Backport Mail's encoding code from 2.5 for Ruby 1.9

Decoding messages in Ruby 1.9 was screwing up but not dying like 1.8. Backporting this fixes the problem.

1 files changed, 45 insertions, 0 deletions

diff --git a/lib/mail_handler/backends/mail_extensions.rb b/lib/mail_handler/backends/mail_extensions.rb
index 34ced7319..611b44c4c 100644
--- a/lib/mail_handler/backends/mail_extensions.rb
+++ b/lib/mail_handler/backends/mail_extensions.rb
@@ -124,4 +124,49 @@ module Mail
             end
         end
     end
+
+    # HACK: Backport encoding fixes for Ruby 1.9 from Mail 2.5
+    # Can be removed when Rails relies on Mail > 2.5
+    class Ruby19
+        def Ruby19.b_value_decode(str)
+            match = str.match(/\=\?(.+)?\?[Bb]\?(.+)?\?\=/m)
+            if match
+                encoding = match[1]
+                str = Ruby19.decode_base64(match[2])
+                str.force_encoding(fix_encoding(encoding))
+            end
+            decoded = str.encode("utf-8", :invalid => :replace, :replace => "")
+            decoded.valid_encoding? ? decoded : decoded.encode("utf-16le", :invalid => :replace, :replace => "").encode("utf-8")
+        end
+
+        def Ruby19.q_value_decode(str)
+            match = str.match(/\=\?(.+)?\?[Qq]\?(.+)?\?\=/m)
+            if match
+                encoding = match[1]
+                str = Encodings::QuotedPrintable.decode(match[2])
+                str.force_encoding(fix_encoding(encoding))
+            end
+            decoded = str.encode("utf-8", :invalid => :replace, :replace => "")
+            decoded.valid_encoding? ? decoded : decoded.encode("utf-16le", :invalid => :replace, :replace => "").encode("utf-8")
+        end
+
+        # mails somtimes includes invalid encodings like iso885915 or utf8 so we transform them to iso885915 or utf8
+        # TODO: add this as a test somewhere
+        # Encoding.list.map{|e| [e.to_s.upcase==fix_encoding(e.to_s.downcase.gsub("-", "")), e.to_s] }.select {|a,b| !b}
+        #  Encoding.list.map{|e| [e.to_s==fix_encoding(e.to_s), e.to_s] }.select {|a,b| !b}
+        def Ruby19.fix_encoding(encoding)
+            case encoding
+                # ISO-8859-15, ISO-2022-JP and alike
+                when /iso-?(\d{4})-?(\w{1,2})/i then return "ISO-#{$1}-#{$2}"
+                # "ISO-2022-JP-KDDI"  and alike
+                when /iso-?(\d{4})-?(\w{1,2})-?(\w*)/i then return "ISO-#{$1}-#{$2}-#{$3}"
+                # UTF-8, UTF-32BE and alike
+                when /utf-?(\d{1,2})?(\w{1,2})/i then return "UTF-#{$1}#{$2}"
+                # Windows-1252 and alike
+                when /Windows-?(.*)/i then return "Windows-#{$1}"
+                #more aliases to be added if needed
+                else return encoding
+            end
+        end
+    end
 end