diff -r 34716fd837a4 -r be944660c56a wp/wp-includes/class.wp-scripts.php
--- a/wp/wp-includes/class.wp-scripts.php	Tue Dec 15 15:52:01 2020 +0100
+++ b/wp/wp-includes/class.wp-scripts.php	Wed Sep 21 18:19:35 2022 +0200
@@ -415,7 +415,7 @@
 	 *
 	 * @param string $handle   Name of the script to add the inline script to.
 	 *                         Must be lowercase.
-	 * @param string $data     String containing the javascript to be added.
+	 * @param string $data     String containing the JavaScript to be added.
 	 * @param string $position Optional. Whether to add the inline script
 	 *                         before the handle or after. Default 'after'.
 	 * @return bool True on success, false on failure.
@@ -484,12 +484,29 @@
 			unset( $l10n['l10n_print_after'] );
 		}
 
-		foreach ( (array) $l10n as $key => $value ) {
-			if ( ! is_scalar( $value ) ) {
-				continue;
+		if ( ! is_array( $l10n ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				sprintf(
+					/* translators: 1: $l10n, 2: wp_add_inline_script() */
+					__( 'The %1$s parameter must be an array. To pass arbitrary data to scripts, use the %2$s function instead.' ),
+					'<code>$l10n</code>',
+					'<code>wp_add_inline_script()</code>'
+				),
+				'5.7.0'
+			);
+		}
+
+		if ( is_string( $l10n ) ) {
+			$l10n = html_entity_decode( $l10n, ENT_QUOTES, 'UTF-8' );
+		} else {
+			foreach ( (array) $l10n as $key => $value ) {
+				if ( ! is_scalar( $value ) ) {
+					continue;
+				}
+
+				$l10n[ $key ] = html_entity_decode( (string) $value, ENT_QUOTES, 'UTF-8' );
 			}
-
-			$l10n[ $key ] = html_entity_decode( (string) $value, ENT_QUOTES, 'UTF-8' );
 		}
 
 		$script = "var $object_name = " . wp_json_encode( $l10n ) . ';';