Facilitate PHP versions in themes and plugins

[ryanve]

I want to propose a future-proof mechanism for safely allowing PHP 5.3+ in themes and plugins:

/**
 * Theme Name: example
 * Minimum PHP version: 5.3.0
 * ...
 */

Minimum version info could be used on the theme installation page to prevent 5.2- users from installing 5.3+ themes. The "Activate" link could be subdued or replaced with a link to inform the user that the theme needs a higher PHP version. Unspecified minimums would default to the ​WP requirement.

I initiated this discussion in the ​theme-reviewers list. Primary feedback there was to prevent breakage via graceful degradation or otherwise. The mechanism above is viable. ​Interim solutions are possible but less seamless.

Encouraging 5.3+ helps expedite ​user transition to 5.3+ and thus helps the core too.

[markoheijnen]

See #23880. To me this is something bad since it doesn't help a lot for people upgrading to 5.3 or higher. They probably go find another theme/plugin that does the same job.

[SergeyBiryukov]

Sounds like a duplicate of #23880 and #12260.