<input> with no specified value or size has incorrect width

[frewsxcv]

$ cat /tmp/hi.html
<input>

Chrome (and Firefox):

Servo:

Relevant section of spec

[frewsxcv]

On a similar note:

$ cat /tmp/hi.html
<input size=50>

Chrome (and Firefox):

Servo:

[frewsxcv]

Possibly related to #4378

[SimonSapin]

The size attribute does have an effect in:

<input type=text size=50>

So I’m guessing that where we’re implementing this (emphasis added):

https://html.spec.whatwg.org/multipage/rendering.html#the-input-element-as-a-text-entry-widget:the-input-element

If an input element whose type attribute is in one of the above states has a size attribute, and parsing that attribute's value using the rules for parsing non-negative integers doesn't generate an error, then the user agent is expected to use the attribute as a presentational hint for the 'width' property on the element, with the value obtained from applying the converting a character width to pixels algorithm to the value of the attribute.

… we’re not accounting for the default state of the type attribute:

https://html.spec.whatwg.org/multipage/forms.html#attr-input-type

The missing value default is the Text state.

[SimonSapin]

Relevant code is synthesize_presentational_hints_for_legacy_attributes in components/script/dom/element.rs

[TheKK]

Hi!
This issue looks like a nice place for me to start, can I take this one?

[Ms2ger]

It's yours! Look for "nonsense" in components/script/dom/element.rs.

[TheKK]

Hi, here my modification. I compare the rendering result with Firefox and has no difference. Could you help me checking the commit, thanks.

[SimonSapin]

Hi @TheKK. Thanks for your contribution! Please open a pull request so that we can use the usual tooling for code review.