From c229cfccb49dd93ac050e27017c7d153e98ab618 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 08:04:54 +0200
Subject: [PATCH 01/22] handle general form requests around comment post logic

---
 amp.php                           |  5 +---
 includes/amp-helper-functions.php | 41 +++++++++++++++++++++++--------
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/amp.php b/amp.php
index b837d2a6efa..9ce15914401 100644
--- a/amp.php
+++ b/amp.php
@@ -106,7 +106,6 @@ function amp_after_setup_theme() {
  * @global string $pagenow
  */
 function amp_init() {
-	global $pagenow;
 
 	/**
 	 * Triggers on init when AMP plugin is active.
@@ -128,9 +127,7 @@ function amp_init() {
 	if ( class_exists( 'Jetpack' ) && ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) ) {
 		require_once AMP__DIR__ . '/jetpack-helper.php';
 	}
-	if ( isset( $pagenow ) && 'wp-comments-post.php' === $pagenow ) {
-		amp_prepare_comment_post();
-	}
+	amp_prepare_post();
 }
 
 // Make sure the `amp` query var has an explicit value.
diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 505a4d1d03e..9b9d6e474cd 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -238,22 +238,27 @@ function amp_get_content_sanitizers( $post = null ) {
 }
 
 /**
- * Hook into a comment submission of an AMP XHR post request.
- *
- * This only runs on wp-comments-post.php.
+ * Hook into a submission of an AMP XHR post request.
  *
  * @since 0.7.0
  */
-function amp_prepare_comment_post() {
-	if ( ! isset( $_GET['__amp_source_origin'] ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
+function amp_prepare_post() {
+	global $pagenow;
+	if ( ! isset( $_GET['__amp_source_origin'] ) || ! isset( $pagenow ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
 		return;
 	}
 
-	// Add amp comment hooks.
-	add_filter( 'comment_post_redirect', function() {
-		// We don't need any data, so just send a success.
-		wp_send_json_success();
-	}, PHP_INT_MAX, 2 );
+	if ( 'wp-comments-post.php' === $pagenow ) {
+		// This only runs on wp-comments-post.php.
+		add_filter( 'comment_post_redirect', function() {
+			// We don't need any data, so just send a success.
+			wp_send_json_success();
+		}, PHP_INT_MAX, 2 );
+
+	} else {
+		// Add amp comment hooks.
+		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
+	}
 
 	// Add die handler for AMP error display.
 	add_filter( 'wp_die_handler', function() {
@@ -275,4 +280,20 @@ function amp_prepare_comment_post() {
 	// Send AMP header.
 	$origin = esc_url_raw( wp_unslash( $_GET['__amp_source_origin'] ) ); // WPCS: CSRF ok.
 	header( 'AMP-Access-Control-Allow-Source-Origin: ' . $origin, true );
+
+}
+
+/**
+ * Handle a general, non comment AMP XHR post.
+ *
+ * @since 0.7.0
+ * @param string $location The location to redirect to.
+ */
+function amp_handle_general_post( $location ) {
+
+	$url = site_url( $location );
+	header( 'AMP-Redirect-To: ' . $url );
+	header( 'Access-Control-Expose-Headers: AMP-Redirect-To;' );
+	// Send json success.
+	wp_send_json_success();
 }

From 96c0bacb655c013643c77f91716c713679a9d1b1 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 08:47:46 +0200
Subject: [PATCH 02/22] record that action was converted to action-xhr and only
 handle converted submits.

---
 includes/amp-helper-functions.php                | 10 +++++-----
 includes/sanitizers/class-amp-form-sanitizer.php |  2 ++
 tests/test-amp-form-sanitizer.php                |  4 ++--
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 3a01c329d76..9355fd26c3e 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -418,11 +418,12 @@ function amp_prepare_post() {
 			// We don't need any data, so just send a success.
 			wp_send_json_success();
 		}, PHP_INT_MAX, 2 );
-
-	} else {
-		// Add amp comment hooks.
-		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
+	} elseif ( ! isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
+		// submission was from a set action-xhr, implying it's being handled already.
+		return;
 	}
+	// Add amp comment hooks.
+	add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
 
 	// Add die handler for AMP error display.
 	add_filter( 'wp_die_handler', function() {
@@ -444,7 +445,6 @@ function amp_prepare_post() {
 	// Send AMP header.
 	$origin = esc_url_raw( wp_unslash( $_GET['__amp_source_origin'] ) ); // WPCS: CSRF ok.
 	header( 'AMP-Access-Control-Allow-Source-Origin: ' . $origin, true );
-
 }
 
 /**
diff --git a/includes/sanitizers/class-amp-form-sanitizer.php b/includes/sanitizers/class-amp-form-sanitizer.php
index 2240906fa13..aba92e97c32 100644
--- a/includes/sanitizers/class-amp-form-sanitizer.php
+++ b/includes/sanitizers/class-amp-form-sanitizer.php
@@ -87,6 +87,8 @@ public function sanitize() {
 			} elseif ( 'post' === $method ) {
 				$node->removeAttribute( 'action' );
 				if ( ! $xhr_action ) {
+					// record that action was converted tp action-xhr.
+					$action_url = add_query_arg( '_wp_amp_action_xhr_converted', 1, $action_url );
 					$node->setAttribute( 'action-xhr', $action_url );
 				} elseif ( 'http://' === substr( $xhr_action, 0, 7 ) ) {
 					$node->setAttribute( 'action-xhr', substr( $xhr_action, 5 ) );
diff --git a/tests/test-amp-form-sanitizer.php b/tests/test-amp-form-sanitizer.php
index c0674d2ea6e..6f80abd7d0b 100644
--- a/tests/test-amp-form-sanitizer.php
+++ b/tests/test-amp-form-sanitizer.php
@@ -46,7 +46,7 @@ public function get_data() {
 			),
 			'form_with_post_method_http_action_and_no_target' => array(
 				'<form method="post" action="http://example.org/example-page/"></form>',
-				'<form method="post" action-xhr="//example.org/example-page/" target="_top"></form>',
+				'<form method="post" action-xhr="//example.org/example-page/?_wp_amp_action_xhr_converted=1" target="_top"></form>',
 			),
 			'form_with_post_method_http_action_and_blank_target' => array(
 				'<form method="post" action-xhr="http://example.org/example-page/" target="_blank"></form>',
@@ -58,7 +58,7 @@ public function get_data() {
 			),
 			'form_with_post_method_https_action_and_custom_target' => array(
 				'<form method="post" action="https://example.org/" target="some_other_target"></form>',
-				'<form method="post" target="_blank" action-xhr="https://example.org/"></form>',
+				'<form method="post" target="_blank" action-xhr="https://example.org/?_wp_amp_action_xhr_converted=1"></form>',
 			),
 		);
 	}

From 024d4e0886b43be802fbf1141f9528e154102b0b Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 08:54:08 +0200
Subject: [PATCH 03/22] rename function to be less ambiguous

---
 amp.php                           | 2 +-
 includes/amp-helper-functions.php | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/amp.php b/amp.php
index 9ce15914401..9daa2d75c25 100644
--- a/amp.php
+++ b/amp.php
@@ -127,7 +127,7 @@ function amp_init() {
 	if ( class_exists( 'Jetpack' ) && ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) ) {
 		require_once AMP__DIR__ . '/jetpack-helper.php';
 	}
-	amp_prepare_post();
+	amp_prepare_xhr_post();
 }
 
 // Make sure the `amp` query var has an explicit value.
diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 9355fd26c3e..2d35fa263b4 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -406,7 +406,7 @@ function amp_print_schemaorg_metadata() {
  *
  * @since 0.7.0
  */
-function amp_prepare_post() {
+function amp_prepare_xhr_post() {
 	global $pagenow;
 	if ( ! isset( $_GET['__amp_source_origin'] ) || ! isset( $pagenow ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
 		return;

From 967a8c64a0620faf71e11c3e20fb95db6445a89d Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 08:55:31 +0200
Subject: [PATCH 04/22] dont add wp_redirect filter on comment-handler

---
 includes/amp-helper-functions.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 2d35fa263b4..1630a62b3b3 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -421,10 +421,10 @@ function amp_prepare_xhr_post() {
 	} elseif ( ! isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
 		// submission was from a set action-xhr, implying it's being handled already.
 		return;
+	} else {
+		// Add amp comment hooks.
+		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
 	}
-	// Add amp comment hooks.
-	add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
-
 	// Add die handler for AMP error display.
 	add_filter( 'wp_die_handler', function() {
 		/**

From 4b259df89e5621db30c45b26bd5914abb25b3b83 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 10:12:10 +0200
Subject: [PATCH 05/22] add appending error template for converted forms

---
 .../sanitizers/class-amp-form-sanitizer.php   | 41 +++++++++++++++++++
 tests/test-amp-form-sanitizer.php             |  4 +-
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/includes/sanitizers/class-amp-form-sanitizer.php b/includes/sanitizers/class-amp-form-sanitizer.php
index aba92e97c32..0e118a2f184 100644
--- a/includes/sanitizers/class-amp-form-sanitizer.php
+++ b/includes/sanitizers/class-amp-form-sanitizer.php
@@ -90,6 +90,8 @@ public function sanitize() {
 					// record that action was converted tp action-xhr.
 					$action_url = add_query_arg( '_wp_amp_action_xhr_converted', 1, $action_url );
 					$node->setAttribute( 'action-xhr', $action_url );
+					// Append error handler if not found.
+					$this->error_handler( $node );
 				} elseif ( 'http://' === substr( $xhr_action, 0, 7 ) ) {
 					$node->setAttribute( 'action-xhr', substr( $xhr_action, 5 ) );
 				}
@@ -110,4 +112,43 @@ public function sanitize() {
 			}
 		}
 	}
+
+	/**
+	 * Checks if the form has an error handler else create one if not.
+	 *
+	 * @link https://www.ampproject.org/docs/reference/components/amp-form
+	 * @since 0.7
+	 * @param DOMElement $node The form node to check.
+	 */
+	public function error_handler( $node ) {
+		$templates = $node->getElementsByTagName( 'template' );
+		if ( $templates->length ) {
+			for ( $i = $templates->length - 1; $i >= 0; $i-- ) {
+				if ( $templates->item( $i )->parentNode->hasAttribute( 'submit-error' ) ) {
+					return; // Found error template, do nothing.
+				}
+			}
+		}
+		$node->appendChild( $this->create_error_template() );
+	}
+
+	/**
+	 * Creates a error handler element node.
+	 *
+	 * @link https://www.ampproject.org/docs/reference/components/amp-form
+	 * @since 0.7
+	 *
+	 * return DOMElement
+	 */
+	public function create_error_template() {
+		$node     = $this->dom->createElement( 'div' );
+		$template = $this->dom->createElement( 'template' );
+		$mustache = $this->dom->createTextNode( '{{{error}}}' );
+		$node->setAttribute( 'submit-error', '' );
+		$template->setAttribute( 'type', 'amp-mustache' );
+		$template->appendChild( $mustache );
+		$node->appendChild( $template );
+
+		return $node;
+	}
 }
diff --git a/tests/test-amp-form-sanitizer.php b/tests/test-amp-form-sanitizer.php
index 6f80abd7d0b..071931eeaee 100644
--- a/tests/test-amp-form-sanitizer.php
+++ b/tests/test-amp-form-sanitizer.php
@@ -46,7 +46,7 @@ public function get_data() {
 			),
 			'form_with_post_method_http_action_and_no_target' => array(
 				'<form method="post" action="http://example.org/example-page/"></form>',
-				'<form method="post" action-xhr="//example.org/example-page/?_wp_amp_action_xhr_converted=1" target="_top"></form>',
+				'<form method="post" action-xhr="//example.org/example-page/?_wp_amp_action_xhr_converted=1" target="_top"><div submit-error=""><template type="amp-mustache">{{{error}}}</template></div></form>',
 			),
 			'form_with_post_method_http_action_and_blank_target' => array(
 				'<form method="post" action-xhr="http://example.org/example-page/" target="_blank"></form>',
@@ -58,7 +58,7 @@ public function get_data() {
 			),
 			'form_with_post_method_https_action_and_custom_target' => array(
 				'<form method="post" action="https://example.org/" target="some_other_target"></form>',
-				'<form method="post" target="_blank" action-xhr="https://example.org/?_wp_amp_action_xhr_converted=1"></form>',
+				'<form method="post" target="_blank" action-xhr="https://example.org/?_wp_amp_action_xhr_converted=1"><div submit-error=""><template type="amp-mustache">{{{error}}}</template></div></form>',
 			),
 		);
 	}

From ac86bf2c72effb4489b948a28344f4181931052d Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 10:13:16 +0200
Subject: [PATCH 06/22] redirect page if redirect-template hits

---
 includes/amp-helper-functions.php    | 8 ++++++++
 includes/class-amp-theme-support.php | 3 ++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 1630a62b3b3..0e90b4b1796 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -424,6 +424,14 @@ function amp_prepare_xhr_post() {
 	} else {
 		// Add amp comment hooks.
 		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
+		add_action( 'template_redirect', function() {
+			/*
+			 * Buffering starts here, so unlikely the form has a redirect,
+			 * so force a redirect to the same page.
+			 */
+			$location = esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ); // WPCS: CSRF ok, input var ok.
+			amp_handle_general_post( $location );
+		}, 0 );
 	}
 	// Add die handler for AMP error display.
 	add_filter( 'wp_die_handler', function() {
diff --git a/includes/class-amp-theme-support.php b/includes/class-amp-theme-support.php
index 92c3646f3d7..407401a951f 100644
--- a/includes/class-amp-theme-support.php
+++ b/includes/class-amp-theme-support.php
@@ -102,7 +102,7 @@ public static function init() {
 			self::register_paired_hooks();
 		}
 
-		self::purge_amp_query_vars(); // Note that amp_prepare_comment_post() still looks at $_GET['__amp_source_origin'].
+		self::purge_amp_query_vars(); // Note that amp_prepare_xhr_post() still looks at $_GET['__amp_source_origin'].
 		self::register_hooks();
 		self::$embed_handlers    = self::register_content_embed_handlers();
 		self::$sanitizer_classes = amp_get_content_sanitizers();
@@ -214,6 +214,7 @@ public static function register_hooks() {
 	public static function purge_amp_query_vars() {
 		$query_vars = array(
 			'__amp_source_origin',
+			'_wp_amp_action_xhr_converted',
 			'amp_latest_update_time',
 		);
 

From eca4789491b2c7cc2b887efb02d0d8c3905b6398 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Thu, 1 Feb 2018 10:17:46 +0200
Subject: [PATCH 07/22] update docs

---
 includes/amp-helper-functions.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 0e90b4b1796..6071fd4bcba 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -422,7 +422,7 @@ function amp_prepare_xhr_post() {
 		// submission was from a set action-xhr, implying it's being handled already.
 		return;
 	} else {
-		// Add amp comment hooks.
+		// Add amp redirect hooks.
 		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
 		add_action( 'template_redirect', function() {
 			/*
@@ -466,6 +466,6 @@ function amp_handle_general_post( $location ) {
 	$url = site_url( $location );
 	header( 'AMP-Redirect-To: ' . $url );
 	header( 'Access-Control-Expose-Headers: AMP-Redirect-To;' );
-	// Send json success.
+	// Send json success as no data is required.
 	wp_send_json_success();
 }

From 9c965ad9ac0482dfc2ba6a792415417fffc43de2 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:05:00 +0200
Subject: [PATCH 08/22] rename handler function

---
 amp.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/amp.php b/amp.php
index 9daa2d75c25..0acc2bfa9c9 100644
--- a/amp.php
+++ b/amp.php
@@ -127,7 +127,7 @@ function amp_init() {
 	if ( class_exists( 'Jetpack' ) && ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) ) {
 		require_once AMP__DIR__ . '/jetpack-helper.php';
 	}
-	amp_prepare_xhr_post();
+	amp_handle_xhr_request();
 }
 
 // Make sure the `amp` query var has an explicit value.

From 83a0799235a36876a0dbc4369b0fedfe8435845e Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:10:24 +0200
Subject: [PATCH 09/22] simplify handler function

---
 includes/amp-helper-functions.php | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 6071fd4bcba..9fd42acbaf2 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -406,7 +406,7 @@ function amp_print_schemaorg_metadata() {
  *
  * @since 0.7.0
  */
-function amp_prepare_xhr_post() {
+function amp_handle_xhr_request() {
 	global $pagenow;
 	if ( ! isset( $_GET['__amp_source_origin'] ) || ! isset( $pagenow ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
 		return;
@@ -418,10 +418,8 @@ function amp_prepare_xhr_post() {
 			// We don't need any data, so just send a success.
 			wp_send_json_success();
 		}, PHP_INT_MAX, 2 );
-	} elseif ( ! isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
-		// submission was from a set action-xhr, implying it's being handled already.
-		return;
-	} else {
+		amp_handle_xhr_headers_output();
+	} elseif ( isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
 		// Add amp redirect hooks.
 		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
 		add_action( 'template_redirect', function() {
@@ -432,7 +430,17 @@ function amp_prepare_xhr_post() {
 			$location = esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ); // WPCS: CSRF ok, input var ok.
 			amp_handle_general_post( $location );
 		}, 0 );
+		amp_handle_xhr_headers_output();
 	}
+
+}
+
+/**
+ * Handle the AMP XHR headers and output errors.
+ *
+ * @since 0.7.0
+ */
+function amp_handle_xhr_headers_output() {
 	// Add die handler for AMP error display.
 	add_filter( 'wp_die_handler', function() {
 		/**

From 09de4203fb46ac92494af820c16853225ff59886 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:19:54 +0200
Subject: [PATCH 10/22] correct phpdoc return tag

---
 includes/sanitizers/class-amp-form-sanitizer.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/includes/sanitizers/class-amp-form-sanitizer.php b/includes/sanitizers/class-amp-form-sanitizer.php
index 0e118a2f184..7937d6f16fc 100644
--- a/includes/sanitizers/class-amp-form-sanitizer.php
+++ b/includes/sanitizers/class-amp-form-sanitizer.php
@@ -138,7 +138,7 @@ public function error_handler( $node ) {
 	 * @link https://www.ampproject.org/docs/reference/components/amp-form
 	 * @since 0.7
 	 *
-	 * return DOMElement
+	 * @return DOMElement The div[submit-error] element.
 	 */
 	public function create_error_template() {
 		$node     = $this->dom->createElement( 'div' );

From 40934c1cbbb54aa3ed0c0e4c212bb3512e69592b Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:21:44 +0200
Subject: [PATCH 11/22] update @link with correct url

---
 includes/sanitizers/class-amp-form-sanitizer.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/includes/sanitizers/class-amp-form-sanitizer.php b/includes/sanitizers/class-amp-form-sanitizer.php
index 7937d6f16fc..c3cdfe437b1 100644
--- a/includes/sanitizers/class-amp-form-sanitizer.php
+++ b/includes/sanitizers/class-amp-form-sanitizer.php
@@ -116,7 +116,7 @@ public function sanitize() {
 	/**
 	 * Checks if the form has an error handler else create one if not.
 	 *
-	 * @link https://www.ampproject.org/docs/reference/components/amp-form
+	 * @link https://www.ampproject.org/docs/reference/components/amp-form#success/error-response-rendering
 	 * @since 0.7
 	 * @param DOMElement $node The form node to check.
 	 */
@@ -135,7 +135,7 @@ public function error_handler( $node ) {
 	/**
 	 * Creates a error handler element node.
 	 *
-	 * @link https://www.ampproject.org/docs/reference/components/amp-form
+	 * @link https://www.ampproject.org/docs/reference/components/amp-form#success/error-response-rendering
 	 * @since 0.7
 	 *
 	 * @return DOMElement The div[submit-error] element.

From 6dd4e9d1e37056d202bad75e68a9568c46d46a6f Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:23:29 +0200
Subject: [PATCH 12/22] rename redirect function

---
 includes/amp-helper-functions.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 9fd42acbaf2..34ea9e2daac 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -421,7 +421,7 @@ function amp_handle_xhr_request() {
 		amp_handle_xhr_headers_output();
 	} elseif ( isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
 		// Add amp redirect hooks.
-		add_filter( 'wp_redirect', 'amp_handle_general_post', PHP_INT_MAX, 2 );
+		add_filter( 'wp_redirect', 'amp_intercept_post_request_redirect', PHP_INT_MAX, 2 );
 		add_action( 'template_redirect', function() {
 			/*
 			 * Buffering starts here, so unlikely the form has a redirect,
@@ -469,7 +469,7 @@ function amp_handle_xhr_headers_output() {
  * @since 0.7.0
  * @param string $location The location to redirect to.
  */
-function amp_handle_general_post( $location ) {
+function amp_intercept_post_request_redirect( $location ) {
 
 	$url = site_url( $location );
 	header( 'AMP-Redirect-To: ' . $url );

From a9d9bfdad23693eef28001e6b975f2df9cdf2ea6 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:26:59 +0200
Subject: [PATCH 13/22] catch  data for redirection and reload inclusion
 hackery

---
 includes/amp-helper-functions.php | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 34ea9e2daac..93109809304 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -408,6 +408,14 @@ function amp_print_schemaorg_metadata() {
  */
 function amp_handle_xhr_request() {
 	global $pagenow;
+	if ( isset( $_GET['__amp_redirect'] ) ) { // WPCS: CSRF ok.
+		add_action( 'template_redirect', function() {
+			// grab post data.
+			$transint_name = wp_unslash( $_GET['__amp_redirect'] ); // WPCS: CSRF ok, input var ok.
+			$_POST         = get_transient( $transint_name );
+			delete_transient( $transint_name );
+		}, 0 );
+	}
 	if ( ! isset( $_GET['__amp_source_origin'] ) || ! isset( $pagenow ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
 		return;
 	}
@@ -423,12 +431,17 @@ function amp_handle_xhr_request() {
 		// Add amp redirect hooks.
 		add_filter( 'wp_redirect', 'amp_intercept_post_request_redirect', PHP_INT_MAX, 2 );
 		add_action( 'template_redirect', function() {
+			// grab post data.
+			$transient_name = uniqid();
+			set_transient( $transient_name, wp_unslash( $_POST ), 60 ); // WPCS: CSRF ok, input var ok.
+
 			/*
 			 * Buffering starts here, so unlikely the form has a redirect,
 			 * so force a redirect to the same page.
 			 */
 			$location = esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ); // WPCS: CSRF ok, input var ok.
-			amp_handle_general_post( $location );
+			$location = add_query_arg( '__amp_redirect', $transient_name, $location );
+			amp_intercept_post_request_redirect( $location );
 		}, 0 );
 		amp_handle_xhr_headers_output();
 	}

From 17ab3fd5ff7ce3fad95d863c58e07a259cc6ba7e Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Fri, 2 Feb 2018 07:36:53 +0200
Subject: [PATCH 14/22] check redirect location has a host first

---
 includes/amp-helper-functions.php | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 93109809304..1f8cdb911a3 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -483,9 +483,11 @@ function amp_handle_xhr_headers_output() {
  * @param string $location The location to redirect to.
  */
 function amp_intercept_post_request_redirect( $location ) {
-
-	$url = site_url( $location );
-	header( 'AMP-Redirect-To: ' . $url );
+	$host = wp_parse_url( $location, PHP_URL_HOST );
+	if ( is_null( $host ) ) {
+		$location = home_url( $location );
+	}
+	header( 'AMP-Redirect-To: ' . $location );
 	header( 'Access-Control-Expose-Headers: AMP-Redirect-To;' );
 	// Send json success as no data is required.
 	wp_send_json_success();

From 92f3a761236553ef09584c12d81bb3d1a68f3029 Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 2 Feb 2018 14:26:42 -0800
Subject: [PATCH 15/22] Allow all formatting tags to be returned in submit
 error response

---
 includes/amp-helper-functions.php | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index 1f8cdb911a3..bf25bd7ec4d 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -466,8 +466,10 @@ function amp_handle_xhr_headers_output() {
 			if ( is_wp_error( $error ) ) {
 				$error = $error->get_error_message();
 			}
-			$error = strip_tags( $error, 'strong' );
-			wp_send_json( compact( 'error' ) );
+			$amp_mustache_allowed_html_tags = array( 'strong', 'b', 'em', 'i', 'u', 's', 'small', 'mark', 'del', 'ins', 'sup', 'sub' );
+			wp_send_json( array(
+				'error' => wp_kses( $error, array_fill_keys( $amp_mustache_allowed_html_tags, array() ) ),
+			) );
 		};
 	} );
 

From 1593f882256d6d835db9a0e73ec9d0128f297a8c Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 2 Feb 2018 14:33:01 -0800
Subject: [PATCH 16/22] Remove support for handling non-redirecting post
 requests, for now

---
 includes/amp-helper-functions.php             | 31 ++--------------
 .../sanitizers/class-amp-form-sanitizer.php   | 37 ++++++-------------
 2 files changed, 16 insertions(+), 52 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index bf25bd7ec4d..fc09db8580d 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -400,27 +400,18 @@ function amp_print_schemaorg_metadata() {
 }
 
 /**
- * Hook into a comment submission of an AMP XHR post request.
- *
- * This only runs on wp-comments-post.php.
+ * Hook into a form submissions, such as comment the form or some other .
  *
  * @since 0.7.0
+ * @global string $pagenow
  */
 function amp_handle_xhr_request() {
 	global $pagenow;
-	if ( isset( $_GET['__amp_redirect'] ) ) { // WPCS: CSRF ok.
-		add_action( 'template_redirect', function() {
-			// grab post data.
-			$transint_name = wp_unslash( $_GET['__amp_redirect'] ); // WPCS: CSRF ok, input var ok.
-			$_POST         = get_transient( $transint_name );
-			delete_transient( $transint_name );
-		}, 0 );
-	}
-	if ( ! isset( $_GET['__amp_source_origin'] ) || ! isset( $pagenow ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
+	if ( ! isset( $_GET['__amp_source_origin'] ) ) { // WPCS: CSRF ok. Beware of AMP_Theme_Support::purge_amp_query_vars().
 		return;
 	}
 
-	if ( 'wp-comments-post.php' === $pagenow ) {
+	if ( isset( $pagenow ) && 'wp-comments-post.php' === $pagenow ) {
 		// This only runs on wp-comments-post.php.
 		add_filter( 'comment_post_redirect', function() {
 			// We don't need any data, so just send a success.
@@ -428,21 +419,7 @@ function amp_handle_xhr_request() {
 		}, PHP_INT_MAX, 2 );
 		amp_handle_xhr_headers_output();
 	} elseif ( isset( $_GET['_wp_amp_action_xhr_converted'] ) ) { // WPCS: CSRF ok.
-		// Add amp redirect hooks.
 		add_filter( 'wp_redirect', 'amp_intercept_post_request_redirect', PHP_INT_MAX, 2 );
-		add_action( 'template_redirect', function() {
-			// grab post data.
-			$transient_name = uniqid();
-			set_transient( $transient_name, wp_unslash( $_POST ), 60 ); // WPCS: CSRF ok, input var ok.
-
-			/*
-			 * Buffering starts here, so unlikely the form has a redirect,
-			 * so force a redirect to the same page.
-			 */
-			$location = esc_url_raw( wp_unslash( $_SERVER['REQUEST_URI'] ) ); // WPCS: CSRF ok, input var ok.
-			$location = add_query_arg( '__amp_redirect', $transient_name, $location );
-			amp_intercept_post_request_redirect( $location );
-		}, 0 );
 		amp_handle_xhr_headers_output();
 	}
 
diff --git a/includes/sanitizers/class-amp-form-sanitizer.php b/includes/sanitizers/class-amp-form-sanitizer.php
index c3cdfe437b1..05c6252f0cc 100644
--- a/includes/sanitizers/class-amp-form-sanitizer.php
+++ b/includes/sanitizers/class-amp-form-sanitizer.php
@@ -91,7 +91,7 @@ public function sanitize() {
 					$action_url = add_query_arg( '_wp_amp_action_xhr_converted', 1, $action_url );
 					$node->setAttribute( 'action-xhr', $action_url );
 					// Append error handler if not found.
-					$this->error_handler( $node );
+					$this->ensure_submit_error_element( $node );
 				} elseif ( 'http://' === substr( $xhr_action, 0, 7 ) ) {
 					$node->setAttribute( 'action-xhr', substr( $xhr_action, 5 ) );
 				}
@@ -118,37 +118,24 @@ public function sanitize() {
 	 *
 	 * @link https://www.ampproject.org/docs/reference/components/amp-form#success/error-response-rendering
 	 * @since 0.7
-	 * @param DOMElement $node The form node to check.
+	 *
+	 * @param DOMElement $form The form node to check.
 	 */
-	public function error_handler( $node ) {
-		$templates = $node->getElementsByTagName( 'template' );
-		if ( $templates->length ) {
-			for ( $i = $templates->length - 1; $i >= 0; $i-- ) {
-				if ( $templates->item( $i )->parentNode->hasAttribute( 'submit-error' ) ) {
-					return; // Found error template, do nothing.
-				}
+	public function ensure_submit_error_element( $form ) {
+		$templates = $form->getElementsByTagName( 'template' );
+		for ( $i = $templates->length - 1; $i >= 0; $i-- ) {
+			if ( $templates->item( $i )->parentNode->hasAttribute( 'submit-error' ) ) {
+				return; // Found error template, do nothing.
 			}
 		}
-		$node->appendChild( $this->create_error_template() );
-	}
 
-	/**
-	 * Creates a error handler element node.
-	 *
-	 * @link https://www.ampproject.org/docs/reference/components/amp-form#success/error-response-rendering
-	 * @since 0.7
-	 *
-	 * @return DOMElement The div[submit-error] element.
-	 */
-	public function create_error_template() {
-		$node     = $this->dom->createElement( 'div' );
+		$div      = $this->dom->createElement( 'div' );
 		$template = $this->dom->createElement( 'template' );
 		$mustache = $this->dom->createTextNode( '{{{error}}}' );
-		$node->setAttribute( 'submit-error', '' );
+		$div->setAttribute( 'submit-error', '' );
 		$template->setAttribute( 'type', 'amp-mustache' );
 		$template->appendChild( $mustache );
-		$node->appendChild( $template );
-
-		return $node;
+		$div->appendChild( $template );
+		$form->appendChild( $div );
 	}
 }

From 3791cd8b54a0a7851a4b002e56773c490f2ed68d Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Fri, 2 Feb 2018 15:01:57 -0800
Subject: [PATCH 17/22] Ensure relative redirect URLs get made absolute for AMP

---
 includes/amp-helper-functions.php | 34 +++++++++++++++++++++++--------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/includes/amp-helper-functions.php b/includes/amp-helper-functions.php
index fc09db8580d..4694b6953ce 100644
--- a/includes/amp-helper-functions.php
+++ b/includes/amp-helper-functions.php
@@ -412,7 +412,7 @@ function amp_handle_xhr_request() {
 	}
 
 	if ( isset( $pagenow ) && 'wp-comments-post.php' === $pagenow ) {
-		// This only runs on wp-comments-post.php.
+		// We don't need any data, so just send a success.
 		add_filter( 'comment_post_redirect', function() {
 			// We don't need any data, so just send a success.
 			wp_send_json_success();
@@ -422,7 +422,6 @@ function amp_handle_xhr_request() {
 		add_filter( 'wp_redirect', 'amp_intercept_post_request_redirect', PHP_INT_MAX, 2 );
 		amp_handle_xhr_headers_output();
 	}
-
 }
 
 /**
@@ -456,18 +455,37 @@ function amp_handle_xhr_headers_output() {
 }
 
 /**
- * Handle a general, non comment AMP XHR post.
+ * Intercept the response to a non-comment POST request.
  *
  * @since 0.7.0
  * @param string $location The location to redirect to.
  */
 function amp_intercept_post_request_redirect( $location ) {
-	$host = wp_parse_url( $location, PHP_URL_HOST );
-	if ( is_null( $host ) ) {
-		$location = home_url( $location );
+
+	// Make sure relative redirects get made absolute.
+	$parsed_location = array_merge(
+		array(
+			'scheme' => 'https',
+			'host'   => wp_parse_url( home_url(), PHP_URL_HOST ),
+			'path'   => strtok( wp_unslash( $_SERVER['REQUEST_URI'] ), '?' ),
+		),
+		wp_parse_url( $location )
+	);
+
+	$absolute_location = $parsed_location['scheme'] . '://' . $parsed_location['host'];
+	if ( isset( $parsed_location['port'] ) ) {
+		$absolute_location .= ':' . $parsed_location['port'];
+	}
+	$absolute_location .= $parsed_location['path'];
+	if ( isset( $parsed_location['query'] ) ) {
+		$absolute_location .= '?' . $parsed_location['query'];
 	}
-	header( 'AMP-Redirect-To: ' . $location );
-	header( 'Access-Control-Expose-Headers: AMP-Redirect-To;' );
+	if ( isset( $parsed_location['fragment'] ) ) {
+		$absolute_location .= '#' . $parsed_location['fragment'];
+	}
+
+	header( 'AMP-Redirect-To: ' . $absolute_location );
+	header( 'Access-Control-Expose-Headers: AMP-Redirect-To' );
 	// Send json success as no data is required.
 	wp_send_json_success();
 }

From 7a4b398a801e0fa6a475f60f588b5be14c6e4b4c Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Mon, 5 Feb 2018 16:14:45 +0200
Subject: [PATCH 18/22] add process isolation

---
 phpunit.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/phpunit.xml b/phpunit.xml
index a2b80c5bb36..625934afd4a 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,4 +1,5 @@
 <phpunit
+	processIsolation="true"
 	bootstrap="dev-lib/phpunit-plugin-bootstrap.php"
 	backupGlobals="false"
 	colors="true"

From d38f03eb19f98ec2f83e278f55393af9136d2a8c Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Mon, 5 Feb 2018 16:31:06 +0200
Subject: [PATCH 19/22] remove isolation tag

---
 phpunit.xml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/phpunit.xml b/phpunit.xml
index 625934afd4a..a2b80c5bb36 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,5 +1,4 @@
 <phpunit
-	processIsolation="true"
 	bootstrap="dev-lib/phpunit-plugin-bootstrap.php"
 	backupGlobals="false"
 	colors="true"

From 3b3b545e025160579d9cc85c1052029c65ae604d Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Tue, 6 Feb 2018 07:28:34 +0200
Subject: [PATCH 20/22] add test for amp_intercept_post_request_redirect

---
 tests/test-amp-helper-functions.php | 49 +++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/tests/test-amp-helper-functions.php b/tests/test-amp-helper-functions.php
index f7cde3d0e7a..f8b3bd4a5c9 100644
--- a/tests/test-amp-helper-functions.php
+++ b/tests/test-amp-helper-functions.php
@@ -362,4 +362,53 @@ public function test_amp_get_schemaorg_metadata() {
 		$this->assertArrayHasKey( 'did_amp_schemaorg_metadata', $metadata );
 		$this->assertEquals( 'George', $metadata['author']['name'] );
 	}
+
+	/**
+	 * Test amp_intercept_post_request_redirect().
+	 *
+	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
+	 * @group amp-submissions
+	 */
+	public function test_amp_intercept_post_request_redirect() {
+		if ( ! function_exists( 'xdebug_get_headers' ) ) {
+			$this->markTestSkipped( 'xdebug is required for this test' );
+		}
+
+		add_theme_support( 'amp' );
+		$url = get_home_url();
+
+		add_filter( 'wp_doing_ajax', '__return_true' );
+		add_filter( 'wp_die_ajax_handler', function () {
+			return '__return_false';
+		} );
+
+		ob_start();
+		amp_intercept_post_request_redirect( $url );
+		ob_get_clean();
+		$this->assertContains( 'AMP-Redirect-To: ' . $url, xdebug_get_headers() );
+		$this->assertContains( 'Access-Control-Expose-Headers: AMP-Redirect-To', xdebug_get_headers() );
+
+		ob_start();
+		amp_intercept_post_request_redirect( '/new-location/' );
+		ob_get_clean();
+		$this->assertContains( 'AMP-Redirect-To: https://example.org/new-location/', xdebug_get_headers() );
+
+		ob_start();
+		amp_intercept_post_request_redirect( '//example.com/new-location/' );
+		ob_get_clean();
+		$headers = xdebug_get_headers();
+		$this->assertContains( 'AMP-Redirect-To: https://example.com/new-location/', $headers );
+
+		ob_start();
+		amp_intercept_post_request_redirect( '' );
+		ob_get_clean();
+		$this->assertContains( 'AMP-Redirect-To: https://example.org', xdebug_get_headers() );
+
+		remove_filter( 'wp_doing_ajax', '__return_true' );
+		remove_filter( 'wp_die_ajax_handler', function () {
+			return '__return_false';
+		} );
+
+	}
 }

From 4090e4e52c05d90d076dcfc8518400dfdad952a5 Mon Sep 17 00:00:00 2001
From: David Cramer <david@digilab.co.za>
Date: Tue, 6 Feb 2018 07:48:17 +0200
Subject: [PATCH 21/22] add test for amp_handle_xhr_request

---
 tests/test-amp-helper-functions.php | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/tests/test-amp-helper-functions.php b/tests/test-amp-helper-functions.php
index f8b3bd4a5c9..bdd46354a44 100644
--- a/tests/test-amp-helper-functions.php
+++ b/tests/test-amp-helper-functions.php
@@ -368,7 +368,6 @@ public function test_amp_get_schemaorg_metadata() {
 	 *
 	 * @runInSeparateProcess
 	 * @preserveGlobalState disabled
-	 * @group amp-submissions
 	 */
 	public function test_amp_intercept_post_request_redirect() {
 		if ( ! function_exists( 'xdebug_get_headers' ) ) {
@@ -411,4 +410,25 @@ public function test_amp_intercept_post_request_redirect() {
 		} );
 
 	}
+
+	/**
+	 * Test amp_handle_xhr_request().
+	 *
+	 * @runInSeparateProcess
+	 * @preserveGlobalState disabled
+	 * @covers amp_handle_xhr_headers_output()
+	 */
+	public function test_amp_handle_xhr_request() {
+		global $pagenow;
+		if ( ! function_exists( 'xdebug_get_headers' ) ) {
+			$this->markTestSkipped( 'xdebug is required for this test' );
+		}
+
+		$_GET['__amp_source_origin'] = 'https://example.org';
+		$pagenow                     = 'wp-comments-post.php';
+
+		amp_handle_xhr_request();
+		$this->assertContains( 'AMP-Access-Control-Allow-Source-Origin: https://example.org', xdebug_get_headers() );
+
+	}
 }

From ee75de2759833f55c1bdf295fd2af746992eb83b Mon Sep 17 00:00:00 2001
From: Weston Ruter <weston@xwp.co>
Date: Tue, 6 Feb 2018 23:42:17 -0800
Subject: [PATCH 22/22] Augment amp_intercept_post_request_redirect test with
 checking output

---
 tests/test-amp-helper-functions.php | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/tests/test-amp-helper-functions.php b/tests/test-amp-helper-functions.php
index bdd46354a44..4eed7183a7f 100644
--- a/tests/test-amp-helper-functions.php
+++ b/tests/test-amp-helper-functions.php
@@ -368,6 +368,7 @@ public function test_amp_get_schemaorg_metadata() {
 	 *
 	 * @runInSeparateProcess
 	 * @preserveGlobalState disabled
+	 * @covers amp_intercept_post_request_redirect()
 	 */
 	public function test_amp_intercept_post_request_redirect() {
 		if ( ! function_exists( 'xdebug_get_headers' ) ) {
@@ -384,31 +385,26 @@ public function test_amp_intercept_post_request_redirect() {
 
 		ob_start();
 		amp_intercept_post_request_redirect( $url );
-		ob_get_clean();
+		$this->assertEquals( '{"success":true}', ob_get_clean() );
+
 		$this->assertContains( 'AMP-Redirect-To: ' . $url, xdebug_get_headers() );
 		$this->assertContains( 'Access-Control-Expose-Headers: AMP-Redirect-To', xdebug_get_headers() );
 
 		ob_start();
 		amp_intercept_post_request_redirect( '/new-location/' );
-		ob_get_clean();
+		$this->assertEquals( '{"success":true}', ob_get_clean() );
 		$this->assertContains( 'AMP-Redirect-To: https://example.org/new-location/', xdebug_get_headers() );
 
 		ob_start();
 		amp_intercept_post_request_redirect( '//example.com/new-location/' );
-		ob_get_clean();
+		$this->assertEquals( '{"success":true}', ob_get_clean() );
 		$headers = xdebug_get_headers();
 		$this->assertContains( 'AMP-Redirect-To: https://example.com/new-location/', $headers );
 
 		ob_start();
 		amp_intercept_post_request_redirect( '' );
-		ob_get_clean();
+		$this->assertEquals( '{"success":true}', ob_get_clean() );
 		$this->assertContains( 'AMP-Redirect-To: https://example.org', xdebug_get_headers() );
-
-		remove_filter( 'wp_doing_ajax', '__return_true' );
-		remove_filter( 'wp_die_ajax_handler', function () {
-			return '__return_false';
-		} );
-
 	}
 
 	/**