From b487f99fc3680f10df6874d913636612bc771e9d Mon Sep 17 00:00:00 2001
From: Gary Pendergast <gary@pento.net>
Date: Mon, 23 Jul 2018 16:19:37 +1000
Subject: [PATCH 1/2] Allow ID attributes on any elements.

---
 packages/blocks/src/api/raw-handling/test/utils.js | 10 ++++++++--
 packages/blocks/src/api/raw-handling/utils.js      |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/blocks/src/api/raw-handling/test/utils.js b/packages/blocks/src/api/raw-handling/test/utils.js
index 2d83a9a25e4884..e7342a12fe30d3 100644
--- a/packages/blocks/src/api/raw-handling/test/utils.js
+++ b/packages/blocks/src/api/raw-handling/test/utils.js
@@ -109,14 +109,20 @@ describe( 'removeInvalidHTML', () => {
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
 
+	it( 'should keep id attributes', () => {
+		const input = '<p id="foo">test</p>';
+		const output = '<p id="foo">test</p>';
+		expect( removeInvalidHTML( input, schema ) ).toBe( output );
+	} );
+
 	it( 'should remove multiple attributes', () => {
-		const input = '<p class="test" id="test">test</p>';
+		const input = '<p class="test" style="test">test</p>';
 		const output = '<p>test</p>';
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
 
 	it( 'should deep remove attributes', () => {
-		const input = '<p class="test">test <em id="test">test</em></p>';
+		const input = '<p class="test">test <em style="test">test</em></p>';
 		const output = '<p>test <em>test</em></p>';
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
diff --git a/packages/blocks/src/api/raw-handling/utils.js b/packages/blocks/src/api/raw-handling/utils.js
index 9e7f093f3691a1..158b8fd9064a91 100644
--- a/packages/blocks/src/api/raw-handling/utils.js
+++ b/packages/blocks/src/api/raw-handling/utils.js
@@ -197,7 +197,7 @@ function cleanNodeList( nodeList, doc, schema, inline ) {
 				if ( node.hasAttributes() ) {
 					// Strip invalid attributes.
 					Array.from( node.attributes ).forEach( ( { name } ) => {
-						if ( name !== 'class' && ! includes( attributes, name ) ) {
+						if ( name !== 'class' && name !== 'id' && ! includes( attributes, name ) ) {
 							node.removeAttribute( name );
 						}
 					} );

From 98e418fca418914c25323edd8b59f023d61d9492 Mon Sep 17 00:00:00 2001
From: Gary Pendergast <gary@pento.net>
Date: Tue, 24 Jul 2018 14:18:21 +1000
Subject: [PATCH 2/2] Only allow blocks that support the anchor feature to keep
 their ID.

---
 .../blocks/src/api/raw-handling/test/utils.js    |  8 ++++----
 packages/blocks/src/api/raw-handling/utils.js    | 16 ++++++++++++++--
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/packages/blocks/src/api/raw-handling/test/utils.js b/packages/blocks/src/api/raw-handling/test/utils.js
index e7342a12fe30d3..dfa073a6e5a53a 100644
--- a/packages/blocks/src/api/raw-handling/test/utils.js
+++ b/packages/blocks/src/api/raw-handling/test/utils.js
@@ -109,20 +109,20 @@ describe( 'removeInvalidHTML', () => {
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
 
-	it( 'should keep id attributes', () => {
+	it( 'should remove id attributes', () => {
 		const input = '<p id="foo">test</p>';
-		const output = '<p id="foo">test</p>';
+		const output = '<p>test</p>';
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
 
 	it( 'should remove multiple attributes', () => {
-		const input = '<p class="test" style="test">test</p>';
+		const input = '<p class="test" id="test">test</p>';
 		const output = '<p>test</p>';
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
 
 	it( 'should deep remove attributes', () => {
-		const input = '<p class="test">test <em style="test">test</em></p>';
+		const input = '<p class="test">test <em id="test">test</em></p>';
 		const output = '<p>test <em>test</em></p>';
 		expect( removeInvalidHTML( input, schema ) ).toBe( output );
 	} );
diff --git a/packages/blocks/src/api/raw-handling/utils.js b/packages/blocks/src/api/raw-handling/utils.js
index 158b8fd9064a91..c26be68df98a4f 100644
--- a/packages/blocks/src/api/raw-handling/utils.js
+++ b/packages/blocks/src/api/raw-handling/utils.js
@@ -7,6 +7,7 @@ import { omit, mergeWith, includes, noop } from 'lodash';
  * WordPress dependencies
  */
 import { unwrap, insertAfter, remove } from '@wordpress/dom';
+import { hasBlockSupport } from '..';
 
 /**
  * Browser dependencies
@@ -67,7 +68,18 @@ export function isPhrasingContent( node ) {
  * @return {Object} A complete block content schema.
  */
 export function getBlockContentSchema( transforms ) {
-	const schemas = transforms.map( ( { schema } ) => schema );
+	const schemas = transforms.map( ( { blockName, schema } ) => {
+		// If the block supports the "anchor" functionality, it needs to keep its ID attribute.
+		if ( hasBlockSupport( blockName, 'anchor' ) ) {
+			for ( const tag in schema ) {
+				if ( ! schema[ tag ].attributes ) {
+					schema[ tag ].attributes = [];
+				}
+				schema[ tag ].attributes.push( 'id' );
+			}
+		}
+		return schema;
+	} );
 
 	return mergeWith( {}, ...schemas, ( objValue, srcValue, key ) => {
 		if ( key === 'children' ) {
@@ -197,7 +209,7 @@ function cleanNodeList( nodeList, doc, schema, inline ) {
 				if ( node.hasAttributes() ) {
 					// Strip invalid attributes.
 					Array.from( node.attributes ).forEach( ( { name } ) => {
-						if ( name !== 'class' && name !== 'id' && ! includes( attributes, name ) ) {
+						if ( name !== 'class' && ! includes( attributes, name ) ) {
 							node.removeAttribute( name );
 						}
 					} );