Bringing Accept header parsing in line with the spec.

For reference:
  http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
  http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2

lib/sinatra/base.rb

@@ -16,12 +16,16 @@ module Sinatra
   # The request object. See Rack::Request for more info:
   # http://rack.rubyforge.org/doc/classes/Rack/Request.html
   class Request < Rack::Request
+    HEADER_PARAM = /;[\d\w.]+=(?:[\d\w.]+|"(?:[^"\\]|\\.)*")?/
+    HEADER_VALUE_WITH_PARAMS = /(?:(?:\w+|\*)\/(?:\w+|\*))(?:#{HEADER_PARAM})*/
+
     # Returns an array of acceptable media types for the response
     def accept
-      @env['sinatra.accept'] ||= begin
-        entries = @env['HTTP_ACCEPT'].to_s.split(',')
-        entries.map { |e| accept_entry(e) }.sort_by(&:last).map(&:first)
+      @env['sinatra.accept_entries'] ||= begin
+        entries = @env['HTTP_ACCEPT'].to_s.scan(HEADER_VALUE_WITH_PARAMS)
+        entries.map { |e| accept_entry(e) }.sort_by(&:last)
       end
+      @env['sinatra.accept'] ||= @env['sinatra.accept_entries'].map(&:first)
     end
 
     def preferred_type(*types)
@@ -51,10 +55,11 @@ module Sinatra
     private
 
     def accept_entry(entry)
-      type, *options = entry.delete(' ').split(';')
+      type = entry.delete(' ').split(';').first
+      options = entry.scan(HEADER_PARAM).map { |s| s[1..-1] }
       quality = 0 # we sort smallest first
       options.delete_if { |e| quality = 1 - e[2..-1].to_f if e.start_with? 'q=' }
-      [type, [quality, type.count('*'), 1 - options.size]]
+      [type, options, [quality, type.count('*'), 1 - options.size]]
     end
   end
 

test/filter_test.rb

@@ -431,7 +431,7 @@ class AfterFilterTest < Test::Unit::TestCase
       get('/') { @type }
     end
 
-    get('/', {}, { 'HTTP_ACCEPT' => '*' })
+    get('/', {}, { 'HTTP_ACCEPT' => '*/*' })
     assert_body 'txt'
   end
 end

test/routing_test.rb

@@ -779,7 +779,7 @@ class RoutingTest < Test::Unit::TestCase
       get('*', :provides => :html) { 'html' }
     end
 
-    get '/', {}, { 'HTTP_ACCEPT' => '*' }
+    get '/', {}, { 'HTTP_ACCEPT' => '*/*' }
     assert ok?
     assert_equal 'text/plain;charset=utf-8', response.headers['Content-Type']
     assert_body 'txt'
@@ -826,7 +826,7 @@ class RoutingTest < Test::Unit::TestCase
     assert_equal 'default', body
   end
 
-  it 'respects user agent prefferences for the content type' do
+  it 'respects user agent preferences for the content type' do
     mock_app { get('/', :provides => [:png, :html]) { content_type }}
     get '/', {}, { 'HTTP_ACCEPT' => 'image/png;q=0.5,text/html;q=0.8' }
     assert_body 'text/html;charset=utf-8'
@@ -881,6 +881,55 @@ class RoutingTest < Test::Unit::TestCase
     assert_body 'text/html;charset=utf-8'
   end
 
+  it 'supplies a default quality of 1.0' do
+    mock_app { get('/', :provides => [:png, :html]) { content_type }}
+    get '/', {}, { 'HTTP_ACCEPT' => 'image/png;q=0.5, text/*' }
+    assert_body 'text/html;charset=utf-8'
+  end
+
+  it 'orders types with equal quality by parameter count' do
+    mock_app do
+      get('/', :provides => [:png, :jpg]) { content_type }
+    end
+
+    lo_png = 'image/png;q=0.5'
+    hi_png = 'image/png;q=0.5;profile=FOGRA40;gamma=0.8'
+    jpeg   = 'image/jpeg;q=0.5;compress=0.25'
+
+    get '/', {}, { 'HTTP_ACCEPT' => "#{lo_png}, #{jpeg}" }
+    assert_body 'image/jpeg'
+    get '/', {}, { 'HTTP_ACCEPT' => "#{hi_png}, #{jpeg}" }
+    assert_body 'image/png'
+  end
+
+  it 'ignores the quality parameter when ordering by parameter count' do
+    mock_app do
+      get('/', :provides => [:png, :jpg]) { content_type }
+    end
+
+    lo_png = 'image/png'
+    hi_png = 'image/png;profile=FOGRA40;gamma=0.8'
+    jpeg   = 'image/jpeg;q=1.0;compress=0.25'
+
+    get '/', {}, { 'HTTP_ACCEPT' => "#{jpeg}, #{lo_png}" }
+    assert_body 'image/jpeg'
+    get '/', {}, { 'HTTP_ACCEPT' => "#{jpeg}, #{hi_png}" }
+    assert_body 'image/png'
+  end
+
+  it 'properly handles quoted strings in parameters' do
+    mock_app do
+      get('/', :provides => [:png, :jpg]) { content_type }
+    end
+
+    get '/', {}, { 'HTTP_ACCEPT' => 'image/png;q=0.5;profile=",image/jpeg,"' }
+    assert_body 'image/png'
+    get '/', {}, { 'HTTP_ACCEPT' => 'image/png;q=0.5,image/jpeg;q=0;x=";q=1.0"' }
+    assert_body 'image/png'
+    get '/', {}, { 'HTTP_ACCEPT' => 'image/png;q=0.5,image/jpeg;q=0;x="\";q=1.0"' }
+    assert_body 'image/png'
+  end
+
   it 'accepts both text/javascript and application/javascript for js' do
     mock_app { get('/', :provides => :js) { content_type }}
     get '/', {}, { 'HTTP_ACCEPT' => 'application/javascript' }