PHP 7.3 compatibility: using `continue` in `switch` statements

[jrf]

As of PHP 7.3, using continue to target a switch control structure will throw an E_WARNING.

Applying continue to a switch is equivalent to using break and quite possibly, a continue targeting a higher level control structure is actually intended.

To target the higher level control structure, a numeric argument has to be passed to continue.

Refs:

• ​http://php.net/manual/en/control-structures.continue.php
• ​https://github.com/php/php-src/pull/3364
• ​https://wiki.php.net/rfc/continue_on_switch_deprecation

This change has been recently committed to PHP itself and will break the build against nightly for the current master already.
See: ​https://travis-ci.org/WordPress/wordpress-develop/jobs/401538006#L828-L831.

The attached patch fixes the two instances of this in WordPress.

Notes:

• Both these switches are nested in other control structures, but end the switch at the scope closer of the outer control structure, so using break in these cases is equivalent to using continue 2.

---

FYI: The ​PHPCompatibility standard will include a sniff to detect this in the near future. This ticket is the result of some tests I've been running on the WIP PHPCompatibility sniff :wink:

[pento]

Patch looks good to me.

[kraftbj]

Bumping it to a minor release to ensure consideration for the next round. PHP 7.3 GA is scheduled for December 13th.

+1 on patch looking good.

[jorbin]

In 43653:

General: PHP7.3 throws an E_WARNING when using continue to target a switch

Applying continue to a switch is equivalent to using break and quite possibly, a continue targeting a higher level control structure is actually intended.

To target the higher level control structure, a numeric argument has to be passed to continue. This fixes two cases in WordPress Core where this is currently happening.

See: ​https://github.com/php/php-src/pull/3364
See: ​https://wiki.php.net/rfc/continue_on_switch_deprecation

Props jrf.
Fixes #44543.

[jorbin]

Reopening for consideration for 4.9.9

[jorbin]

#44944 was marked as a duplicate.

[SergeyBiryukov]

In 43656:

General: PHP 7.3 throws an E_WARNING when using continue to target a switch.

Applying continue to a switch is equivalent to using break and quite possibly, a continue targeting a higher level control structure is actually intended.

To target the higher level control structure, a numeric argument has to be passed to continue. This fixes two cases in WordPress Core where this is currently happening.

See: ​https://github.com/php/php-src/pull/3364
See: ​https://wiki.php.net/rfc/continue_on_switch_deprecation

Props jrf.
Merges [43653] to the 4.9 branch.
Fixes #44543.

[jrf]

Reopened as this needs to be ported to the 5.0 branch as well.

[SergeyBiryukov]

In 43746:

General: PHP 7.3 throws an E_WARNING when using continue to target a switch.

Applying continue to a switch is equivalent to using break and quite possibly, a continue targeting a higher level control structure is actually intended.

To target the higher level control structure, a numeric argument has to be passed to continue. This fixes two cases in WordPress Core where this is currently happening.

See: ​https://github.com/php/php-src/pull/3364
See: ​https://wiki.php.net/rfc/continue_on_switch_deprecation

Props jrf.
Merges [43653] to the 5.0 branch.
Fixes #44543.