Editor: Fix new posts being published with the auto-draft slug

packages/editor/CHANGELOG.md

@@ -9,6 +9,7 @@
 ### Bug Fixes
 
 -   Error boundary: Explicitly announce the error title and description, excluding action labels ([#82737](https://github.com/WordPress/gutenberg/pull/82737)).
+-   `PostURL`: Leaving the slug field without typing no longer saves the displayed fallback as the slug, so a new post no longer publishes with the `auto-draft` slug ([#83518](https://github.com/WordPress/gutenberg/pull/83518)).
 
 ## 15.1.0 (2026-09-23)
 

packages/editor/src/components/post-url/index.jsx

@@ -34,6 +34,7 @@ export default function PostURL( { onClose } ) {
 	const {
 		isEditable,
 		postSlug,
+		hasSlug,
 		postLink,
 		permalinkPrefix,
 		permalinkSuffix,
@@ -51,6 +52,7 @@ export default function PostURL( { onClose } ) {
 			postSlug: safeDecodeURIComponent(
 				select( editorStore ).getEditedPostSlug()
 			),
+			hasSlug: !! select( editorStore ).getEditedPostAttribute( 'slug' ),
 			viewPostLabel: postType?.labels?.view_item,
 			postLink: post.link,
 			permalinkPrefix: permalinkParts?.prefix,
@@ -141,11 +143,16 @@ export default function PostURL( { onClose } ) {
 									}
 								} }
 								onBlur={ ( event ) => {
-									editPost( {
-										slug: cleanForSlug(
-											event.target.value
-										),
-									} );
+									// Without a slug the field shows a fallback, which for
+									// a new post is the `auto-draft` placeholder. Writing
+									// it would pin that value as the post slug.
+									if ( hasSlug ) {
+										editPost( {
+											slug: cleanForSlug(
+												event.target.value
+											),
+										} );
+									}
 									if ( forceEmptyField ) {
 										setForceEmptyField( false );
 									}

test/e2e/specs/editor/various/sidebar-permalink.spec.js

@@ -10,6 +10,7 @@ test.describe( 'Sidebar Permalink', () => {
 	} );
 
 	test.afterAll( async ( { requestUtils } ) => {
+		await requestUtils.deleteAllPosts();
 		await requestUtils.deactivatePlugin(
 			'gutenberg-test-custom-post-types'
 		);
@@ -75,4 +76,28 @@ test.describe( 'Sidebar Permalink', () => {
 			page.getByRole( 'button', { name: 'Change link' } )
 		).toBeVisible();
 	} );
+
+	test( 'should not save the placeholder slug of a new post when the slug field loses focus', async ( {
+		admin,
+		editor,
+		page,
+		requestUtils,
+	} ) => {
+		await admin.createNewPost();
+		await editor.openDocumentSettingsSidebar();
+		await editor.canvas
+			.getByRole( 'textbox', { name: 'Add title' } )
+			.fill( 'Hello Slug' );
+
+		await page.getByRole( 'button', { name: /^Change link/ } ).click();
+		await page.getByRole( 'textbox', { name: 'Slug' } ).click();
+		await page.keyboard.press( 'Tab' );
+		await page.keyboard.press( 'Escape' );
+
+		const postId = await editor.publishPost();
+		const post = await requestUtils.rest( {
+			path: `/wp/v2/posts/${ postId }`,
+		} );
+		expect( post.slug ).toBe( 'hello-slug' );
+	} );
 } );