Issues with handling quotation marks in attachment names

[jamo]

I came across to this issue in Ruby On Rails (rails/rails#14158), and have traced it, and it seems that it might be actually a bug in mail-gem.

I have tried to fix it, but my dirty fix makes one other test to fail:

 1) Mail::UnstructuredField displaying encoded field and decoded value should encode additional special characters inside encoded-word-encoded strings
     Failure/Error: @field.encoded.should eq result

       expected: "Subject: =?UTF-8?Q?Her_er_=C3=A6=28=29<>@,;:\\=22/[]=3F.=3D?=\r\n"
            got: "Subject: =?UTF-8?Q?Her_er_=C3=A6=28=29<>@,;:=22/[]=3F.=3D?=\r\n"

       (compared using ==)

       Diff:
       @@ -1,2 +1,2 @@
       -Subject: =?UTF-8?Q?Her_er_=C3=A6=28=29<>@,;:\=22/[]=3F.=3D?=
       +Subject: =?UTF-8?Q?Her_er_=C3=A6=28=29<>@,;:=22/[]=3F.=3D?=

My "fix": https://github.com/jamox/mail/blob/fixing_fail_when_name_has_quotes/lib/mail/encodings.rb#L98-L110

---

Error occurs when in: https://github.com/mikel/mail/blob/master/lib/mail/attachments_list.rb#L40

    def []=(name, value)
      encoded_name = Mail::Encodings.decode_encode name, :encode
      default_values = { :content_type => "#{set_mime_type(name)}; filename=\"#{encoded_name}\"",
                         :content_transfer_encoding => "#{guess_encoding}",
                         :content_disposition => "#{@content_disposition_type}; filename=\"#{encoded_name}\"" }

we have name = 'invoice "for you".pdf' and then we insert it into

 default_values = { :content_type => "#{set_mime_type(name)}; filename=\"#{encoded_name}\"",

Thus getting

 default_values = { :content_type => "#{set_mime_type(name)}; filename=\"invoice \"for you\".pdf\"",

And later we get the filename \"invoice \"for you\".pdf\" => "invoice "for you".pdf"...

Id be happy to fix this (in case this ain't due to misuse of this library) :)

[joeyAghion]

I ran into this recently. The cleanest thing appeared to be manually removing/replacing quotation marks in the names before attaching files, but it would be nice to have a proper fix. I'm happy to PR if someone can provide guidance about the correct encoding.

[j15e]

I got into this issue too. It would be nice to raise if the quotes isn't supported in attachment filename rather than silently creating an invalid email.