Handle invalid quality values. Close fnando#315.

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## UNRELEASED
 
 - Add Google Site Verification to the bot list.
+- Handle invalid quality values that look like numbers.
 
 ## v2.5.2
 

lib/browser/accept_language.rb

@@ -47,14 +47,20 @@ def region
     end
 
     def quality
-      @quality ||= Float(quality_value || 1.0)
+      @quality ||= begin
+        Float(quality_value || 1.0)
+      rescue ArgumentError
+        0.1
+      end
     end
 
     private
 
     def quality_value
       qvalue = part[/;q=([\d.]+)/, 1]
-      qvalue =~ /\A0\.0?\z/ ? "0.0" : qvalue
+      qvalue = qvalue =~ /\A0\.0?\z/ ? "0.0" : qvalue
+      qvalue = qvalue.gsub(/\.+/, ".") if qvalue
+      qvalue
     end
   end
 end

test/unit/accept_language_test.rb

@@ -139,4 +139,12 @@ def assert_language(item, expect = {})
     assert_language result[1], code: "ru", region: nil, quality: 0.9
     assert_language result[2], code: "de", region: nil, quality: 0.8
   end
+
+  test "handles invalid quality values that look like a number" do
+    accept_language = "fr-CH, fr;q=0.9, en;q=0.8, de;q=0..7, *;q=0.5"
+    result = Browser::AcceptLanguage.parse(accept_language)
+
+    assert_equal 5, result.size
+    assert_language result[3], code: "de", region: nil, quality: 0.7
+  end
 end