"Remove space between attributes when after a quoted value" results in invalid HTML

[ghost]

After updating from 2.9.4 to a newer version, we observed that we get invalid HTML. This is likely related to the change "HTML: remove space between attributes when after a quoted value" in 2.9.5.

Raw HTML

    <meta property="og:locale" content="en_US" />
    <meta property="og:site_name" content="InfoSec Handbook – information security blog" />
    <meta property="og:type" content="website" />
    <meta property="og:title" content="InfoSec Handbook – information security blog" />
    <meta property="og:description" content="A non-profit information security blog, operated by a community of InfoSec professionals – no ads, no tracking, free and secure." />
    <meta property="og:url" content="https://infosec-handbook.eu/" />
    <meta property="og:image" content="https://infosec-handbook.eu/img/l128.pn" />

Expected result (prior to 2.9.5)

<meta property="og:locale" content="en_US"><meta property="og:site_name" content="InfoSec Handbook – information security blog"><meta property="og:type" content="website"><meta property="og:title" content="InfoSec Handbook – information security blog"><meta property="og:description" content="A non-profit information security blog, operated by a community of InfoSec professionals – no ads, no tracking, free and secure."><meta property="og:url" content="https://infosec-handbook.eu/"><meta property="og:image" content="https://infosec-handbook.eu/img/l128.png">

Actual result (2.9.5 and newer)

<meta property="og:locale"content="en_US"><meta property="og:site_name"content="InfoSec Handbook – information security blog"><meta property="og:type"content="website"><meta property="og:title"content="InfoSec Handbook – information security blog"><meta property="og:description"content="A non-profit information security blog, operated by a community of InfoSec professionals – no ads, no tracking, free and secure."><meta property="og:url"content="https://infosec-handbook.eu/"><meta property="og:image"content="https://infosec-handbook.eu/img/l128.png">

In this example, minify removes whitespaces between …" content…, resulting in …"content….

Problem

The nu HTML checker and the developer mode of web browsers (e.g., Firefox) detect this as invalid HTML:

Error: No space between attributes.
At line 1, column 846
rty="og:locale"content="en_US"

There is no minify option to disable this new behavior, introduced in 2.9.5. --html-keep-whitespace doesn't disable the behavior.

Workaround

Downgrade to minify 2.9.4.

[tdewolff]

Thank you for the notice! This was an optimization taken from another minifier, and I was sure the spec allowed this. However, upon second inspection of the HTML spec at https://html.spec.whatwg.org/multipage/syntax.html#start-tags it becomes clear that "Attributes must be separated from each other by one or more ASCII whitespace".

[ghost]

c2f5ff6 fixed the problem. We just rechecked on Arch Linux with 2.9.9.