Merge csv-3.0.0 from ruby/csv repository.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64638 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 22 insertions, 8 deletions

diff --git a/lib/csv.rb b/lib/csv.rb
index ebb6d67968..dca2a45b6a 100644
--- a/lib/csv.rb
+++ b/lib/csv.rb
@@ -141,7 +141,7 @@ end
 # There are several specialized class methods for one-statement reading or writing,
 # described in the Specialized Methods section.
 #
-# If a String passed into ::new, it is internally wrapped into a StringIO object.
+# If a String is passed into ::new, it is internally wrapped into a StringIO object.
 #
 # +options+ can be used for specifying the particular CSV flavor (column
 # separators, row separators, value quoting and so on), and for data conversion,
@@ -890,8 +890,12 @@ class CSV
   #                                       attempt to parse input not conformant
   #                                       with RFC 4180, such as double quotes
   #                                       in unquoted fields.
-  # <b><tt>:nil_value</tt></b>::          TODO: WRITE ME.
-  # <b><tt>:empty_value</tt></b>::        TODO: WRITE ME.
+  # <b><tt>:nil_value</tt></b>::          When set an object, any values of an
+  #                                       empty field are replaced by the set
+  #                                       object, not nil.
+  # <b><tt>:empty_value</tt></b>::        When set an object, any values of a
+  #                                       blank string field is replaced by
+  #                                       the set object.
   #
   # See CSV::DEFAULT_OPTIONS for the default settings.
   #
@@ -1232,7 +1236,7 @@ class CSV
           elsif @unconverted_fields
             return add_unconverted_fields(Array.new, Array.new)
           elsif @use_headers
-            return self.class::Row.new(Array.new, Array.new)
+            return self.class::Row.new(@headers, Array.new)
           else
             return Array.new
           end
diff --git a/lib/csv/csv.gemspec b/lib/csv/csv.gemspec
index 0169c173d6..9d0ccc15af 100644
--- a/lib/csv/csv.gemspec
+++ b/lib/csv/csv.gemspec
@@ -1,6 +1,10 @@
 # frozen_string_literal: true
 
-require_relative "version"
+begin
+  require_relative "lib/csv/version"
+rescue LoadError
+  require_relative "version"
+end
 
 Gem::Specification.new do |spec|
   spec.name          = "csv"
@@ -13,7 +17,8 @@ Gem::Specification.new do |spec|
   spec.homepage      = "https://github.com/ruby/csv"
   spec.license       = "BSD-2-Clause"
 
-  spec.files         = ["lib/csv.rb", "lib/csv/table.rb", "lib/csv/core_ext/string.rb", "lib/csv/core_ext/array.rb", "lib/csv/row.rb", "lib/csv/version.rb", "README.md", "LICENSE.txt", "news.md"]
+  spec.files         = Dir.glob("lib/**/*.rb")
+  spec.files         += ["README.md", "LICENSE.txt", "news.md"]
   spec.require_paths = ["lib"]
   spec.required_ruby_version = ">= 2.3.0"
 
diff --git a/lib/csv/row.rb b/lib/csv/row.rb
index 8ff3480ae8..31eab2d0a4 100644
--- a/lib/csv/row.rb
+++ b/lib/csv/row.rb
@@ -48,6 +48,11 @@ class CSV
     extend Forwardable
     def_delegators :@row, :empty?, :length, :size
 
+    def initialize_copy(other)
+      super
+      @row = @row.dup
+    end
+
     # Returns +true+ if this is a header row.
     def header_row?
       @header_row
diff --git a/lib/csv/table.rb b/lib/csv/table.rb
index 17a7c542e4..e9f3366a4a 100644
--- a/lib/csv/table.rb
+++ b/lib/csv/table.rb
@@ -375,4 +375,4 @@ class CSV
       "#<#{self.class} mode:#{@mode} row_count:#{to_a.size}>".encode("US-ASCII")
     end
   end
-end
+end
\ No newline at end of file
diff --git a/lib/csv/version.rb b/lib/csv/version.rb
index 35adea3a92..d62a093418 100644
--- a/lib/csv/version.rb
+++ b/lib/csv/version.rb
@@ -2,5 +2,5 @@
 
 class CSV
   # The version of the installed library.
-  VERSION = "1.0.2"
+  VERSION = "3.0.1"
 end