Help with unsupported charsets

[deepakprabhakara]

I have collected a small list of logs for unsupported charsets. Here's the list:-

• ISO646-US
• ISO: Western
• cp936
• cp-850
• 136
• utf-7
• ibm850

As far as I understand ISO646-US is "us-ascii", ISO: Western is "iso8859" and cp936 is "gb2312". Is this correct?

I have been unable to figure out the rest of the encodings although cp-850 and ibm850 seem to be the same.

Does anyone have an idea about these charsets and if they can be supported in this library easily?

[deepakprabhakara]

Looks like cp-850 and ibm850 is charmap.CodePage850

[jhillyerd]

Looks like you took care of most of these. Seems like Go does not support UTF-7 out of the box, not sure if that's because Rob Pike invented UTF-8 and doesn't want it. We could leverage:

https://github.com/cention-sany/utf7

@cention-sany appears to make use of a heavily modified version of the older go.enmime

I'd like to avoid adding a bunch of dependencies if possible, but I'd rather one import than bring in iconv, since it wraps a C library; complicating the build.

[deepakprabhakara]

Sounds good to me, I'd avoid iconv as well.

[jhillyerd]

Looks like https://github.com/emersion/go-imap/tree/v1/utf7 may be a more idiomatic implementation. Turns out that UTF-7 was actually defined in the IMAP RFC.

[cention-sany]

Just wanna comment that package https://github.com/cention-sany/utf7 is https://tools.ietf.org/html/rfc2152 compliance meanwhile https://github.com/emersion/go-imap/tree/v1/utf7 seem to be https://tools.ietf.org/html/rfc3501#section-5.1.3 which actually two slightly different UTF-7.

[jhillyerd]

Good to know, skimming rfc2152, it was specifically designed for internet mail content, so your implementation would be the better choice for enmime.

[deepakprabhakara]

@jhillyerd Nice one

[jhillyerd]

If I had known it was only going to take 3 lines of code to implement, I might not have waited two years to fix this. 🙄