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Diffstat (limited to 'lib/gitlab/encoding_helper.rb')
-rw-r--r-- | lib/gitlab/encoding_helper.rb | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/lib/gitlab/encoding_helper.rb b/lib/gitlab/encoding_helper.rb new file mode 100644 index 00000000000..8ddc91e341d --- /dev/null +++ b/lib/gitlab/encoding_helper.rb @@ -0,0 +1,62 @@ +module Gitlab + module EncodingHelper + extend self + + # This threshold is carefully tweaked to prevent usage of encodings detected + # by CharlockHolmes with low confidence. If CharlockHolmes confidence is low, + # we're better off sticking with utf8 encoding. + # Reason: git diff can return strings with invalid utf8 byte sequences if it + # truncates a diff in the middle of a multibyte character. In this case + # CharlockHolmes will try to guess the encoding and will likely suggest an + # obscure encoding with low confidence. + # There is a lot more info with this merge request: + # https://gitlab.com/gitlab-org/gitlab_git/merge_requests/77#note_4754193 + ENCODING_CONFIDENCE_THRESHOLD = 50 + + def encode!(message) + return nil unless message.respond_to? :force_encoding + + # if message is utf-8 encoding, just return it + message.force_encoding("UTF-8") + return message if message.valid_encoding? + + # return message if message type is binary + detect = CharlockHolmes::EncodingDetector.detect(message) + return message.force_encoding("BINARY") if detect && detect[:type] == :binary + + # force detected encoding if we have sufficient confidence. + if detect && detect[:encoding] && detect[:confidence] > ENCODING_CONFIDENCE_THRESHOLD + message.force_encoding(detect[:encoding]) + end + + # encode and clean the bad chars + message.replace clean(message) + rescue + encoding = detect ? detect[:encoding] : "unknown" + "--broken encoding: #{encoding}" + end + + def encode_utf8(message) + detect = CharlockHolmes::EncodingDetector.detect(message) + if detect && detect[:encoding] + begin + CharlockHolmes::Converter.convert(message, detect[:encoding], 'UTF-8') + rescue ArgumentError => e + Rails.logger.warn("Ignoring error converting #{detect[:encoding]} into UTF8: #{e.message}") + + '' + end + else + clean(message) + end + end + + private + + def clean(message) + message.encode("UTF-16BE", undef: :replace, invalid: :replace, replace: "") + .encode("UTF-8") + .gsub("\0".encode("UTF-8"), "") + end + end +end |