000000..5d086f605
--- /dev/null
+++ b/lib/prawn/embedded_files.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module Prawn
+  module EmbeddedFiles
+    # include PDF::Core::EmbeddedFiles
+    # Link to PR (https://github.com/prawnpdf/pdf-core/pull/47)
+
+    def file(src, options = {})
+      path = Pathname.new(src)
+
+      if path.directory?
+        raise ArgumentError, 'Data source can\'t be a directory'
+      elsif path.file?
+        data = path.read
+        options[:name] ||= src
+      else
+        data = src
+      end
+
+      @file_registry ||= {}
+
+      file = EmbeddedFile.new(data, options)
+      file_obj = @file_registry[file.chksum]
+
+      if file_obj.nil?
+        file_obj = file.build_pdf_object(self)
+        @file_registry[file.chksum] = file_obj
+      end
+
+      filespec = Filespec.new(file_obj, options)
+      filespec_obj = filespec.build_pdf_object(self)
+
+      unless filespec.hidden
+        # Wait for pdf-core PR
+
+        # attach_file(filespec.file_name, filespec_obj)
+      end
+    end
+  end
+end
+
+require_relative 'embedded_files/embedded_file'
+require_relative 'embedded_files/filespec'

From 9461d9839403dab4dc70f0fce696e9662f040a4c Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 18:26:29 +0000
Subject: [PATCH 04/20] EmbeddedFiles module included in Prawn::Document class
 and lib

---
 lib/prawn.rb          | 1 +
 lib/prawn/document.rb | 1 +
 2 files changed, 2 insertions(+)

diff --git a/lib/prawn.rb b/lib/prawn.rb
index 05f4aeb78..06b441a3d 100644
--- a/lib/prawn.rb
+++ b/lib/prawn.rb
@@ -61,6 +61,7 @@ def verify_options(accepted, actual)
 require_relative 'prawn/images/image'
 require_relative 'prawn/images/jpg'
 require_relative 'prawn/images/png'
+require_relative 'prawn/embedded_files'
 require_relative 'prawn/stamp'
 require_relative 'prawn/soft_mask'
 require_relative 'prawn/security'
diff --git a/lib/prawn/document.rb b/lib/prawn/document.rb
index 439667d5a..03cd472b7 100644
--- a/lib/prawn/document.rb
+++ b/lib/prawn/document.rb
@@ -55,6 +55,7 @@ class Document
     include Prawn::Text
     include Prawn::Graphics
     include Prawn::Images
+    include Prawn::EmbeddedFiles
     include Prawn::Stamp
     include Prawn::SoftMask
     include Prawn::TransformationStack

From 0fb2b56c81a8a16ce8d9fb48967a47071eb00709 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 22:10:17 +0000
Subject: [PATCH 05/20] Creation and modification dates from file information

---
 lib/prawn/embedded_files.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index 5d086f605..7e055ccc8 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -13,6 +13,8 @@ def file(src, options = {})
       elsif path.file?
         data = path.read
         options[:name] ||= src
+        options[:creation_date] ||= path.birthtime
+        options[:modification_date] ||= path.mtime
       else
         data = src
       end

From 334c19a993e3bd0bb10d392751d9d4839a176f4f Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Wed, 21 Jul 2021 22:27:15 +0000
Subject: [PATCH 06/20] :hidden option simplification

---
 lib/prawn/embedded_files.rb          |  2 +-
 lib/prawn/embedded_files/filespec.rb | 11 ++++-------
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index 7e055ccc8..f82af36a6 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -32,7 +32,7 @@ def file(src, options = {})
       filespec = Filespec.new(file_obj, options)
       filespec_obj = filespec.build_pdf_object(self)
 
-      unless filespec.hidden
+      unless filespec.hidden?
         # Wait for pdf-core PR
 
         # attach_file(filespec.file_name, filespec_obj)
diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index 465c8459e..4311ae467 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -3,7 +3,7 @@
 module Prawn
   module EmbeddedFiles
     class Filespec
-      attr_reader :file_name, :not_hidden
+      attr_reader :file_name
 
       def initialize(file, options = {})
         name = options[:name] || file.chksum
@@ -15,15 +15,12 @@ def initialize(file, options = {})
           @description = PDF::Core::LiteralString.new(desc_str)
         end
 
-        if options[:hidden].nil? || options[:hidden] != true
-          @not_hidden = true
-        end
-
+        @hidden = options[:hidden] == true
         @file = file
       end
 
-      def hidden
-        !@not_hidden
+      def hidden?
+        @hidden
       end
 
       def build_pdf_object(document)

From 5680677ffbd7cc188f55f872b9974eb20f3e5ddd Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 11:59:37 +0000
Subject: [PATCH 07/20] :hidden option could be a truthy value

---
 lib/prawn/embedded_files/filespec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index 4311ae467..b1932f7bd 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -15,7 +15,7 @@ def initialize(file, options = {})
           @description = PDF::Core::LiteralString.new(desc_str)
         end
 
-        @hidden = options[:hidden] == true
+        @hidden = options[:hidden]
         @file = file
       end
 

From 6796763a3576d8cd643d8fd4d39070162e7b8bb4 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 12:04:26 +0000
Subject: [PATCH 08/20] Look for the Time class in the object's superclasses as
 well

---
 lib/prawn/embedded_files/embedded_file.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index 3130df837..4a00a8c01 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -9,12 +9,12 @@ class EmbeddedFile
 
       def initialize(data, options = {})
         @creation_date = options[:creation_date]
-        unless @creation_date.instance_of?(Time)
+        unless @creation_date.kind_of?(Time)
           @creation_date = Time.now.utc
         end
 
         @mod_date = options[:modification_date]
-        unless @mod_date.instance_of?(Time)
+        unless @mod_date.kind_of?(Time)
           @mod_date = Time.now.utc
         end
 

From ca636340c8a24dba9d0c0975c7d41a5235841c91 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 12:05:54 +0000
Subject: [PATCH 09/20] Using MD5 digest instead of the hex-encoded one

---
 lib/prawn/embedded_files/embedded_file.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index 4a00a8c01..c9aef49ce 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -18,7 +18,7 @@ def initialize(data, options = {})
           @mod_date = Time.now.utc
         end
 
-        @chksum = Digest::MD5.hexdigest(data)
+        @chksum = Digest::MD5.digest(data)
         @data = data.dup
       end
 

From b96039be0af5dc09327131309e90f332ac8851e0 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 12:06:50 +0000
Subject: [PATCH 10/20] Avoiding wasteful duplication

---
 lib/prawn/embedded_files/embedded_file.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index c9aef49ce..d2ba58889 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -19,7 +19,7 @@ def initialize(data, options = {})
         end
 
         @chksum = Digest::MD5.digest(data)
-        @data = data.dup
+        @data = data
       end
 
       def build_pdf_object(document)

From f41ed2cf09568f09781ea39b833511cf664bafd8 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 22:54:13 +0000
Subject: [PATCH 11/20] Checksum attribute renamed

---
 lib/prawn/embedded_files.rb               | 4 ++--
 lib/prawn/embedded_files/embedded_file.rb | 6 +++---
 lib/prawn/embedded_files/filespec.rb      | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index f82af36a6..0ff128799 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -22,11 +22,11 @@ def file(src, options = {})
       @file_registry ||= {}
 
       file = EmbeddedFile.new(data, options)
-      file_obj = @file_registry[file.chksum]
+      file_obj = @file_registry[file.checksum]
 
       if file_obj.nil?
         file_obj = file.build_pdf_object(self)
-        @file_registry[file.chksum] = file_obj
+        @file_registry[file.checksum] = file_obj
       end
 
       filespec = Filespec.new(file_obj, options)
diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index d2ba58889..adf9c7f66 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -5,7 +5,7 @@
 module Prawn
   module EmbeddedFiles
     class EmbeddedFile
-      attr_reader :chksum
+      attr_reader :checksum
 
       def initialize(data, options = {})
         @creation_date = options[:creation_date]
@@ -18,7 +18,7 @@ def initialize(data, options = {})
           @mod_date = Time.now.utc
         end
 
-        @chksum = Digest::MD5.digest(data)
+        @checksum = Digest::MD5.digest(data)
         @data = data
       end
 
@@ -28,7 +28,7 @@ def build_pdf_object(document)
           Params: {
             CreationDate: @creation_date,
             ModDate: @mod_date,
-            CheckSum: PDF::Core::LiteralString.new(@chksum),
+            CheckSum: PDF::Core::LiteralString.new(@checksum),
             Size: @data.length
           }
         )
diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index b1932f7bd..33619531b 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -6,7 +6,7 @@ class Filespec
       attr_reader :file_name
 
       def initialize(file, options = {})
-        name = options[:name] || file.chksum
+        name = options[:name] || file.checksum
 
         @file_name = PDF::Core::LiteralString.new(name)
 

From f0c04536a9b56c054ffd67e797047f6a835439f6 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 23:02:12 +0000
Subject: [PATCH 12/20] Filespec description key set wrongly fixed

---
 lib/prawn/embedded_files/filespec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index 33619531b..18fa786d3 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -31,7 +31,7 @@ def build_pdf_object(document)
           UF: @file_name
         )
 
-        obj[:Desc] = @description if @description
+        obj.data[:Desc] = @description if @description
         obj
       end
     end

From a6343c1c02d77cb1517986b4ec4990a047bc95a7 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 23:24:32 +0000
Subject: [PATCH 13/20] Avoiding instance variables outside  method

---
 lib/prawn/embedded_files/embedded_file.rb | 20 ++++++++++++--------
 lib/prawn/embedded_files/filespec.rb      | 12 ++++++++----
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index adf9c7f66..bd4d7b1fb 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -13,9 +13,9 @@ def initialize(data, options = {})
           @creation_date = Time.now.utc
         end
 
-        @mod_date = options[:modification_date]
-        unless @mod_date.kind_of?(Time)
-          @mod_date = Time.now.utc
+        @modification_date = options[:modification_date]
+        unless @modification_date.kind_of?(Time)
+          @modification_date = Time.now.utc
         end
 
         @checksum = Digest::MD5.digest(data)
@@ -26,17 +26,21 @@ def build_pdf_object(document)
         obj = document.ref!(
           Type: :EmbeddedFile,
           Params: {
-            CreationDate: @creation_date,
-            ModDate: @mod_date,
-            CheckSum: PDF::Core::LiteralString.new(@checksum),
-            Size: @data.length
+            CreationDate: creation_date,
+            ModDate: modification_date,
+            CheckSum: PDF::Core::LiteralString.new(checksum),
+            Size: data.length
           }
         )
 
-        obj << @data
+        obj << data
         obj.stream.compress!
         obj
       end
+
+      private
+
+      attr_reader :data, :creation_date, :modification_date
     end
   end
 end
diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index 18fa786d3..c79e89bd0 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -26,14 +26,18 @@ def hidden?
       def build_pdf_object(document)
         obj = document.ref!(
           Type: :Filespec,
-          F: @file_name,
-          EF: { F: @file },
-          UF: @file_name
+          F: file_name,
+          EF: { F: file },
+          UF: file_name
         )
 
-        obj.data[:Desc] = @description if @description
+        obj.data[:Desc] = description if description
         obj
       end
+
+      private
+
+      attr_reader :file, :description
     end
   end
 end

From fe6486098311018a0ded5e19130b2b0fd358e6dc Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 23:46:54 +0000
Subject: [PATCH 14/20] Honoring document compression option

---
 lib/prawn/embedded_files/embedded_file.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index bd4d7b1fb..0ac6c0ebb 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -34,7 +34,7 @@ def build_pdf_object(document)
         )
 
         obj << data
-        obj.stream.compress!
+        obj.stream.compress! if document.compression_enabled?
         obj
       end
 

From 8d4e0471c13edb08a84f0e7bc6d439ef09545f6d Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Thu, 22 Jul 2021 23:57:56 +0000
Subject: [PATCH 15/20] Avoiding changes of parameters

---
 lib/prawn/embedded_files.rb | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index 0ff128799..699be8a97 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -7,21 +7,22 @@ module EmbeddedFiles
 
     def file(src, options = {})
       path = Pathname.new(src)
+      mut_opts = options.dup
 
       if path.directory?
         raise ArgumentError, 'Data source can\'t be a directory'
       elsif path.file?
         data = path.read
-        options[:name] ||= src
-        options[:creation_date] ||= path.birthtime
-        options[:modification_date] ||= path.mtime
+        mut_opts[:name] ||= src
+        mut_opts[:creation_date] ||= path.birthtime
+        mut_opts[:modification_date] ||= path.mtime
       else
         data = src
       end
 
       @file_registry ||= {}
 
-      file = EmbeddedFile.new(data, options)
+      file = EmbeddedFile.new(data, mut_opts)
       file_obj = @file_registry[file.checksum]
 
       if file_obj.nil?
@@ -29,7 +30,7 @@ def file(src, options = {})
         @file_registry[file.checksum] = file_obj
       end
 
-      filespec = Filespec.new(file_obj, options)
+      filespec = Filespec.new(file_obj, mut_opts)
       filespec_obj = filespec.build_pdf_object(self)
 
       unless filespec.hidden?

From 484d7011d77dbedf3bf98dede05c11b91c204176 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Fri, 23 Jul 2021 10:59:53 +0000
Subject: [PATCH 16/20] Using hex-encoded digest as default name

---
 lib/prawn/embedded_files/embedded_file.rb | 2 +-
 lib/prawn/embedded_files/filespec.rb      | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index 0ac6c0ebb..867f2e6c0 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'digest/md5'
+require 'digest'
 
 module Prawn
   module EmbeddedFiles
diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index c79e89bd0..41646cbaa 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -1,12 +1,15 @@
 # frozen_string_literal: true
 
+require 'digest'
+
 module Prawn
   module EmbeddedFiles
     class Filespec
       attr_reader :file_name
 
       def initialize(file, options = {})
-        name = options[:name] || file.checksum
+        hexdigest = Digest.hexencode(file.data[:Params][:CheckSum])
+        name = options[:name] || hexdigest
 
         @file_name = PDF::Core::LiteralString.new(name)
 

From 097ee850de27e86bbba51788f348fedc64e1ed18 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Fri, 23 Jul 2021 11:04:19 +0000
Subject: [PATCH 17/20] Setting 'UF' entry in the 'EF' dictionary as well

---
 lib/prawn/embedded_files/filespec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/prawn/embedded_files/filespec.rb b/lib/prawn/embedded_files/filespec.rb
index 41646cbaa..07b51337b 100644
--- a/lib/prawn/embedded_files/filespec.rb
+++ b/lib/prawn/embedded_files/filespec.rb
@@ -30,7 +30,7 @@ def build_pdf_object(document)
         obj = document.ref!(
           Type: :Filespec,
           F: file_name,
-          EF: { F: file },
+          EF: { F: file, UF: file },
           UF: file_name
         )
 

From 8f09896d68c97a4de08d064fc8fafe167f7e46e6 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Tue, 27 Jul 2021 15:24:28 +0000
Subject: [PATCH 18/20] 'file' method documentation

---
 lib/prawn/embedded_files.rb | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index 699be8a97..a9a9c29ad 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -5,6 +5,30 @@ module EmbeddedFiles
     # include PDF::Core::EmbeddedFiles
     # Link to PR (https://github.com/prawnpdf/pdf-core/pull/47)
 
+    # Add the file's data from a source to the document. Any kind of data with
+    # a string representation can be embedded.
+    #
+    # Arguments:
+    # <tt>src</tt>:: path to file, string or an object that responds to #to_str
+    # and #length.
+    #
+    # Options:
+    # <tt>:name</tt>:: explicit default filename override.
+    # <tt>:creation_date</tt>:: date when the file was created.
+    # <tt>:modification_date</tt>::  date when the file was last modified.
+    # <tt>:description</tt>:: file description.
+    # <tt>:hidden</tt>:: if true, prevents the file from appearing in the
+    # catalog. (default false)
+    #
+    #   Prawn::Document.generate("file1.pdf") do
+    #     dice = "#{Prawn::DATADIR}/images/dice.png"
+    #     file dice, description: 'Example of an embedded image file'
+    #   end
+    #
+    # This method returns an instance of PDF::Core::NameTree::Value
+    # corresponding to the file in the embedded files catalog entry node. If
+    # hidden, then nil is returned.
+    #
     def file(src, options = {})
       path = Pathname.new(src)
       mut_opts = options.dup

From 5d3011e9521dbb93c497ceda7b5a4a325b2bbc41 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Tue, 27 Jul 2021 15:25:04 +0000
Subject: [PATCH 19/20] File registration refactor

---
 lib/prawn/embedded_files.rb | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/prawn/embedded_files.rb b/lib/prawn/embedded_files.rb
index a9a9c29ad..01af76343 100644
--- a/lib/prawn/embedded_files.rb
+++ b/lib/prawn/embedded_files.rb
@@ -44,14 +44,12 @@ def file(src, options = {})
         data = src
       end
 
-      @file_registry ||= {}
-
       file = EmbeddedFile.new(data, mut_opts)
-      file_obj = @file_registry[file.checksum]
+      file_obj = file_registry[file.checksum]
 
       if file_obj.nil?
         file_obj = file.build_pdf_object(self)
-        @file_registry[file.checksum] = file_obj
+        file_registry[file.checksum] = file_obj
       end
 
       filespec = Filespec.new(file_obj, mut_opts)
@@ -63,6 +61,12 @@ def file(src, options = {})
         # attach_file(filespec.file_name, filespec_obj)
       end
     end
+
+    private
+
+    def file_registry
+      @file_registry ||= {}
+    end
   end
 end
 

From 3714d596652a7a32fb75c3243b3472282c397d35 Mon Sep 17 00:00:00 2001
From: David Lilue <2525462+dvdalilue@users.noreply.github.com>
Date: Fri, 13 Aug 2021 18:50:09 +0000
Subject: [PATCH 20/20] 'is_a?' is preferable to 'kind_of?'

---
 lib/prawn/embedded_files/embedded_file.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/prawn/embedded_files/embedded_file.rb b/lib/prawn/embedded_files/embedded_file.rb
index 867f2e6c0..524092071 100644
--- a/lib/prawn/embedded_files/embedded_file.rb
+++ b/lib/prawn/embedded_files/embedded_file.rb
@@ -9,12 +9,12 @@ class EmbeddedFile
 
       def initialize(data, options = {})
         @creation_date = options[:creation_date]
-        unless @creation_date.kind_of?(Time)
+        unless @creation_date.is_a?(Time)
           @creation_date = Time.now.utc
         end
 
         @modification_date = options[:modification_date]
-        unless @modification_date.kind_of?(Time)
+        unless @modification_date.is_a?(Time)
           @modification_date = Time.now.utc
         end