1 files changed, 56 insertions, 44 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/static.rb b/actionpack/lib/action_dispatch/middleware/static.rb
index fdd1bc4e69..23492e14eb 100644
--- a/actionpack/lib/action_dispatch/middleware/static.rb
+++ b/actionpack/lib/action_dispatch/middleware/static.rb
@@ -1,34 +1,41 @@
-require 'rack/utils'
-require 'active_support/core_ext/uri'
+# frozen_string_literal: true
+
+require "rack/utils"
+require "active_support/core_ext/uri"
 
 module ActionDispatch
   # This middleware returns a file's contents from disk in the body response.
-  # When initialized it can accept an optional 'Cache-Control' header which
-  # will be set when a response containing a file's contents is delivered.
+  # When initialized, it can accept optional HTTP headers, which will be set
+  # when a response containing a file's contents is delivered.
   #
-  # This middleware will render the file specified in `env["PATH_INFO"]`
-  # where the base path is in the +root+ directory. For example if the +root+
-  # is set to `public/` then a request with `env["PATH_INFO"]` of
-  # `assets/application.js` will return a response with contents of a file
-  # located at `public/assets/application.js` if the file exists. If the file
-  # does not exist a 404 "File not Found" response will be returned.
+  # This middleware will render the file specified in <tt>env["PATH_INFO"]</tt>
+  # where the base path is in the +root+ directory. For example, if the +root+
+  # is set to +public/+, then a request with <tt>env["PATH_INFO"]</tt> of
+  # +assets/application.js+ will return a response with the contents of a file
+  # located at +public/assets/application.js+ if the file exists. If the file
+  # does not exist, a 404 "File not Found" response will be returned.
   class FileHandler
-    def initialize(root, cache_control)
-      @root          = root.chomp('/')
-      @compiled_root = /^#{Regexp.escape(root)}/
-      headers        = cache_control && { 'Cache-Control' => cache_control }
-      @file_server = ::Rack::File.new(@root, headers)
+    def initialize(root, index: "index", headers: {})
+      @root          = root.chomp("/")
+      @file_server   = ::Rack::File.new(@root, headers)
+      @index         = index
     end
 
+    # Takes a path to a file. If the file is found, has valid encoding, and has
+    # correct read permissions, the return value is a URI-escaped string
+    # representing the filename. Otherwise, false is returned.
+    #
+    # Used by the +Static+ class to check the existence of a valid file
+    # in the server's +public/+ directory (see Static#call).
     def match?(path)
-      path = URI.parser.unescape(path)
-      return false unless path.valid_encoding?
-      path = Rack::Utils.clean_path_info path
+      path = ::Rack::Utils.unescape_path path
+      return false unless ::Rack::Utils.valid_path? path
+      path = ::Rack::Utils.clean_path_info path
 
-      paths = [path, "#{path}#{ext}", "#{path}/index#{ext}"]
+      paths = [path, "#{path}#{ext}", "#{path}/#{@index}#{ext}"]
 
       if match = paths.detect { |p|
-        path = File.join(@root, p)
+        path = File.join(@root, p.dup.force_encoding(Encoding::UTF_8))
         begin
           File.file?(path) && File.readable?(path)
         rescue SystemCallError
@@ -36,31 +43,35 @@ module ActionDispatch
         end
 
       }
-        return ::Rack::Utils.escape(match)
+        return ::Rack::Utils.escape_path(match)
       end
     end
 
     def call(env)
-      path      = env['PATH_INFO']
+      serve(Rack::Request.new(env))
+    end
+
+    def serve(request)
+      path      = request.path_info
       gzip_path = gzip_file_path(path)
 
-      if gzip_path && gzip_encoding_accepted?(env)
-        env['PATH_INFO']            = gzip_path
-        status, headers, body       = @file_server.call(env)
+      if gzip_path && gzip_encoding_accepted?(request)
+        request.path_info           = gzip_path
+        status, headers, body       = @file_server.call(request.env)
         if status == 304
           return [status, headers, body]
         end
-        headers['Content-Encoding'] = 'gzip'
-        headers['Content-Type']     = content_type(path)
+        headers["Content-Encoding"] = "gzip"
+        headers["Content-Type"]     = content_type(path)
       else
-        status, headers, body = @file_server.call(env)
+        status, headers, body = @file_server.call(request.env)
       end
 
-      headers['Vary'] = 'Accept-Encoding' if gzip_path
+      headers["Vary"] = "Accept-Encoding" if gzip_path
 
       return [status, headers, body]
     ensure
-      env['PATH_INFO'] = path
+      request.path_info = path
     end
 
     private
@@ -69,17 +80,17 @@ module ActionDispatch
       end
 
       def content_type(path)
-        ::Rack::Mime.mime_type(::File.extname(path), 'text/plain')
+        ::Rack::Mime.mime_type(::File.extname(path), "text/plain".freeze)
       end
 
-      def gzip_encoding_accepted?(env)
-        env['HTTP_ACCEPT_ENCODING'] =~ /\bgzip\b/i
+      def gzip_encoding_accepted?(request)
+        request.accept_encoding.any? { |enc, quality| enc =~ /\bgzip\b/i }
       end
 
       def gzip_file_path(path)
         can_gzip_mime = content_type(path) =~ /\A(?:text\/|application\/javascript)/
         gzip_path     = "#{path}.gz"
-        if can_gzip_mime && File.exist?(File.join(@root, ::Rack::Utils.unescape(gzip_path)))
+        if can_gzip_mime && File.exist?(File.join(@root, ::Rack::Utils.unescape_path(gzip_path)))
           gzip_path
         else
           false
@@ -88,31 +99,32 @@ module ActionDispatch
   end
 
   # This middleware will attempt to return the contents of a file's body from
-  # disk in the response.  If a file is not found on disk, the request will be
+  # disk in the response. If a file is not found on disk, the request will be
   # delegated to the application stack. This middleware is commonly initialized
-  # to serve assets from a server's `public/` directory.
+  # to serve assets from a server's +public/+ directory.
   #
   # This middleware verifies the path to ensure that only files
   # living in the root directory can be rendered. A request cannot
   # produce a directory traversal using this middleware. Only 'GET' and 'HEAD'
   # requests will result in a file being returned.
   class Static
-    def initialize(app, path, cache_control=nil)
+    def initialize(app, path, index: "index", headers: {})
       @app = app
-      @file_handler = FileHandler.new(path, cache_control)
+      @file_handler = FileHandler.new(path, index: index, headers: headers)
     end
 
     def call(env)
-      case env['REQUEST_METHOD']
-      when 'GET', 'HEAD'
-        path = env['PATH_INFO'].chomp('/')
+      req = Rack::Request.new env
+
+      if req.get? || req.head?
+        path = req.path_info.chomp("/".freeze)
         if match = @file_handler.match?(path)
-          env["PATH_INFO"] = match
-          return @file_handler.call(env)
+          req.path_info = match
+          return @file_handler.serve(req)
         end
       end
 
-      @app.call(env)
+      @app.call(req.env)
     end
   end
 end