Merge commit 'mainstream/master'

Conflicts:
	actionpack/lib/action_view/helpers/text_helper.rb
	activesupport/lib/active_support/inflector.rb

20 files changed, 139 insertions, 63 deletions

diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index ca826e7bfc..d03f4cb231 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -31,7 +31,12 @@ rescue LoadError
   end
 end
 
-require 'action_controller/vendor/rack-1.0/rack'
+begin
+  gem 'rack', '~> 1.0.0'
+  require 'rack'
+rescue Gem::LoadError
+  require 'action_controller/vendor/rack-1.0/rack'
+end
 
 module ActionController
   # TODO: Review explicit to see if they will automatically be handled by
diff --git a/actionpack/lib/action_controller/caching/actions.rb b/actionpack/lib/action_controller/caching/actions.rb
index 34e1c3527f..87b5029e57 100644
--- a/actionpack/lib/action_controller/caching/actions.rb
+++ b/actionpack/lib/action_controller/caching/actions.rb
@@ -129,24 +129,23 @@ module ActionController #:nodoc:
         attr_reader :path, :extension
 
         class << self
-          def path_for(controller, options, infer_extension=true)
+          def path_for(controller, options, infer_extension = true)
             new(controller, options, infer_extension).path
           end
         end
         
         # When true, infer_extension will look up the cache path extension from the request's path & format.
-        # This is desirable when reading and writing the cache, but not when expiring the cache -  expire_action should expire the same files regardless of the request format.
-        def initialize(controller, options = {}, infer_extension=true)
-          if infer_extension and options.is_a? Hash
-            request_extension = extract_extension(controller.request)
-            options = options.reverse_merge(:format => request_extension)
+        # This is desirable when reading and writing the cache, but not when expiring the cache -
+        # expire_action should expire the same files regardless of the request format.
+        def initialize(controller, options = {}, infer_extension = true)
+          if infer_extension
+            extract_extension(controller.request)
+            options = options.reverse_merge(:format => @extension) if options.is_a?(Hash)
           end
+
           path = controller.url_for(options).split('://').last
           normalize!(path)
-          if infer_extension
-            @extension = request_extension
-            add_extension!(path, @extension)
-          end
+          add_extension!(path, @extension)
           @path = URI.unescape(path)
         end
 
@@ -162,13 +161,7 @@ module ActionController #:nodoc:
           def extract_extension(request)
             # Don't want just what comes after the last '.' to accommodate multi part extensions
             # such as tar.gz.
-            extension = request.path[/^[^.]+\.(.+)$/, 1]
-
-            # If there's no extension in the path, check request.format
-            if extension.nil?
-              extension = request.cache_format
-            end
-            extension
+            @extension = request.path[/^[^.]+\.(.+)$/, 1] || request.cache_format
           end
       end
     end
diff --git a/actionpack/lib/action_controller/http_authentication.rb b/actionpack/lib/action_controller/http_authentication.rb
index 2ccbc22420..b6b5267c66 100644
--- a/actionpack/lib/action_controller/http_authentication.rb
+++ b/actionpack/lib/action_controller/http_authentication.rb
@@ -68,8 +68,11 @@ module ActionController
     #
     # Simple Digest example:
     #
+    #   require 'digest/md5'
     #   class PostsController < ApplicationController
-    #     USERS = {"dhh" => "secret"}
+    #     REALM = "SuperSecret"
+    #     USERS = {"dhh" => "secret", #plain text password
+    #              "dap" => Digest:MD5::hexdigest(["dap",REALM,"secret"].join(":"))  #ha1 digest password
     #
     #     before_filter :authenticate, :except => [:index]
     #
@@ -83,14 +86,18 @@ module ActionController
     #
     #     private
     #       def authenticate
-    #         authenticate_or_request_with_http_digest(realm) do |username|
+    #         authenticate_or_request_with_http_digest(REALM) do |username|
     #           USERS[username]
     #         end
     #       end
     #   end
     #
-    # NOTE: The +authenticate_or_request_with_http_digest+ block must return the user's password so the framework can appropriately
-    #       hash it to check the user's credentials. Returning +nil+ will cause authentication to fail.
+    # NOTE: The +authenticate_or_request_with_http_digest+ block must return the user's password or the ha1 digest hash so the framework can appropriately
+    #       hash to check the user's credentials. Returning +nil+ will cause authentication to fail.
+    #       Storing the ha1 hash: MD5(username:realm:password), is better than storing a plain password. If
+    #       the password file or database is compromised, the attacker would be able to use the ha1 hash to
+    #       authenticate as the user at this +realm+, but would not have the user's password to try using at
+    #       other sites.
     #
     # On shared hosts, Apache sometimes doesn't pass authentication headers to
     # FCGI instances. If your environment matches this description and you cannot
@@ -177,26 +184,37 @@ module ActionController
       end
 
       # Raises error unless the request credentials response value matches the expected value.
+      # First try the password as a ha1 digest password. If this fails, then try it as a plain
+      # text password.
       def validate_digest_response(request, realm, &password_procedure)
         credentials = decode_credentials_header(request)
         valid_nonce = validate_nonce(request, credentials[:nonce])
 
-        if valid_nonce && realm == credentials[:realm] && opaque(request.session.session_id) == credentials[:opaque]
+        if valid_nonce && realm == credentials[:realm] && opaque == credentials[:opaque]
           password = password_procedure.call(credentials[:username])
-          expected = expected_response(request.env['REQUEST_METHOD'], credentials[:uri], credentials, password)
-          expected == credentials[:response]
+
+         [true, false].any? do |password_is_ha1|
+           expected = expected_response(request.env['REQUEST_METHOD'], request.env['REQUEST_URI'], credentials, password, password_is_ha1)
+           expected == credentials[:response]
+         end
         end
       end
 
       # Returns the expected response for a request of +http_method+ to +uri+ with the decoded +credentials+ and the expected +password+
-      def expected_response(http_method, uri, credentials, password)
-        ha1 = ::Digest::MD5.hexdigest([credentials[:username], credentials[:realm], password].join(':'))
+      # Optional parameter +password_is_ha1+ is set to +true+ by default, since best practice is to store ha1 digest instead
+      # of a plain-text password.
+      def expected_response(http_method, uri, credentials, password, password_is_ha1=true)
+        ha1 = password_is_ha1 ? password : ha1(credentials, password)
         ha2 = ::Digest::MD5.hexdigest([http_method.to_s.upcase, uri].join(':'))
         ::Digest::MD5.hexdigest([ha1, credentials[:nonce], credentials[:nc], credentials[:cnonce], credentials[:qop], ha2].join(':'))
       end
 
-      def encode_credentials(http_method, credentials, password)
-        credentials[:response] = expected_response(http_method, credentials[:uri], credentials, password)
+      def ha1(credentials, password)
+        ::Digest::MD5.hexdigest([credentials[:username], credentials[:realm], password].join(':'))
+      end
+
+      def encode_credentials(http_method, credentials, password, password_is_ha1)
+        credentials[:response] = expected_response(http_method, credentials[:uri], credentials, password, password_is_ha1)
         "Digest " + credentials.sort_by {|x| x[0].to_s }.inject([]) {|a, v| a << "#{v[0]}='#{v[1]}'" }.join(', ')
       end
 
@@ -213,8 +231,7 @@ module ActionController
       end
 
       def authentication_header(controller, realm)
-        session_id = controller.request.session.session_id
-        controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce(session_id)}", opaque="#{opaque(session_id)}")
+        controller.headers["WWW-Authenticate"] = %(Digest realm="#{realm}", qop="auth", algorithm=MD5, nonce="#{nonce}", opaque="#{opaque}")
       end
 
       def authentication_request(controller, realm, message = nil)
@@ -252,23 +269,36 @@ module ActionController
       # POST or PUT requests and a time-stamp for GET requests. For more details on the issues involved see Section 4
       # of this document.
       #
-      # The nonce is opaque to the client.
-      def nonce(session_id, time = Time.now)
+      # The nonce is opaque to the client. Composed of Time, and hash of Time with secret
+      # key from the Rails session secret generated upon creation of project. Ensures
+      # the time cannot be modifed by client.
+      def nonce(time = Time.now)
         t = time.to_i
-        hashed = [t, session_id]
+        hashed = [t, secret_key]
         digest = ::Digest::MD5.hexdigest(hashed.join(":"))
         Base64.encode64("#{t}:#{digest}").gsub("\n", '')
       end
 
-      def validate_nonce(request, value)
+      # Might want a shorter timeout depending on whether the request
+      # is a PUT or POST, and if client is browser or web service.
+      # Can be much shorter if the Stale directive is implemented. This would
+      # allow a user to use new nonce without prompting user again for their
+      # username and password.
+      def validate_nonce(request, value, seconds_to_timeout=5*60)
         t = Base64.decode64(value).split(":").first.to_i
-        nonce(request.session.session_id, t) == value && (t - Time.now.to_i).abs <= 10 * 60
+        nonce(t) == value && (t - Time.now.to_i).abs <= seconds_to_timeout
       end
 
-      # Opaque based on digest of session_id
-      def opaque(session_id)
-        Base64.encode64(::Digest::MD5::hexdigest(session_id)).gsub("\n", '')
+      # Opaque based on random generation - but changing each request?
+      def opaque()
+        ::Digest::MD5.hexdigest(secret_key)
       end
+
+      # Set in /initializers/session_store.rb, and loaded even if sessions are not in use.
+      def secret_key
+        ActionController::Base.session_options[:secret]
+      end
+
     end
   end
 end
diff --git a/actionpack/lib/action_controller/request.rb b/actionpack/lib/action_controller/request.rb
index 2cabab9ec8..ef223f157c 100755
--- a/actionpack/lib/action_controller/request.rb
+++ b/actionpack/lib/action_controller/request.rb
@@ -442,6 +442,7 @@ EOM
     end
 
     def reset_session
+      @env['rack.session.options'].delete(:id)
       @env['rack.session'] = {}
     end
 
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack.rb
index 6c03b55552..e3e20ed2a3 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack.rb
@@ -31,6 +31,7 @@ module Rack
   autoload :CommonLogger, "rack/commonlogger"
   autoload :ConditionalGet, "rack/conditionalget"
   autoload :ContentLength, "rack/content_length"
+  autoload :ContentType, "rack/content_type"
   autoload :File, "rack/file"
   autoload :Deflater, "rack/deflater"
   autoload :Directory, "rack/directory"
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/abstract/handler.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/abstract/handler.rb
index 8489c9b9c4..214df6299e 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/abstract/handler.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/abstract/handler.rb
@@ -8,8 +8,8 @@ module Rack
 
       attr_accessor :realm
 
-      def initialize(app, &authenticator)
-        @app, @authenticator = app, authenticator
+      def initialize(app, realm=nil, &authenticator)
+        @app, @realm, @authenticator = app, realm, authenticator
       end
 
 
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/md5.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/md5.rb
index 6d2bd29c2e..e579dc9632 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/md5.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/md5.rb
@@ -21,7 +21,7 @@ module Rack
 
         attr_writer :passwords_hashed
 
-        def initialize(app)
+        def initialize(*args)
           super
           @passwords_hashed = nil
         end
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/request.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/request.rb
index a40f57b7f1..a8aa3bf996 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/request.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/auth/digest/request.rb
@@ -8,7 +8,7 @@ module Rack
       class Request < Auth::AbstractRequest
 
         def method
-          @env['REQUEST_METHOD']
+          @env['rack.methodoverride.original_method'] || @env['REQUEST_METHOD']
         end
 
         def digest?
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/builder.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/builder.rb
index 25994d5a44..295235e56a 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/builder.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/builder.rb
@@ -34,11 +34,7 @@ module Rack
     end
 
     def use(middleware, *args, &block)
-      @ins << if block_given?
-        lambda { |app| middleware.new(app, *args, &block) }
-      else
-        lambda { |app| middleware.new(app, *args) }
-      end
+      @ins << lambda { |app| middleware.new(app, *args, &block) }
     end
 
     def run(app)
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_length.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_length.rb
index bce22a32c5..1e56d43853 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_length.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_length.rb
@@ -3,21 +3,23 @@ require 'rack/utils'
 module Rack
   # Sets the Content-Length header on responses with fixed-length bodies.
   class ContentLength
+    include Rack::Utils
+
     def initialize(app)
       @app = app
     end
 
     def call(env)
       status, headers, body = @app.call(env)
-      headers = Utils::HeaderHash.new(headers)
+      headers = HeaderHash.new(headers)
 
-      if !Utils::STATUS_WITH_NO_ENTITY_BODY.include?(status) &&
+      if !STATUS_WITH_NO_ENTITY_BODY.include?(status) &&
          !headers['Content-Length'] &&
          !headers['Transfer-Encoding'] &&
          (body.respond_to?(:to_ary) || body.respond_to?(:to_str))
 
         body = [body] if body.respond_to?(:to_str) # rack 0.4 compat
-        length = body.to_ary.inject(0) { |len, part| len + part.length }
+        length = body.to_ary.inject(0) { |len, part| len + bytesize(part) }
         headers['Content-Length'] = length.to_s
       end
 
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_type.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_type.rb
new file mode 100644
index 0000000000..0c1e1ca3e1
--- /dev/null
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/content_type.rb
@@ -0,0 +1,23 @@
+require 'rack/utils'
+
+module Rack
+
+  # Sets the Content-Type header on responses which don't have one.
+  #
+  # Builder Usage:
+  #   use Rack::ContentType, "text/plain"
+  #
+  # When no content type argument is provided, "text/html" is assumed.
+  class ContentType
+    def initialize(app, content_type = "text/html")
+      @app, @content_type = app, content_type
+    end
+
+    def call(env)
+      status, headers, body = @app.call(env)
+      headers = Utils::HeaderHash.new(headers)
+      headers['Content-Type'] ||= @content_type
+      [status, headers.to_hash, body]
+    end
+  end
+end
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/deflater.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/deflater.rb
index 3e66680092..a42b7477ae 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/deflater.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/deflater.rb
@@ -36,12 +36,12 @@ module Rack
         mtime = headers.key?("Last-Modified") ?
           Time.httpdate(headers["Last-Modified"]) : Time.now
         body = self.class.gzip(body, mtime)
-        size = body.respond_to?(:bytesize) ? body.bytesize : body.size
+        size = Rack::Utils.bytesize(body)
         headers = headers.merge("Content-Encoding" => "gzip", "Content-Length" => size.to_s)
         [status, headers, [body]]
       when "deflate"
         body = self.class.deflate(body)
-        size = body.respond_to?(:bytesize) ? body.bytesize : body.size
+        size = Rack::Utils.bytesize(body)
         headers = headers.merge("Content-Encoding" => "deflate", "Content-Length" => size.to_s)
         [status, headers, [body]]
       when "identity"
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/directory.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/directory.rb
index 56ee5e7b60..acdd3029d3 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/directory.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/directory.rb
@@ -70,7 +70,7 @@ table { width:100%%; }
       return unless @path_info.include? ".."
 
       body = "Forbidden\n"
-      size = body.respond_to?(:bytesize) ? body.bytesize : body.size
+      size = Rack::Utils.bytesize(body)
       return [403, {"Content-Type" => "text/plain","Content-Length" => size.to_s}, [body]]
     end
 
@@ -89,6 +89,8 @@ table { width:100%%; }
         type = stat.directory? ? 'directory' : Mime.mime_type(ext)
         size = stat.directory? ? '-' : filesize_format(size)
         mtime = stat.mtime.httpdate
+        url << '/'  if stat.directory?
+        basename << '/'  if stat.directory?
 
         @files << [ url, basename, size, type, mtime ]
       end
@@ -120,7 +122,7 @@ table { width:100%%; }
 
     def entity_not_found
       body = "Entity not found: #{@path_info}\n"
-      size = body.respond_to?(:bytesize) ? body.bytesize : body.size
+      size = Rack::Utils.bytesize(body)
       return [404, {"Content-Type" => "text/plain", "Content-Length" => size.to_s}, [body]]
     end
 
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/lsws.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/lsws.rb
index 1f850fc77b..dfc79c204b 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/lsws.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/lsws.rb
@@ -13,7 +13,7 @@ module Rack
         env.delete "HTTP_CONTENT_LENGTH"
         env["SCRIPT_NAME"] = "" if env["SCRIPT_NAME"] == "/"
         env.update({"rack.version" => [0,1],
-                     "rack.input" => $stdin,
+                     "rack.input" => StringIO.new($stdin.read.to_s),
                      "rack.errors" => $stderr,
                      "rack.multithread" => false,
                      "rack.multiprocess" => true,
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/webrick.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/webrick.rb
index 40be79de13..138aae0ee9 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/webrick.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/handler/webrick.rb
@@ -35,7 +35,12 @@ module Rack
         env["HTTP_VERSION"] ||= env["SERVER_PROTOCOL"]
         env["QUERY_STRING"] ||= ""
         env["REQUEST_PATH"] ||= "/"
-        env.delete "PATH_INFO"  if env["PATH_INFO"] == ""
+        if env["PATH_INFO"] == ""
+          env.delete "PATH_INFO"
+        else
+          path, n = req.request_uri.path, env["SCRIPT_NAME"].length
+          env["PATH_INFO"] = path[n, path.length-n]
+        end
 
         status, headers, body = @app.call(env)
         begin
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/lint.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/lint.rb
index 7eb05437f0..ec4dac96f8 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/lint.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/lint.rb
@@ -88,7 +88,9 @@ module Rack
       ##                      within the application. This may be an
       ##                      empty string, if the request URL targets
       ##                      the application root and does not have a
-      ##                      trailing slash.
+      ##                      trailing slash. This information should be
+      ##                      decoded by the server if it comes from a
+      ##                      URL.
 
       ## <tt>QUERY_STRING</tt>:: The portion of the request URL that
       ##                         follows the <tt>?</tt>, if any. May be
@@ -401,7 +403,7 @@ module Rack
               break
             end
 
-            bytes += (part.respond_to?(:bytesize) ? part.bytesize : part.size)
+            bytes += Rack::Utils.bytesize(part)
           }
 
           if env["REQUEST_METHOD"] == "HEAD"
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/response.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/response.rb
index a593110139..caf60d5b19 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/response.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/response.rb
@@ -16,6 +16,8 @@ module Rack
   # Your application's +call+ should end returning Response#finish.
 
   class Response
+    attr_accessor :length
+
     def initialize(body=[], status=200, header={}, &block)
       @status = status
       @header = Utils::HeaderHash.new({"Content-Type" => "text/html"}.
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/showstatus.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/showstatus.rb
index 5f13404dce..28258c7c89 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/showstatus.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/showstatus.rb
@@ -27,7 +27,7 @@ module Rack
         message = Rack::Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s
         detail = env["rack.showstatus.detail"] || message
         body = @template.result(binding)
-        size = body.respond_to?(:bytesize) ? body.bytesize : body.size
+        size = Rack::Utils.bytesize(body)
         [status, headers.merge("Content-Type" => "text/html", "Content-Length" => size.to_s), [body]]
       else
         [status, headers, body]
diff --git a/actionpack/lib/action_controller/vendor/rack-1.0/rack/utils.rb b/actionpack/lib/action_controller/vendor/rack-1.0/rack/utils.rb
index f352cb6783..e86d4ccdcd 100644
--- a/actionpack/lib/action_controller/vendor/rack-1.0/rack/utils.rb
+++ b/actionpack/lib/action_controller/vendor/rack-1.0/rack/utils.rb
@@ -144,6 +144,19 @@ module Rack
     end
     module_function :select_best_encoding
 
+    # Return the bytesize of String; uses String#length under Ruby 1.8 and
+    # String#bytesize under 1.9.
+    if ''.respond_to?(:bytesize)
+      def bytesize(string)
+        string.bytesize
+      end
+    else
+      def bytesize(string)
+        string.size
+      end
+    end
+    module_function :bytesize
+
     # Context allows the use of a compatible middleware at different points
     # in a request handling stack. A compatible middleware must define
     # #context which should take the arguments env and app. The first of which
diff --git a/actionpack/lib/action_view/helpers/text_helper.rb b/actionpack/lib/action_view/helpers/text_helper.rb
index feeddba78d..48bf4717ad 100644
--- a/actionpack/lib/action_view/helpers/text_helper.rb
+++ b/actionpack/lib/action_view/helpers/text_helper.rb
@@ -536,9 +536,10 @@ module ActionView
           text.gsub(AUTO_LINK_RE) do
             href = $&
             punctuation = ''
-            # detect already linked URLs
-            if $` =~ /<a\s[^>]*href="$/
-              # do not change string; URL is already linked
+            left, right = $`, $'
+            # detect already linked URLs and URLs in the middle of a tag
+            if left =~ /<[^>]+$/ && right =~ /^[^>]*>/
+              # do not change string; URL is alreay linked
               href
             else
               # don't include trailing punctuation character as part of the URL