chore: check namespace inside set attributes (#15443)

* set_attributes for <svelte:element>

* changeset

* Update .changeset/wise-hats-wonder.md

Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

* add changeset

* remove `chore` changeset — no need for non-user-facing changes to appear in changelog

* Update packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/element.js

* determine element traits inside set_attributes

* unused

* stash lookup

---------

Co-authored-by: adiguba <frederic.martini@gmail.com>
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>

.changeset/quiet-baboons-listen.md

@@ -0,0 +1,5 @@
+---
+"svelte": patch
+---
+
+fix: respect `svelte-ignore hydration_attribute_changed` on elements with spread attributes

packages/svelte/src/compiler/phases/3-transform/client/visitors/RegularElement.js

@@ -221,16 +221,7 @@ export function RegularElement(node, context) {
 	if (has_spread) {
 		const attributes_id = b.id(context.state.scope.generate('attributes'));
 
-		build_set_attributes(
-			attributes,
-			class_directives,
-			context,
-			node,
-			node_id,
-			attributes_id,
-			(node.metadata.svg || node.metadata.mathml || is_custom_element_node(node)) && b.true,
-			is_custom_element_node(node) && b.true
-		);
+		build_set_attributes(attributes, class_directives, context, node, node_id, attributes_id);
 
 		// If value binding exists, that one takes care of calling $.init_select
 		if (node.name === 'select' && !bindings.has('value')) {

packages/svelte/src/compiler/phases/3-transform/client/visitors/SvelteElement.js

@@ -114,9 +114,7 @@ export function SvelteElement(node, context) {
 			inner_context,
 			node,
 			element_id,
-			attributes_id,
-			b.binary('===', b.member(element_id, 'namespaceURI'), b.id('$.NAMESPACE_SVG')),
-			b.call(b.member(b.member(element_id, 'nodeName'), 'includes'), b.literal('-'))
+			attributes_id
 		);
 	}
 

packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/element.js

@@ -17,8 +17,6 @@ import { build_template_chunk, get_expression_id } from './utils.js';
  * @param {AST.RegularElement | AST.SvelteElement} element
  * @param {Identifier} element_id
  * @param {Identifier} attributes_id
- * @param {false | Expression} preserve_attribute_case
- * @param {false | Expression} is_custom_element
  */
 export function build_set_attributes(
 	attributes,
@@ -26,9 +24,7 @@ export function build_set_attributes(
 	context,
 	element,
 	element_id,
-	attributes_id,
-	preserve_attribute_case,
-	is_custom_element
+	attributes_id
 ) {
 	let is_dynamic = false;
 
@@ -91,8 +87,6 @@ export function build_set_attributes(
 		element.metadata.scoped &&
 			context.state.analysis.css.hash !== '' &&
 			b.literal(context.state.analysis.css.hash),
-		preserve_attribute_case,
-		is_custom_element,
 		is_ignored(element, 'hydration_attribute_changed') && b.true
 	);
 

packages/svelte/src/constants.js

@@ -33,6 +33,7 @@ export const UNINITIALIZED = Symbol();
 export const FILENAME = Symbol('filename');
 export const HMR = Symbol('hmr');
 
+export const NAMESPACE_HTML = 'http://www.w3.org/1999/xhtml';
 export const NAMESPACE_SVG = 'http://www.w3.org/2000/svg';
 export const NAMESPACE_MATHML = 'http://www.w3.org/1998/Math/MathML';
 

packages/svelte/src/internal/client/dom/elements/attributes.js

@@ -15,10 +15,14 @@ import {
 } from '../../runtime.js';
 import { clsx } from '../../../shared/attributes.js';
 import { set_class } from './class.js';
+import { NAMESPACE_HTML } from '../../../../constants.js';
 
 export const CLASS = Symbol('class');
 export const STYLE = Symbol('style');
 
+const IS_CUSTOM_ELEMENT = Symbol('is custom element');
+const IS_HTML = Symbol('is html');
+
 /**
  * The value/checked attribute in the template actually corresponds to the defaultValue property, so we need
  * to remove it upon hydration to avoid a bug when someone resets the form value.
@@ -63,8 +67,7 @@ export function remove_input_defaults(input) {
  * @param {any} value
  */
 export function set_value(element, value) {
-	// @ts-expect-error
-	var attributes = (element.__attributes ??= {});
+	var attributes = get_attributes(element);
 
 	if (
 		attributes.value ===
@@ -87,8 +90,7 @@ export function set_value(element, value) {
  * @param {boolean} checked
  */
 export function set_checked(element, checked) {
-	// @ts-expect-error
-	var attributes = (element.__attributes ??= {});
+	var attributes = get_attributes(element);
 
 	if (
 		attributes.checked ===
@@ -151,8 +153,7 @@ export function set_default_value(element, value) {
  * @param {boolean} [skip_warning]
  */
 export function set_attribute(element, attribute, value, skip_warning) {
-	// @ts-expect-error
-	var attributes = (element.__attributes ??= {});
+	var attributes = get_attributes(element);
 
 	if (hydrating) {
 		attributes[attribute] = element.getAttribute(attribute);
@@ -261,20 +262,15 @@ export function set_custom_element_data(node, prop, value) {
  * @param {Record<string | symbol, any> | undefined} prev
  * @param {Record<string | symbol, any>} next New attributes - this function mutates this object
  * @param {string} [css_hash]
- * @param {boolean} [preserve_attribute_case]
- * @param {boolean} [is_custom_element]
  * @param {boolean} [skip_warning]
  * @returns {Record<string, any>}
  */
-export function set_attributes(
-	element,
-	prev,
-	next,
-	css_hash,
-	preserve_attribute_case = false,
-	is_custom_element = false,
-	skip_warning = false
-) {
+export function set_attributes(element, prev, next, css_hash, skip_warning = false) {
+	var attributes = get_attributes(element);
+
+	var is_custom_element = attributes[IS_CUSTOM_ELEMENT];
+	var preserve_attribute_case = !attributes[IS_HTML];
+
 	// If we're hydrating but the custom element is from Svelte, and it already scaffolded,
 	// then it might run block logic in hydration mode, which we have to prevent.
 	let is_hydrating_custom_element = hydrating && is_custom_element;
@@ -299,9 +295,6 @@ export function set_attributes(
 
 	var setters = get_setters(element);
 
-	// @ts-expect-error
-	var attributes = /** @type {Record<string, unknown>} **/ (element.__attributes ??= {});
-
 	// since key is captured we use const
 	for (const key in next) {
 		// let instead of var because referenced in a closure
@@ -432,7 +425,7 @@ export function set_attributes(
 				// @ts-ignore
 				element[name] = value;
 			} else if (typeof value !== 'function') {
-				set_attribute(element, name, value);
+				set_attribute(element, name, value, skip_warning);
 			}
 		}
 		if (key === 'style' && '__styles' in element) {
@@ -448,6 +441,20 @@ export function set_attributes(
 	return current;
 }
 
+/**
+ *
+ * @param {Element} element
+ */
+function get_attributes(element) {
+	return /** @type {Record<string | symbol, unknown>} **/ (
+		// @ts-expect-error
+		element.__attributes ??= {
+			[IS_CUSTOM_ELEMENT]: element.nodeName.includes('-'),
+			[IS_HTML]: element.namespaceURI === NAMESPACE_HTML
+		}
+	);
+}
+
 /** @type {Map<string, string[]>} */
 var setters_cache = new Map();