Facet colouring not matching text correctly under some circumstances

[orual]

See below. Assuming the utf8 code point to glyph calculation is a bit off, since Skyfeed renders it correctly.

JSON for problematic posts:

{
  "$type": "app.bsky.feed.defs#postView",
  "record": {
    "$type": "app.bsky.feed.post",
    "text": "já dá, o padrão é 2 mas se quiser mais tem que ser assinante no patreon.com/deckblue",
    "reply": {
      "root": {
        "$type": "com.atproto.repo.strongRef",
        "cid": "bafyreianr5xb5zad2mw2wmjstfontvnpuas2cpficadcbg4n3rfjaqpzbq",
        "uri": "at://did:plc:y6xed5noeivqfdtar4yetvz4/app.bsky.feed.post/3l2xliv7tym2r"
      },
      "parent": {
        "$type": "com.atproto.repo.strongRef",
        "cid": "bafyreianr5xb5zad2mw2wmjstfontvnpuas2cpficadcbg4n3rfjaqpzbq",
        "uri": "at://did:plc:y6xed5noeivqfdtar4yetvz4/app.bsky.feed.post/3l2xliv7tym2r"
      }
    },
    "embed": {
      "$type": "app.bsky.embed.external",
      "external": {
        "uri": "https://patreon.com/deckblue",
        "title": "Get more from deck.blue on Patreon",
        "description": "Get the most out of Bluesky.",
        "thumb": {
          "$type": "blob",
          "mimeType": "image/png",
          "size": 243267,
          "ref": {
            "$link": "bafkreihzylmuca64wg7kh5eg25h6uekgtwr2h2osmbitiu7keyhcaqdj5y"
          }
        }
      }
    },
    "langs": ["en", "pt"],
    "facets": [
      {
        "$type": "app.bsky.richtext.facet",
        "index": { "byteStart": 68, "byteEnd": 88 },
        "features": [
          {
            "$type": "app.bsky.richtext.facet#link",
            "uri": "https://patreon.com/deckblue"
          }
        ]
      }
    ],
    "tags": [],
    "createdAt": "2024-08-30T20:34:04.326Z"
  },
  "author": {
    "did": "did:plc:w342borqxtyo2pul67ec2pwt",
    "handle": "deck.blue",
    "displayName": "deck.blue",
    "avatar": "https://cdn.bsky.app/img/avatar/plain/did:plc:w342borqxtyo2pul67ec2pwt/bafkreiec6yihxyfgua7myrxcfx75opofiu6l5wm4jzjrn3irlklynmagmy@jpeg",
    "viewer": {
      "muted": false,
      "blockedBy": false,
      "following": "at://did:plc:bsnnxdb2se2cdwsbav3ffhe5/app.bsky.graph.follow/3kcgfkk6gci2w"
    },
    "labels": []
  },
  "uri": "at://did:plc:w342borqxtyo2pul67ec2pwt/app.bsky.feed.post/3l2xm3m2lvm2f",
  "cid": "bafyreicnhzkvrhzepcn7nmahul3aq6fs2wdmal3mskftlcyz7oagci6sqe",
  "embed": {
    "$type": "app.bsky.embed.external#view",
    "external": {
      "$type": "app.bsky.embed.external#viewExternal",
      "uri": "https://patreon.com/deckblue",
      "title": "Get more from deck.blue on Patreon",
      "description": "Get the most out of Bluesky.",
      "thumb": "https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:w342borqxtyo2pul67ec2pwt/bafkreihzylmuca64wg7kh5eg25h6uekgtwr2h2osmbitiu7keyhcaqdj5y@jpeg"
    }
  },
  "replyCount": 1,
  "repostCount": 2,
  "likeCount": 1,
  "viewer": { "replyDisabled": false },
  "labels": [],
  "indexedAt": "2024-08-30T20:34:04.326Z"
}

{
  "$type": "app.bsky.feed.defs#postView",
  "record": {
    "$type": "app.bsky.feed.post",
    "text": "isso é com o @bsky.app! o deck.blue não é oficial",
    "reply": {
      "root": {
        "$type": "com.atproto.repo.strongRef",
        "cid": "bafyreie5rdgtef6giqu2dnxlacyb7ste5rp6p65pokxeriejq726gylkaa",
        "uri": "at://did:plc:sn7b23h46p4l3hkhm6mwpwzm/app.bsky.feed.post/3l2xpfyk3f72v"
      },
      "parent": {
        "$type": "com.atproto.repo.strongRef",
        "cid": "bafyreie5rdgtef6giqu2dnxlacyb7ste5rp6p65pokxeriejq726gylkaa",
        "uri": "at://did:plc:sn7b23h46p4l3hkhm6mwpwzm/app.bsky.feed.post/3l2xpfyk3f72v"
      }
    },
    "langs": ["en", "pt"],
    "facets": [
      {
        "$type": "app.bsky.richtext.facet",
        "index": { "byteStart": 14, "byteEnd": 23 },
        "features": [
          {
            "$type": "app.bsky.richtext.facet#mention",
            "did": "did:plc:z72i7hdynmk6r22z27h6tvur"
          }
        ]
      },
      {
        "$type": "app.bsky.richtext.facet",
        "index": { "byteStart": 27, "byteEnd": 36 },
        "features": [
          {
            "$type": "app.bsky.richtext.facet#link",
            "uri": "https://deck.blue"
          }
        ]
      }
    ],
    "tags": [],
    "createdAt": "2024-08-30T22:39:19.254Z"
  },
  "author": {
    "did": "did:plc:w342borqxtyo2pul67ec2pwt",
    "handle": "deck.blue",
    "displayName": "deck.blue",
    "avatar": "https://cdn.bsky.app/img/avatar/plain/did:plc:w342borqxtyo2pul67ec2pwt/bafkreiec6yihxyfgua7myrxcfx75opofiu6l5wm4jzjrn3irlklynmagmy@jpeg",
    "viewer": {
      "muted": false,
      "blockedBy": false,
      "following": "at://did:plc:bsnnxdb2se2cdwsbav3ffhe5/app.bsky.graph.follow/3kcgfkk6gci2w"
    },
    "labels": []
  },
  "uri": "at://did:plc:w342borqxtyo2pul67ec2pwt/app.bsky.feed.post/3l2xt3kpefu2l",
  "cid": "bafyreibd7mdultuln3rqvj4lnhxvyvb5yiufczx7vk2lvdzx62trauomjy",
  "replyCount": 0,
  "repostCount": 0,
  "likeCount": 0,
  "viewer": { "replyDisabled": false },
  "labels": [],
  "indexedAt": "2024-08-30T22:39:19.254Z"
}

[orual]

Added the Skyfeed feature to copy out JSON of posts to Morpho to help debug this and other things more easily. Copies out the Morpho-specific version rather than AT Protocol lexicon-compatible, but that's more useful for debug anyway.

[orual]

I hate utf16 encoding.