[h0l0cube]

I have no dog in this fight, but you stated:

> it isn't a good solution for an enormous number of people

.. without providing any insight or justification for that belief. So an interesting and productive tangent might be to elucidate what you believe those flaws are?

Unpacking this question might even lead to some good UX ideas that can be applied to today's review systems?

[fireattack]

I would provide one from someone who is not a dev or SE.

I honestly never fully understand how to read the maillist patch. The plain text format makes it very hard to understand what's going on. I'm sure I will understand it better or even prefer it if I use it long enough, but then again I can instantly understand code reviews on GitHub/GitLab/Gerrit.

[h0l0cube]

I've never had to use a maillist patch myself, but from the ones that I've glanced at, I have this same problem, that formatting, syntax highlighting is absent. It seems like this would be an easy problem to fix by using a better viewer, so that might be enough to make it comprehensible.

[u801e]

> I honestly never fully understand how to read the maillist patch. The plain text format makes it very hard to understand what's going on.

That may be due to the settings in your mail client. If it's displaying plain text in a variable width font and/or not applying syntax highlighting in terms of showing added and removed lines in different colors, that would make the diff more difficult to read.

But some mail clients can do that and it makes reading the diff much easier.

> I'm sure I will understand it better or even prefer it if I use it long enough, but then again I can instantly understand code reviews on GitHub/GitLab/Gerrit.

Essentially, code reviews in a mailing list are much like a discussion thread in Hacker News or Reddit where the thread structure is very similar. The only difference is that most mail clients only allow you to display one message at a time.

In my mail client, Thunderbird, you can see the overall thread structure of a patchset discussion. This is the root message for the thread which serves as the cover letter (which is the equivalent of the PR description) [2]. The first commit in the patch is displayed here [3] (note that I have a plugin that enables diff syntax highlighting). The email subject is the commit message title (with the [PATCH v2 1/3] tag prepended to it). The commit message itself is the beginning of the email, and the diff follows.

Unlike Github (and maybe Gitlab), the commit message and diffstat is treated at the same level as the diff itself. That means you can comment on it just like you would on the diff.

Here, you can see the Junio C Hamano's comments on the second commit in the patch set [4]. He's commenting on the diffstat line which shows 391 lines lines added to the builtin/submodule--helper.c file. Further down in the same message [5], he's commenting on the code inline, much like someone would quote a message here on HN and reply inline to multiple sections of it. It's not really that different compared to comments on a diff in Github or Gitlab other than the fact that it's a reply to an email message rather than a web page.

[1] https://i.imgur.com/QmqUWR8.png

[2] https://i.imgur.com/mILREtf.png

[3] https://i.imgur.com/gdoy5zs.png

[4] https://i.imgur.com/BcTdRRe.png

[5] https://i.imgur.com/cCpqsOL.png

[fireattack]

I will be honest, I don't even use email client :/

[u801e]

True, I suppose most people use Gmail or one of the other major email providers through a webmail interface. I haven't been able to get Gmail or Hotmail to display threaded messages the way they're displayed in Thunderbird and they tend to display messages using a variable width font.

In that context, reviewing code would be difficult, if not impossible, to do via email.

[h0l0cube]

It is one advantage to mailpatch though. A lack of vendor lock-in means you can view the patch using whatever application you want. And there's room for a better mailpatch viewer, if anyone could be bothered to make one.

I'm guessing one disadvantage is the method of diff is hard-coded into the patch. It would be good to switch to word-diff, or ignore whitespace, but I'd imagine these could be applied as transformations on the generic format.

[u801e]

> I'm guessing one disadvantage is the method of diff is hard-coded into the patch. It would be good to switch to word-diff, or ignore whitespace, but I'd imagine these could be applied as transformations on the generic format.

The plugin I use in Thunderbird can switch between unified, context, and side-by-side diff views based on the same email. Adding the transformations you mentioned could be done.

But one limitation that email has over other review tools is the lack of ability to expand the view of the context within the client. The only way I could think of is to have git format-patch generate the diff with the entire context included and then have the client limit the display of that context. But that not have a reasonable fallback for those using clients that aren't capable or configured to do that.

[eru]

That should be an easy problem to fix:

Just send out email in HTML format with the code portions set to fixed width font and syntax highlighting already applied. Should display just fine in GMail.

[u801e]

> Just send out email in HTML format with the code portions set to fixed width font and syntax highlighting already applied

That won't work because people actually download those email messages and apply them to their local repository with the git am command and they also expect to be able to reply to the email inline when commenting on a patch. Also, for mail clients that don't support HTML rendering, it would be much more difficult to read or respond to an HTML email.