General: Return "O B" when passing 0 to size_format().

Props swissspidy.
Fixes #36635.

git-svn-id: https://develop.svn.wordpress.org/trunk@37962 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/functions.php

@@ -263,6 +263,10 @@ function size_format( $bytes, $decimals = 0 ) {
 		'B'  => 1,
 	);
 
+	if ( 0 === $bytes ) {
+		return number_format_i18n( 0, $decimals ) . ' B';
+	}
+
 	foreach ( $quant as $unit => $mag ) {
 		if ( doubleval( $bytes ) >= $mag ) {
 			return number_format_i18n( $bytes / $mag, $decimals ) . ' ' . $unit;