test-trac-32103.sh

#!/bin/bash
if [ -z "$CURL_COOKIES" ]; then
	echo "Define a CURL_COOKIES environment variable containing the auth cookies for curl"
	echo "For example, invoke via:"
	echo "CURL_COOKIES='wordpress_test_cookie=WP+Cookie+check; wordpress_logged_in_abc123=...' $0"
	exit 1
fi
if [ -z "$CURL_NONCE" ]; then
	echo "Define a CURL_NONCE environment variable containing the nonce for the Customizer prevew"
	echo "For example, invoke via:"
	echo "CURL_NONCE='abc123' $0"
	exit 1
fi

make_dirty=false
ensure_option_added=false
while [[ $# > 0 ]]; do
	key="$1"
	case $key in
		--make_dirty|--make-dirty|--dirty)
			make_dirty=true
			;;
		--ensure_option_added|--ensure-option-added|--add_option|add-option)
			ensure_option_added=true
			;;
		*)
			# unknown option
			;;
	esac
	shift # past argument or value
done

echo "add_option:$ensure_option_added, dirty:$make_dirty" 1>&2

TIMEFORMAT=%R
for i in $( seq 0 20 ); do
	setting_count=$( expr $i \* 50 );
	url="http://src.wordpress-develop.dev/?setting_count=$setting_count"
	if [[ true == $make_dirty ]]; then
		url="$url&make_dirty=true"
	fi
	if [[ true == $ensure_option_added ]]; then
		url="$url&ensure_option_added=true"
	fi
	echo -n -e "$setting_count\t"
	time curl "$url" -s \
		-H 'Pragma: no-cache' \
		-H 'Origin: http://src.wordpress-develop.dev' \
		-H 'Accept-Encoding: gzip, deflate' \
		-H 'Accept-Language: en-US,en;q=0.8' \
		-H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36' \
		-H 'Content-Type: application/x-www-form-urlencoded; charset=UTF-8' \
		-H 'Accept: */*' -H 'Cache-Control: no-cache' \
		-H 'X-Requested-With: XMLHttpRequest' \
		-H "Cookie: $CURL_COOKIES" \
		-H 'Connection: keep-alive' \
		-H 'Referer: http://src.wordpress-develop.dev/wp-admin/customize.php?url=http%3A%2F%2Fsrc.wordpress-develop.dev%2F' \
		--data 'wp_customize=on&theme=twentyfifteen&customized=%7B%7D&nonce='$CURL_NONCE'&customize_messenger_channel=preview-0' \
		-o /dev/null --compressed 2>&1 | awk '{print $1}'
done

trac-32103.php

<?php
/**
 * Plugin Name: Tests for Trac 32103
 * Author: Weston Ruter, XWP
 */

define( 'TRAC_32103_SETTING_ID_BASE', 'trac_32103' );
define( 'TRAC_32103_MAX_SETTINGS', 1000 );

$default_root_values = array();
for ( $i = 1; $i <= TRAC_32103_MAX_SETTINGS; $i += 1 ) {
	$default_root_values[ "setting_$i" ] = array( 'l1' => array( 'l2' => array( 'l3' => $i ) ) );
}

add_action( 'customize_register', function( \WP_Customize_Manager $manager ) use ( $default_root_values ) {
	$preview_url = $manager->get_preview_url();
	if ( isset( $_REQUEST['ensure_option_added'] ) && 'true' === $_REQUEST['ensure_option_added'] ) {
		add_option( TRAC_32103_SETTING_ID_BASE, $default_root_values, '', 'no' );
		$preview_url = add_query_arg( 'ensure_option_added', 'true', $preview_url );
	}
	$setting_count = 0;
	if ( isset( $_REQUEST['setting_count'] ) ) {
		$setting_count = min( absint( $_REQUEST['setting_count'] ), TRAC_32103_MAX_SETTINGS );
		$preview_url = add_query_arg( 'setting_count', $setting_count, $preview_url );
	}
	$make_dirty = false;
	if ( isset( $_REQUEST['make_dirty'] ) && 'true' === $_REQUEST['make_dirty'] ) {
		$make_dirty = true;
		$preview_url = add_query_arg( 'make_dirty', 'true', $preview_url );
	}

	$manager->set_preview_url( $preview_url );
	if ( 0 === $setting_count ) {
		return;
	}

	$manager->add_section( 'trac-32103', array(
		'title' => 'Trac 32103',
	) );

	$added_count = 0;
	foreach ( $default_root_values as $key => $value ) {
		if ( $added_count >= $setting_count ) {
			break;
		}

		$setting_id = TRAC_32103_SETTING_ID_BASE . "[$key][l1][l2][l3]";
		$manager->add_setting( $setting_id, array(
			'type' => 'option',
			'sanitize_callback' => 'absint',
			'default' => $value['l1']['l2']['l3'],
		) );
		$setting = $manager->get_setting( $setting_id );
		$manager->add_control( $setting_id, array(
			'label' => $setting_id,
			'type' => 'number',
			'settings' => $setting_id,
			'section' => 'trac-32103',
		) );
		$added_count += 1;

		if ( $make_dirty ) {
			$setting->dirty = true;
			$manager->set_post_value( $setting_id, rand() );
		}
	}
} );

add_action( 'shutdown', function() {
	delete_option( TRAC_32103_SETTING_ID_BASE );
} );