Rename wp_send_late_headers action to wp_finalized_template_enhancement_output_buffer

[westonruter]

Follow up to #10381 (r61088 / b482707).

See #10381 (comment)

Trac ticket: https://core.trac.wordpress.org/ticket/64126

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[dmsnell]

Without any strong feelings about the names, including the previous one, after stands out more clearly to me than finalized, and I think we can see some natural associations with it based on the way the documentation for the filter is worded.

There is nothing in here that jumps out as issues for concern.

[dmsnell]

this might be a comment for a discussion outside of this change, but does this stipulation apply to PHP code running inside the template generation too? I know various bits of code that use output buffering for small things, including block themes loading templates via include. If it’s a new default behavior that those snippets will now crash, we should make sure to communicate that in a Dev Note prominently.

[westonruter]

No, it doesn't apply to PHP code running inside the template generation. Otherwise, this would have been totally infeasible.

Nested output buffers are normal. It's just not allowed to open output buffers inside the callback for handling an output buffer.

[westonruter]

Without any strong feelings about the names, including the previous one, after stands out more clearly to me than finalized, and I think we can see some natural associations with it based on the way the documentation for the filter is worded.

@dmsnell Do you mean wp_finalized_template_enhancement_output_buffer is fine but you would prefer something that incorporated "after"?

There's wp_after_insert_post, wp_after_execute_ability, wp_after_admin_bar_render, and wp_after_load_template as precedent for that but there should then be a verb added after after, so like wp_after_finalize_template_enhancement_output_buffer? Oof. That's getting long.

Update: Clarified in Slack.

[westonruter]

Committed in r61111.