Add bin and edit workflow

bin/gems/nokogiri-1.18.3-x86_64-linux-gnu/lib/nokogiri/html4/encoding_reader.rb

@@ -0,0 +1,121 @@
+# frozen_string_literal: true
+
+module Nokogiri
+  module HTML4
+    # Libxml2's parser has poor support for encoding detection.  First, it does not recognize the
+    # HTML5 style meta charset declaration.  Secondly, even if it successfully detects an encoding
+    # hint, it does not re-decode or re-parse the preceding part which may be garbled.
+    #
+    # EncodingReader aims to perform advanced encoding detection beyond what Libxml2 does, and to
+    # emulate rewinding of a stream and make Libxml2 redo parsing from the start when an encoding
+    # hint is found.
+
+    # :nodoc: all
+    class EncodingReader
+      class EncodingFound < StandardError
+        attr_reader :found_encoding
+
+        def initialize(encoding)
+          @found_encoding = encoding
+          super(format("encoding found: %s", encoding))
+        end
+      end
+
+      class SAXHandler < Nokogiri::XML::SAX::Document
+        attr_reader :encoding
+
+        def initialize
+          @encoding = nil
+          super
+        end
+
+        def start_element(name, attrs = [])
+          return unless name == "meta"
+
+          attr = Hash[attrs]
+          (charset = attr["charset"]) &&
+            (@encoding = charset)
+          (http_equiv = attr["http-equiv"]) &&
+            http_equiv.match(/\AContent-Type\z/i) &&
+            (content = attr["content"]) &&
+            (m = content.match(/;\s*charset\s*=\s*([\w-]+)/)) &&
+            (@encoding = m[1])
+        end
+      end
+
+      class JumpSAXHandler < SAXHandler
+        def initialize(jumptag)
+          @jumptag = jumptag
+          super()
+        end
+
+        def start_element(name, attrs = [])
+          super
+          throw(@jumptag, @encoding) if @encoding
+          throw(@jumptag, nil) if /\A(?:div|h1|img|p|br)\z/.match?(name)
+        end
+      end
+
+      def self.detect_encoding(chunk)
+        (m = chunk.match(/\A(<\?xml[ \t\r\n][^>]*>)/)) &&
+          (return Nokogiri.XML(m[1]).encoding)
+
+        if Nokogiri.jruby?
+          (m = chunk.match(/(<meta\s)(.*)(charset\s*=\s*([\w-]+))(.*)/i)) &&
+            (return m[4])
+          catch(:encoding_found) do
+            Nokogiri::HTML4::SAX::Parser.new(JumpSAXHandler.new(:encoding_found)).parse(chunk)
+            nil
+          end
+        else
+          handler = SAXHandler.new
+          parser = Nokogiri::HTML4::SAX::PushParser.new(handler)
+          begin
+            parser << chunk
+          rescue
+            Nokogiri::SyntaxError
+          end
+          handler.encoding
+        end
+      end
+
+      def initialize(io)
+        @io = io
+        @firstchunk = nil
+        @encoding_found = nil
+      end
+
+      # This method is used by the C extension so that
+      # Nokogiri::HTML4::Document#read_io() does not leak memory when
+      # EncodingFound is raised.
+      attr_reader :encoding_found
+
+      def read(len)
+        # no support for a call without len
+
+        unless @firstchunk
+          (@firstchunk = @io.read(len)) || return
+
+          # This implementation expects that the first call from
+          # htmlReadIO() is made with a length long enough (~1KB) to
+          # achieve advanced encoding detection.
+          if (encoding = EncodingReader.detect_encoding(@firstchunk))
+            # The first chunk is stored for the next read in retry.
+            raise @encoding_found = EncodingFound.new(encoding)
+          end
+        end
+        @encoding_found = nil
+
+        ret = @firstchunk.slice!(0, len)
+        if (len -= ret.length) > 0
+          (rest = @io.read(len)) && ret << (rest)
+        end
+        if ret.empty?
+          nil
+        else
+          ret
+        end
+      end
+    end
+  end
+end