Set only Last-Modified with header(), which merges into existing headers

pi-20 · pi-20 · commit 200e517f9a12 · 2026-04-09T12:54:59.000+05:30
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -585,10 +585,9 @@ protected function add_last_modified_header( $response, $post ) {
 			return;
 		}
 
-		$response->set_headers(
-			array(
-				'Last-Modified' => gmdate( 'D, d M Y H:i:s', $modified->getTimestamp() ) . ' GMT',
-			)
+		$response->header(
+			'Last-Modified',
+			gmdate( 'D, d M Y H:i:s', $modified->getTimestamp() ) . ' GMT'
 		);
 	}
 

Original file line number	Diff line number	Diff line change
`@@ -585,10 +585,9 @@ protected function add_last_modified_header( $response, $post ) {`
`585`	`585`	`return;`
`586`	`586`	`}`
`587`	`587`
`588`		`- $response->set_headers(`
`589`		`- array(`
`590`		`- 'Last-Modified' => gmdate( 'D, d M Y H:i:s', $modified->getTimestamp() ) . ' GMT',`
`591`		`- )`
	`588`	`+ $response->header(`
	`589`	`+ 'Last-Modified',`
	`590`	`+ gmdate( 'D, d M Y H:i:s', $modified->getTimestamp() ) . ' GMT'`
`592`	`591`	`);`
`593`	`592`	`}`
`594`	`593`