Bundled themes should pass version to wp_enqueue_style() to ensure proper cache busting

[dswebsme]

Bundled themes should pass the current theme version ($ver parameter) to wp_enqueue_style() to ensure theme stylesheets properly bypass cache after being updated.

Dev discussion on the subject took place here: #39997

This affects themes twentyten - twentyseventeen. Bundled theme twentynineteen already passes a dynamic $ver parameter.

Key details provided by @desrosj

I audited the stylesheet last edit dates and the version specified in the wp_enqueue_style() call. Let's leave Twenty Nineteen alone (that was already calling wp_get_theme()->get( 'Version' ), and make sure the dates are correct (and actually present) for each stylesheet. Results (dates in YYYY-MM-DD):

	Last Modified	Current Specified Version
Twenty Ten
blocks.css	2018-12-18	20181018*
editor-blocks.css	2018-12-18	none
style.css	2019-02-07	none
Twenty Eleven
blocks.css	2019-01-02	20181230*
editor-blocks.css	2019-01-02	20181230*
style.css	2019-04-04	none
/inc/theme-options.css	2011-06-02	2011-04-28*
/colors/dark.css	2019-04-04	null
Twenty Twelve
style.css	2019-04-06	none
/css/blocks.css	2019-04-06	20181230*
/css/ie.css	2015-02-14	20121010*
/css/editor-blocks.css	2019-04-06	20181230*
Twenty Thirteen
style.css	2019-02-07	2013-07-18*
/css/blocks.css	2019-01-02	2018-12-30*
/css/ie.css	2015-02-14	2013-07-18*
/css/editor-blocks.css	2019-01-02	2018-12-30*
Twenty Fourteen
style.css	2019-02-07	none
/css/blocks.css	2019-01-02	20181230*
/css/ie/css	2014-07-01	20131205*
/css/editor-blocks.css	2019-01-02	20181230*
Twenty Fifteen
style.css	2019-04-02	none
/css/blocks.css	2019-01-02	20181230*
/css/ie.css	2017-09-16	20141010*
/css/ie7.css	2014-12-10	20141010*
css/edtior-blocks.css	2019-01-02	20181230*
Twenty Sixteen
style.css	2019-02-07	none
/css/blocks.css	2019-01-02	20181230*
/css/ie8.css	2017-05-30	20160816*
/css/ie7.css	2017-05-30	20160816*
/css/editor-blocks.css	2019-01-02	20181230*
Twenty Seventeen
style.css	2019-04-08	none
/assets/css/blocks.css	2019-01-05	1.1
/assets/css/colors-dark.css	2019-04-08	1.0
/assets/css/ie9.css	2016-12-02	1.0
/assets/css/ie8.css	2016-12-02	1.0
/assets/css/editor-blocks.css	2019-03-28	1.1

Added during DEV

Twenty Sixteen
/css/ie.css	2017-05-30	20160816*

[dswebsme]

Replying to afercia:

[dswebsme]

Replying to afercia:

Thanks! I was just about to correct my markdown.

[dswebsme]

Patch attached.

This patch addresses stylesheet version issues originally reported by @desrosj in bundled themes twentyten - twentyseventeen. The following improvements are included:

• applies YYYYMMDD formatted version to stylesheets previously loaded without a version
• updates outdated file versions based on last modified date in the repository
• corrects version strings to match the preferred format of YYYYMMDD

Tapping @obenland and @ianbelanger as developers involved in the original discussion.

[superpoincare]

If there's a child theme, this won't work.

This is because the main stylesheet enqueued in parent functions.php is the child stylesheet.

The last modified date of the file is user dependent.

[dswebsme]

@superpoincare This is not meant to be a solution for child themes. As discussed in #39997, child themes with specific versioning requirements should be enqueueing stylesheets with their own custom version strings.

Specifically @obenland summed up our discussion here: https://core.trac.wordpress.org/ticket/39997#comment:37

[afercia]

Related: #46981.

[ianbelanger]

Changing milestone as Bundled Themes are only updated during major releases. Also removed version 5.1.1 as this was not introduced in that version.

[ianbelanger]

Since the release of 5.2 each themes style.css has been updated, so I am updating the table of Theme versions and will be updating the patch with the new dates.

	Last Modified	Current Specified Version
Twenty Ten
blocks.css	2018-12-18	20181018*
editor-blocks.css	2018-12-18	none
style.css	2019-05-07	none
Twenty Eleven
blocks.css	2019-01-02	20181230*
editor-blocks.css	2019-01-02	20181230*
style.css	2019-05-07	none
/inc/theme-options.css	2011-06-02	2011-04-28*
/colors/dark.css	2019-04-04	null*
Twenty Twelve
style.css	2019-05-07	none
/css/blocks.css	2019-04-06	20181230*
/css/ie.css	2015-02-14	20121010*
/css/editor-blocks.css	2019-04-06	20181230*
Twenty Thirteen
style.css	2019-05-07	2013-07-18*
/css/blocks.css	2019-01-02	2018-12-30*
/css/ie.css	2015-02-14	2013-07-18*
/css/editor-blocks.css	2019-01-02	2018-12-30*
Twenty Fourteen
style.css	2019-05-07	none
/css/blocks.css	2019-01-02	20181230*
/css/ie/css	2014-07-01	20131205*
/css/editor-blocks.css	2019-01-02	20181230*
Twenty Fifteen
style.css	2019-05-07	none
/css/blocks.css	2019-01-02	20181230*
/css/ie.css	2017-09-16	20141010*
/css/ie7.css	2014-12-10	20141010*
css/edtior-blocks.css	2019-01-02	20181230*
Twenty Sixteen
style.css	2019-05-07	none
/css/blocks.css	2019-01-02	20181230*
/css/ie8.css	2017-05-30	20160816*
/css/ie7.css	2017-05-30	20160816*
/css/editor-blocks.css	2019-01-02	20181230*
Twenty Seventeen
style.css	2019-05-07	none
/assets/css/blocks.css	2019-01-05	1.1
/assets/css/colors-dark.css	2019-04-08	1.0
/assets/css/ie9.css	2016-12-02	1.0
/assets/css/ie8.css	2016-12-02	1.0
/assets/css/editor-blocks.css	2019-03-28	1.1

[ianbelanger]

Updates patch with most recent updated dates for version numbers

[SergeyBiryukov]

In 45767:

Bundled Themes: Audit and update version numbers passed to wp_enqueue_style() to ensure proper cache busting.

Props dswebsme, ianbelanger, desrosj.
Fixes #46979.