Force attachment filenames to utf-8 before trying to save them

In a database with encoding SQL-ASCII, an invalid utf-8 filename
can be saved but will cause an "invalid byte sequence in UTF-8"
when the filename is prepared for display. In a database with a
UTF-8 encoding, saving the string will cause an error like
"ActiveRecord::StatementInvalid (PG::Error: ERROR: invalid byte
sequence for encoding "UTF8""

2 files changed, 12 insertions, 4 deletions

diff --git a/lib/mail_handler/backends/mail_backend.rb b/lib/mail_handler/backends/mail_backend.rb
index ae3077a72..9b647e2fa 100644
--- a/lib/mail_handler/backends/mail_backend.rb
+++ b/lib/mail_handler/backends/mail_backend.rb
@@ -64,7 +64,12 @@ module MailHandler
             # Return a copy of the file name for the mail part
             def get_part_file_name(part)
                 part_file_name = part.filename
-                part_file_name.nil? ? nil : part_file_name.dup
+                part_file_name = part_file_name.nil? ? nil : part_file_name.dup
+                if part_file_name
+                    part_file_name = CGI.unescape(part_file_name)
+                    part_file_name = convert_string_to_utf8(part_file_name, part.charset)
+                end
+                part_file_name
             end
 
             # Get the body of a mail part
diff --git a/lib/normalize_string.rb b/lib/normalize_string.rb
index de847cd16..1205a1d9c 100644
--- a/lib/normalize_string.rb
+++ b/lib/normalize_string.rb
@@ -76,9 +76,12 @@ def convert_string_to_utf8(s, suggested_character_encoding=nil)
     begin
         result = normalize_string_to_utf8 s, suggested_character_encoding
     rescue EncodingNormalizationError
-        result = s.force_encoding("utf-8").encode("utf-8", :invalid => :replace,
-                                   :undef => :replace,
-                                   :replace => "") if String.method_defined?(:encode)
+        result = s
+        if String.method_defined?(:encode)
+            result = s.force_encoding("utf-8").encode("utf-8", :invalid => :replace,
+                                                               :undef => :replace,
+                                                               :replace => "")
+        end
     end
     result
 end