Don't build quoted_fields array when not needed

Author: marshall-lee

benchmark/convert_nil.yaml

@@ -4,6 +4,8 @@ contexts:
       csv: 3.0.1
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/parse.yaml

@@ -4,6 +4,8 @@ contexts:
       csv: 3.0.1
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/parse_liberal_parsing.yaml

@@ -2,6 +2,8 @@ loop_count: 100
 contexts:
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/parse_quote_char_nil.yaml

@@ -1,5 +1,7 @@
 loop_count: 100
 contexts:
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/parse_strip.yaml

@@ -1,5 +1,7 @@
 loop_count: 100
 contexts:
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/read.yaml

@@ -4,6 +4,8 @@ contexts:
       csv: 3.0.1
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/shift.yaml

@@ -4,6 +4,8 @@ contexts:
       csv: 3.0.1
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

benchmark/write.yaml

@@ -4,6 +4,8 @@ contexts:
       csv: 3.0.1
   - gems:
       csv: 3.0.2
+  - gems:
+      csv: 3.3.0
   - name: "master"
     prelude: |
       $LOAD_PATH.unshift(File.expand_path("lib"))

lib/csv.rb

@@ -959,6 +959,12 @@ def initialize(encoding, line_number)
     write_empty_value:  "",
   }.freeze
 
+  module NoQuotedFields # :nodoc:
+    def self.[](_index)
+      false
+    end
+  end
+
   class << self
     # :call-seq:
     #   instance(string, **options)

lib/csv/fields_converter.rb

@@ -44,7 +44,7 @@ def empty?
       @converters.empty?
     end
 
-    def convert(fields, headers, lineno, quoted_fields)
+    def convert(fields, headers, lineno, quoted_fields = NoQuotedFields)
       return fields unless need_convert?
 
       fields.collect.with_index do |field, index|