Quotation depth is too much in bridged threaded messages

[MurzNN]

At now bridge seems includes as quotation text from all previous replies to message text in thread, as result those messages look ugly on Element-Android, here is issue about this: element-hq/element-android#3460

But the source of this problem is too much quotation of mx-puppet-slack.

Here is exact example of message, here is the source:

{
  "type": "m.room.message",
  "sender": "@_slackpuppet___t02_f_l_v1_h_n=2d_u01_r_x635_e2_j:ru-matrix.org",
  "content": {
    "msgtype": "m.text",
    "body": "> <@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u0220_r5_p16_z:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u0220_r5_p16_z:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u0220_r5_p16_z:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org> > <@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org> <https://github.com/vercel/nextjs-subscription-payments>\n> > > > > > > \n> > > > > > > I rewrote the code using Prisma and now rewriting it using Keystone\n> > > > > > \n> > > > > > Ah that's really helpful, thank you both! I think it's more to do with mounting a custom endpoint on the Keystone server that I haven't been able to get around; I did a similar think with `app.use('/webhook/stripe')`  on a custom server in a K5 project but haven't got that working in Next yet. If I manage to do it, I'll throw together an example repo with a generic webhook example\n> > > > > \n> > > > > You could use the next-lite example\n> > > > \n> > > > And in your pages folder, add api/webhooks\n> > > \n> > > Thinking that as a stop-gap I could use Next API routes to take untyped JSON from a webhook and transform that into a GraphQL query to communicate with Keystone to avoid a custom server if that's not possible in K6\n> > \n> > That's super useful, thank you!\n> \n> No problem! Let me know if you have anymore questions\n\njunaidkabani3 thanks so much for sharing what you've learned! 🙇‍♂️ 💙\n\nHope next steps are productive dan.w 🍀 🤞",
    "format": "org.matrix.custom.html",
    "formatted_body": "<mx-reply><blockquote>\n\t<a href=\"https://matrix.to/#/!AkMxTNaaaxjawWEjiO:ru-matrix.org/$XnJFHuBAWpFAOn8SH3nNK0Xll3XC9eqxSWhOJsLYvtA\">In reply to</a>\n\t<a href=\"https://matrix.to/#/@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org\">@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org</a>\n\t<br><p>No problem! Let me know if you have anymore questions</p>\n</blockquote></mx-reply><p><a href=\"https://matrix.to/#/@_slackpuppet___t02_f_l_v1_h_n=2d_u015_d_s_p30_n_l:ru-matrix.org\">junaidkabani3</a> thanks so much for sharing what you&#39;ve learned! 🙇‍♂️ 💙<br><br>Hope next steps are productive <a href=\"https://matrix.to/#/@_slackpuppet___t02_f_l_v1_h_n=2d_u0220_r5_p16_z:ru-matrix.org\">dan.w</a> 🍀 🤞</p>",
    "source": "slack",
    "m.relates_to": {
      "m.in_reply_to": {
        "event_id": "$XnJFHuBAWpFAOn8SH3nNK0Xll3XC9eqxSWhOJsLYvtA"
      }
    },
    "external_url": "https://keystonejs.slack.com/archives/C01STDMEW3S/p1622707081.340700"
  },
  "origin_server_ts": 1622707081145,
  "unsigned": {
    "age": 69181602
  },
  "event_id": "$R6jn3jF72Ui86X1awuI2F5ahgINzvYVCa-mEsRQcHMQ",
  "room_id": "!AkMxTNaaaxjawWEjiO:ru-matrix.org"
}

And screenshot from Element-Web:

And from Android:

I think that quotation depth of one previous message will be enough.

But let make this depth configurable?

[auscompgeek]

The bug here is that the body reply fallback is invalid per the spec. Looks like the formatted_body reply fallback is fine, oddly enough.