## List of `contenteditable` Browser Inconsistencies
Playground: http://jsbin.com/iwEWUXo/2/edit?js,console,output

### `document.execCommand` commands
* Firefox: When the `contenteditable` element is a custom element, an error is
  thrown when trying to apply one of the following commands. As per:
  http://jsbin.com/etepiPOn/1/edit?html,css,js,console,output
* Chrome has some magic to re-focus the `contenteditable` when a command is
  executed and the selection is not collapsed:
  http://jsbin.com/papi/1/edit?html,js,output
* "`insertBrOnReturn`": http://jsbin.com/IQUraXA/1/edit?html,js,output
* "`insertHTML`":
  - http://jsbin.com/elicInov/2/edit?html,js,output
  - Chrome tries to be clever by applying inline styles/SPANs with `line-
    height`: http://jsbin.com/ilEmudi/4/edit?css,js,output
  - Chrome applies styling to invalid markup, Firefox allows invalid markup:
    http://jsbin.com/ObiBoweG/1/edit?js,console,output
  - Given an empty P element, Chrome will wrap inserted text nodes not in a P,
    whereas Firefox will not: http://jsbin.com/olEbecEM/1/edit?js,output
  - Given content of `<p>1|</p>`, when inserting HTML of `<p>2</p>`, Chrome will
    merge the inserted P element into the existing P element, whereas Firefox
    will not: http://jsbin.com/uvEdacoz/6/edit?js,output
  - Given content of `<p>1|</p>`, when inserting HTML of `<p>2<o></o></p>`,
    Chrome will merge the inserted P element into the existing P element
    *excluding any custom elements*, whereas Firefox will not:
    http://jsbin.com/tuleq/3/edit?js,output
  - Given content of `<p>1<br>|</p>`, when inserting HTML of `2<p>3</p>`, Chrome
    will append the inserted unwrapped text node immediately into the existing
    paragraph, whereas Firefox will append a BR element followed by the text
    node: http://jsbin.com/uvEdacoz/7/edit?js,output
  - Given a selection across multiple P elements, Firefox will insert the
    content outside of any P element: http://jsbin.com/jiviniti/4/edit?js,output
* "`formatBlock`": http://jsbin.com/UTUDaPoC/1/edit?html,js,output
* "`bold`": http://jsbin.com/IxiSeYO/4/edit?html,js,output
* "`outdent`":
  - Chrome removes BLOCKQUOTE content formatting:
    http://jsbin.com/okAYaHa/1/edit?html,js,output
  - Chrome removes collapsed selection formatting:
    http://jsbin.com/IfaRaFO/1/edit?html,js,output
* "`insertOrderedList`"/"`insertOrderedList`":
  - Chrome nests list inside of block elements:
    http://jsbin.com/eFiRedUc/1/edit?html,js,output
  - Chrome removes SPAN: http://jsbin.com/abOLUNU/1/edit?html,js,output
  - Chrome tries to be clever by applying inline styles/SPANs with `line-
    height`: http://jsbin.com/OtemujAY/10/edit?html,css,js,output
  - Chrome does not add a BR element when there is no `DOCTYPE`:
    http://jsbin.com/sasec/1/edit?js,console,output
    https://code.google.com/p/chromium/issues/detail?id=396654&thanks=396654&ts=1406132418
* "`indent`":
  - Chrome nests BLOCKQUOTE inside of P:
    http://jsbin.com/oDOriyU/3/edit?html,js,output
  - Chrome nests ULs inside of ULs:
    - http://jsbin.com/ORikUPa/3/edit?html,js,output
    - http://jsbin.com/kuvi/1/edit?js,output
  - Chrome adds redundant `style` attribute:
    http://jsbin.com/AkasOzu/1/edit?html,js,output
  - Chrome converts BRs to Ps: http://jsbin.com/zeti/2/edit?js,output
  - Firefox does not perform transformation upon Ps containing BRs:
    http://jsbin.com/yiyaq/1/edit?js,output
* "`createLink`"
  - Firefox does not create A if selection is empty:
    http://jsbin.com/tutufi/2/edit?js,output
* "`delete`":
  - Given a selection across multiple P elements, Firefox will place the caret
    outside of any P element: http://jsbin.com/xopivama/3/edit?js,output

### `Document.queryCommandState`
* Browser magic: Chrome and Firefox report command state to be true after
  applying a command to a collapsed selection, but why?:
  http://jsbin.com/eDOxacI/1/edit?js,console,output
* `superscript`: Firefox: Returns false when a whole `SUP` is selected:
  http://jsbin.com/marox/1/edit?js,console,output
* `subscript`: Firefox: Returns false when a whole `SUB` is selected:
  http://jsbin.com/marox/1/edit?js,console,output
  - True for all inline elements?
* Firefox throws `NS_ERROR_UNEXPECTED` error for `insertUnorderedList` and
  `insertOrderedList` when a contenteditable is not focussed, see:
  https://github.com/guardian/scribe/issues/208

### `Element.focus`
* Firefox: Giving focus to a `contenteditable` will place the caret outside of
  any block elements. Chrome behaves correctly by placing the caret at the
  earliest point possible inside the first block element:
  http://jsbin.com/eLoFOku/1/edit?js,console,output

### Events
* Chrome tries to be clever by applying inline styles/SPANs with `line-height`
  on \<backspace> or \<delete> keyboard events:
  http://jsbin.com/isIdoKA/3/edit?html,css,js,output
* Firefox breaks out of P mode on \<backspace> or \<delete> keyboard events when
  HTML has indentation between block elements:
  http://jsbin.com/EyuKase/1/edit?js,output

## Other
* Chrome (<= 28(?)): `TreeWalker` does not work properly with
  `DocumentFragment`s: http://stackoverflow.com/questions/21803827/chrome-28
  -treewalker-not-working-with-documentfragments
* Firefox: Selection object never gets access to text nodes, only parent
  elements: http://jsbin.com/rotus/2/edit?js,output,console

### `Range.commonAncestorContainer`
* Firefox: Returns `P` when a whole `SUP` is selected:
  http://jsbin.com/xoqul/1/edit?js,console,output

### `Selection.getRangeAt`
* Chrome (< 42): Selection.getRangeAt() returns an incorrect range when in shadow DOM
  https://code.google.com/p/chromium/issues/detail?id=380690

### `Selection.isCollapsed`
* Chrome: Selection.isCollapsed is incorrect when in shadow DOM
  https://code.google.com/p/chromium/issues/detail?id=447523
  http://jsfiddle.net/7zgegoda/2/