diff --git a/.gitignore b/.gitignore
index c464927386..3a4d0f5a61 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@
 **/vendor/bundle
 **/vendor/ruby
 **/vendor/bundle-standalone/ruby/*/bin
+**/vendor/bundle-standalone/ruby/*/build_info/
 **/vendor/bundle-standalone/ruby/*/cache
 **/vendor/bundle-standalone/ruby/*/extensions
 **/vendor/bundle-standalone/ruby/*/gems/*/*
@@ -93,15 +94,33 @@
 
 # Ignore rubocop's (and other) dependencies we don't wish to vendor
 **/vendor/bundle-standalone/ruby/*/gems/ast-*/
+**/vendor/bundle-standalone/ruby/*/gems/connection_pool-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/domain_name-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/http-cookie-*/lib
 **/vendor/bundle-standalone/ruby/*/gems/jaro_winkler-*/
+**/vendor/bundle-standalone/ruby/*/gems/mime-types-data-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/mime-types-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/mini_portile2-*/lib
 **/vendor/bundle-standalone/ruby/*/gems/minitest-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/net-http-digest_auth-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/net-http-persistent-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/nokogiri-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/ntlm-http-*/lib
 **/vendor/bundle-standalone/ruby/*/gems/parallel-*/
 **/vendor/bundle-standalone/ruby/*/gems/parser-*/
 **/vendor/bundle-standalone/ruby/*/gems/powerpack-*/
 **/vendor/bundle-standalone/ruby/*/gems/rainbow-*/
 **/vendor/bundle-standalone/ruby/*/gems/rubocop-0*/
 **/vendor/bundle-standalone/ruby/*/gems/ruby-progressbar-*/
+**/vendor/bundle-standalone/ruby/*/gems/unf_ext-*/lib
+**/vendor/bundle-standalone/ruby/*/gems/unf-*/lib
 **/vendor/bundle-standalone/ruby/*/gems/unicode-display_width-*/
+**/vendor/bundle-standalone/ruby/*/gems/webrobots-*/lib
+
+# Only include the `Mechanize::HTTP::ContentDispositionParser`.
+**/vendor/bundle-standalone/ruby/*/gems/mechanize-*/lib
+!**/vendor/bundle-standalone/ruby/*/gems/mechanize-*/lib/mechanize/http/content_disposition_parser.rb
+!**/vendor/bundle-standalone/ruby/*/gems/mechanize-*/lib/mechanize/version.rb
 
 # Ignore `bin` contents (again).
 /bin
diff --git a/Library/Homebrew/download_strategy.rb b/Library/Homebrew/download_strategy.rb
index 71a4b58ad8..3e86038a75 100644
--- a/Library/Homebrew/download_strategy.rb
+++ b/Library/Homebrew/download_strategy.rb
@@ -5,6 +5,9 @@ require "unpack_strategy"
 require "lazy_object"
 require "cgi"
 
+require "mechanize/version"
+require "mechanize/http/content_disposition_parser"
+
 class AbstractDownloadStrategy
   extend Forwardable
   include FileUtils
@@ -363,9 +366,20 @@ class CurlDownloadStrategy < AbstractFileDownloadStrategy
       end
     end
 
-    filenames =
-      lines.map { |line| line[/^Content\-Disposition:\s*(?:inline|attachment);\s*filename=(["']?)([^;]+)\1/i, 2] }
-           .compact
+    content_disposition_parser = Mechanize::HTTP::ContentDispositionParser.new
+
+    parse_content_disposition = lambda do |line|
+      next unless content_disposition = content_disposition_parser.parse(line, true)
+
+      if filename_with_encoding = content_disposition.parameters["filename*"]
+        encoding, encoded_filename = filename_with_encoding.split("''", 2)
+        URI.decode_www_form_component(encoded_filename).encode(encoding)
+      else
+        content_disposition.filename
+      end
+    end
+
+    filenames = lines.map(&parse_content_disposition).compact
 
     time =
       lines.map { |line| line[/^Last\-Modified:\s*(.+)/i, 1] }
diff --git a/Library/Homebrew/vendor/Gemfile b/Library/Homebrew/vendor/Gemfile
index 271f3ccfa1..043c518a8f 100644
--- a/Library/Homebrew/vendor/Gemfile
+++ b/Library/Homebrew/vendor/Gemfile
@@ -3,6 +3,7 @@ source "https://rubygems.org"
 gem "activesupport"
 gem "concurrent-ruby"
 gem "backports"
+gem "mechanize"
 gem "plist"
 gem "ruby-macho"
 gem "rubocop-rspec"
diff --git a/Library/Homebrew/vendor/Gemfile.lock b/Library/Homebrew/vendor/Gemfile.lock
index 4b76916791..cbb0bd6da9 100644
--- a/Library/Homebrew/vendor/Gemfile.lock
+++ b/Library/Homebrew/vendor/Gemfile.lock
@@ -9,10 +9,34 @@ GEM
     ast (2.4.0)
     backports (3.11.4)
     concurrent-ruby (1.1.4)
+    connection_pool (2.2.2)
+    domain_name (0.5.20180417)
+      unf (>= 0.0.5, < 1.0.0)
+    http-cookie (1.0.3)
+      domain_name (~> 0.5)
     i18n (1.5.3)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.2)
+    mechanize (2.7.6)
+      domain_name (~> 0.5, >= 0.5.1)
+      http-cookie (~> 1.0)
+      mime-types (>= 1.17.2)
+      net-http-digest_auth (~> 1.1, >= 1.1.1)
+      net-http-persistent (>= 2.5.2)
+      nokogiri (~> 1.6)
+      ntlm-http (~> 0.1, >= 0.1.1)
+      webrobots (>= 0.0.9, < 0.2)
+    mime-types (3.2.2)
+      mime-types-data (~> 3.2015)
+    mime-types-data (3.2018.0812)
+    mini_portile2 (2.4.0)
     minitest (5.11.3)
+    net-http-digest_auth (1.4.1)
+    net-http-persistent (3.0.0)
+      connection_pool (~> 2.2)
+    nokogiri (1.10.1)
+      mini_portile2 (~> 2.4.0)
+    ntlm-http (0.1.1)
     parallel (1.13.0)
     parser (2.6.0.0)
       ast (~> 2.4.0)
@@ -34,7 +58,11 @@ GEM
     thread_safe (0.3.6)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
+    unf (0.1.4)
+      unf_ext
+    unf_ext (0.0.7.5)
     unicode-display_width (1.4.1)
+    webrobots (0.1.2)
 
 PLATFORMS
   ruby
@@ -43,6 +71,7 @@ DEPENDENCIES
   activesupport
   backports
   concurrent-ruby
+  mechanize
   plist
   rubocop
   rubocop-rspec
diff --git a/Library/Homebrew/vendor/bundle-standalone/bundler/setup.rb b/Library/Homebrew/vendor/bundle-standalone/bundler/setup.rb
index 15ec44a4a3..11e6185af5 100644
--- a/Library/Homebrew/vendor/bundle-standalone/bundler/setup.rb
+++ b/Library/Homebrew/vendor/bundle-standalone/bundler/setup.rb
@@ -12,8 +12,24 @@ $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/activesupport-5.2.2/l
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/ast-2.4.0/lib"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/backports-3.11.4/lib"
 $:.unshift "#{path}/"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/connection_pool-2.2.2/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/extensions/universal-darwin-18/2.3.0/unf_ext-0.0.7.5"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/unf_ext-0.0.7.5/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/unf-0.1.4/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/domain_name-0.5.20180417/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/http-cookie-1.0.3/lib"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/extensions/universal-darwin-18/2.3.0/jaro_winkler-1.5.2"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/jaro_winkler-1.5.2/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/mime-types-data-3.2018.0812/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/mime-types-3.2.2/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/net-http-digest_auth-1.4.1/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/net-http-persistent-3.0.0/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/mini_portile2-2.4.0/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/extensions/universal-darwin-18/2.3.0/nokogiri-1.10.1"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/nokogiri-1.10.1/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/ntlm-http-0.1.1/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/webrobots-0.1.2/lib"
+$:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/mechanize-2.7.6/lib"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/parallel-1.13.0/lib"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/parser-2.6.0.0/lib"
 $:.unshift "#{path}/../#{ruby_engine}/#{ruby_version}/gems/plist-3.5.0/lib"
diff --git a/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/http/content_disposition_parser.rb b/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/http/content_disposition_parser.rb
new file mode 100644
index 0000000000..e1ee752536
--- /dev/null
+++ b/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/http/content_disposition_parser.rb
@@ -0,0 +1,191 @@
+# coding: BINARY
+
+require 'strscan'
+require 'time'
+
+class Mechanize::HTTP
+  ContentDisposition = Struct.new :type, :filename, :creation_date,
+    :modification_date, :read_date, :size, :parameters
+end
+
+##
+# Parser Content-Disposition headers that loosely follows RFC 2183.
+#
+# Beyond RFC 2183, this parser allows:
+#
+# * Missing disposition-type
+# * Multiple semicolons
+# * Whitespace around semicolons
+
+class Mechanize::HTTP::ContentDispositionParser
+
+  attr_accessor :scanner # :nodoc:
+
+  @parser = nil
+
+  ##
+  # Parses the disposition type and params in the +content_disposition+
+  # string.  The "Content-Disposition:" must be removed.
+
+  def self.parse content_disposition
+    @parser ||= self.new
+    @parser.parse content_disposition
+  end
+
+  ##
+  # Creates a new parser Content-Disposition headers
+
+  def initialize
+    @scanner = nil
+  end
+
+  ##
+  # Parses the +content_disposition+ header.  If +header+ is set to true the
+  # "Content-Disposition:" portion will be parsed
+
+  def parse content_disposition, header = false
+    return nil if content_disposition.empty?
+
+    @scanner = StringScanner.new content_disposition
+
+    if header then
+      return nil unless @scanner.scan(/Content-Disposition/i)
+      return nil unless @scanner.scan(/:/)
+      spaces
+    end
+
+    type = rfc_2045_token
+    @scanner.scan(/;+/)
+
+    if @scanner.peek(1) == '=' then
+      @scanner.pos = 0
+      type = nil
+    end
+
+    disposition = Mechanize::HTTP::ContentDisposition.new type
+
+    spaces
+
+    return nil unless parameters = parse_parameters
+
+    disposition.filename          = parameters.delete 'filename'
+    disposition.creation_date     = parameters.delete 'creation-date'
+    disposition.modification_date = parameters.delete 'modification-date'
+    disposition.read_date         = parameters.delete 'read-date'
+    disposition.size              = parameters.delete 'size'
+    disposition.parameters        = parameters
+
+    disposition
+  end
+
+  ##
+  # Extracts disposition-parm and returns a Hash.
+
+  def parse_parameters
+    parameters = {}
+
+    while true do
+      return nil unless param = rfc_2045_token
+      param.downcase!
+      return nil unless @scanner.scan(/=/)
+
+      value = case param
+              when /^filename$/ then
+                rfc_2045_value
+              when /^(creation|modification|read)-date$/ then
+                Time.rfc822 rfc_2045_quoted_string
+              when /^size$/ then
+                rfc_2045_value.to_i(10)
+              else
+                rfc_2045_value
+              end
+
+      return nil unless value
+
+      parameters[param] = value
+
+      spaces
+
+      break if @scanner.eos? or not @scanner.scan(/;+/)
+
+      spaces
+    end
+
+    parameters
+  end
+
+  ##
+  #   quoted-string = <"> *(qtext/quoted-pair) <">
+  #   qtext         = <any CHAR excepting <">, "\" & CR,
+  #                    and including linear-white-space
+  #   quoted-pair   = "\" CHAR
+  #
+  # Parses an RFC 2045 quoted-string
+
+  def rfc_2045_quoted_string
+    return nil unless @scanner.scan(/"/)
+
+    text = ''
+
+    while true do
+      chunk = @scanner.scan(/[\000-\014\016-\041\043-\133\135-\177]+/) # not \r "
+
+      if chunk then
+        text << chunk
+
+        if @scanner.peek(1) == '\\' then
+          @scanner.get_byte
+          return nil if @scanner.eos?
+          text << @scanner.get_byte
+        elsif @scanner.scan(/\r\n[\t ]+/) then
+          text << " "
+        end
+      else
+        if '\\"' == @scanner.peek(2) then
+          @scanner.skip(/\\/)
+          text << @scanner.get_byte
+        elsif '"' == @scanner.peek(1) then
+          @scanner.get_byte
+          break
+        else
+          return nil
+        end
+      end
+    end
+
+    text
+  end
+
+  ##
+  #   token := 1*<any (US-ASCII) CHAR except SPACE, CTLs, or tspecials>
+  #
+  # Parses an RFC 2045 token
+
+  def rfc_2045_token
+    @scanner.scan(/[^\000-\037\177()<>@,;:\\"\/\[\]?= ]+/)
+  end
+
+  ##
+  #   value := token / quoted-string
+  #
+  # Parses an RFC 2045 value
+
+  def rfc_2045_value
+    if @scanner.peek(1) == '"' then
+      rfc_2045_quoted_string
+    else
+      rfc_2045_token
+    end
+  end
+
+  ##
+  #   1*SP
+  #
+  # Parses spaces
+
+  def spaces
+    @scanner.scan(/ +/)
+  end
+
+end
+
diff --git a/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/version.rb b/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/version.rb
new file mode 100644
index 0000000000..89dbfaf8a6
--- /dev/null
+++ b/Library/Homebrew/vendor/bundle-standalone/ruby/2.3.0/gems/mechanize-2.7.6/lib/mechanize/version.rb
@@ -0,0 +1,3 @@
+class Mechanize
+  VERSION = "2.7.6"
+end