Fixing parens manually triggers malformed MathJSON

[sritchie]

Description

(@jefffriesen found this while playing with mentat-collective/MathLive.cljs#11.)

to repro:

• type an expression like 1+cos()y
• decide you want to pull y into the parens
• delete the right paren and retype it to the right of y

The Mathfield eagerly inserts a multiplication dot and parses the input as

Full interaction:

MathJSON:

[
  "Sequence",
  [
    "Add",
    1,
    [
      "Sequence",
      [
        "Cos",
        [
          "Error",
          [
            "ErrorCode",
            "'expected-close-delimiter'",
            "\\right)"
          ],
          ["Latex", "'('"]
        ]
      ],
      [
        "Error",
        ["ErrorCode", "'expected-open-delimiter'", "\\left"],
        ["Latex", "'\\right.'"]
      ],
      "y"
    ]
  ],
  [
    "Error",
    ["ErrorCode", "'expected-open-delimiter'", "("],
    ["Latex", "')'"]
  ]
]

[arnog]

I think that's a duplicate of #1656

[gerryfletch]

I'm noticing this quite frequently with parens, especially because if I type ( it'll create the corresponding ) for me, but pressing backspace to write into it creates the .

[arnog]

Fixed now.