Bug 207981 – input type='number' with maxlength attribute is ignored

• Component: Forms
• Status: RESOLVED INVALID

[karl]

Created attachment 391234 [details]
test case for input/number and maxlength

Steps to reproduce the problem:
1. Open the test case
2. Type 123 in the input form

What is the expected behavior?
12 is displayed

What went wrong?
123 is displayed

Did this work before? N/A 

Does this work in other browsers? N/A

Safari version: Release 100 (Safari 13.2, WebKit 15610.1.2.1))  Channel: Tech Preview
OS Version: OS X 10.15
Flash Version: 

What is the spec saying https://html.spec.whatwg.org/multipage/input.html#attr-input-maxlength

> The maxlength attribute, when it applies, is a form control maxlength attribute.

Following https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#attr-fe-maxlength

> Constraint validation: If an element has a maximum allowed value length, its dirty value flag is true, its value was last changed by a user edit (as opposed to a change made by a script), and the JavaScript string length of the element's API value is greater than the element's maximum allowed value length, then the element is suffering from being too long.
> 
> User agents may prevent the user from causing the element's API value to be set to a value whose JavaScript string length is greater than the element's maximum allowed value length.

It doesn't seem a hard constraint, but

## results for type='number'

1. enter into the url bar
```
data:text/html,<input type='number' maxlength='2'/>
```
2. type 123

Results in different browsers
* firefox: 12  (75.0a1 (2020-02-18) (64-bit))
* chrome: 123 (Version 82.0.4062.4 (Build officiel) canary (64 bits))
* safari: 123 (Release 100 (Safari 13.2, WebKit 15610.1.2.1))

## results for type='text'

```
data:text/html,<input type='text' maxlength='2'/>
```
Results in different browsers
* firefox: 12  (75.0a1 (2020-02-18) (64-bit))
* chrome: 12 (Version 82.0.4062.4 (Build officiel) canary (64 bits))
* safari: 12 (Release 100 (Safari 13.2, WebKit 15610.1.2.1))

This was originally filed as a bug on mozilla bugzilla
https://bugzilla.mozilla.org/show_bug.cgi?id=1616620

[karl]

tkent commented on the chromium issue.
https://bugs.chromium.org/p/chromium/issues/detail?id=1054251#c2

https://html.spec.whatwg.org/multipage/input.html#number-state-(type=number)

> The following content attributes must not be specified and do not apply to the element: accept, alt, checked, dirname, formaction, formenctype, formmethod, formnovalidate, formtarget, height, maxlength, minlength, multiple, pattern, size, src, and width.

So probably webkit is fine. and firefox needs to fix it.