In get_avatar(), revert the <img> tag attributes to using single quotes, instead of double quotes. This behaviour was changed in [31107], but caused problems for code that attempted to parse the <img> tag.

See #21195



git-svn-id: https://develop.svn.wordpress.org/trunk@31152 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/pluggable.php

@@ -2181,7 +2181,7 @@ function get_avatar( $id_or_email, $size = 96, $default = '', $alt = '', $args =
 	}
 
 	$avatar = sprintf(
-		'<img alt="%s" src="%s" class="%s" height="%d" width="%d" />',
+		"<img alt='%s' src='%s' class='%s' height='%d' width='%d' />",
 		esc_attr( $args['alt'] ),
 		esc_url( $url ),
 		esc_attr( join( ' ', $class ) ),