Support <details> without <summary>

[the-blank-x]

URL

The bottom of the comment in https://tildes.net/~games/160b/any_android_games_that_are_worth_playing_these_days#comment-85o1
https://tildes.net/~talk/145a/unpopular_opinion_wikipedias_old_look_was_much_better_than_the_new_one#comment-7ovd

Screenshot

Description

Whenever a <details> element with no <summary> is encountered, Link Hints does not add a hint to the default "Details" text of the element. I can also reproduce it here: t.html.gz

Debug info

Debug info

{
  "version": "1.3.1",
  "browser": "firefox",
  "userAgent": "Mozilla/5.0 (X11; Linux x86_64; rv:113.0) Gecko/20100101 Firefox/113.0",
  "browserInfo": {
    "name": "Firefox",
    "vendor": "LibreWolf",
    "version": "113.0.2-1",
    "buildID": "20230531125735"
  },
  "platformInfo": {
    "os": "linux",
    "arch": "x86-64"
  },
  "storage.sync": {
    "normal.ctrl-j": "EnterHintsMode_Click",
    "normal.ctrl-k": "EnterHintsMode_BackgroundTab",
    "normal.ctrl-J": "EnterHintsMode_ManyClick",
    "normal.ctrl-K": "EnterHintsMode_ManyTab",
    "normal.ctrl-L": "EnterHintsMode_Select",
    "normal.ctrl-:": "EnterHintsMode_ForegroundTab",
    "debug.Background.PREFER_WINDOWS": false,
    "debug.ElementManager.ROLES_CLICKABLE": [
      "button",
      "checkbox",
      "link",
      "menuitem",
      "menuitemcheckbox",
      "menuitemradio",
      "option",
      "radio",
      "searchbox",
      "spinbutton",
      "switch",
      "tab",
      "textbox"
    ],
    "hints.ctrl-Enter": "ActivateHintAlt",
    "debug.ElementManager.ATTRIBUTES_CLICKABLE": [
      "aria-checked",
      "aria-selected",
      "data-dismiss",
      "data-ember-action",
      "data-image-url",
      "data-line-number",
      "data-permalink-path"
    ],
    "debug.ElementManager.REGEX_CLICKABLE_CLASS": "\\bcm-|ͼ|\\bmtk|sparkline-year-label|js-wiki-toggle-collapse"
  },
  "storage.local": {
    "tutorialShown": true
  },
  "language": "en-US"
}

[lydell]

TIL:

• The HTML specification for <details> requires the <summary> element to be present, but still defines how user agents should deal with a missing summary:

  The first summary element child of the element, if any, represents the summary or legend of the details. If there is no child summary element, the user agent should provide its own legend (e.g. "Details").

• That sites actually rely on this.

Test case:

stuff