diff --git a/src/wp-includes/js/wplink.js b/src/wp-includes/js/wplink.js
index 339ce02ee6..0334be1a78 100644
--- a/src/wp-includes/js/wplink.js
+++ b/src/wp-includes/js/wplink.js
@@ -270,14 +270,14 @@ var wpLink;
 		setDefaultValues: function() {
 			var selection = editor && editor.selection.getContent(),
 				emailRegexp = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i,
-				urlRegexp = /^(https?|ftp):\/\/[A-Z0-9.-]+\.[A-Z]{2,4}$/i;
+				urlRegexp = /^(https?|ftp):\/\/[A-Z0-9.-]+\.[A-Z]{2,4}[^ "]*$/i;
 
 			if ( selection && emailRegexp.test( selection ) ) {
 				// Selection is email address
 				inputs.url.val( 'mailto:' + selection );
 			} else if ( selection && urlRegexp.test( selection ) ) {
 				// Selection is URL
-				inputs.url.val( selection );
+				inputs.url.val( selection.replace( /&|&#0?38;/gi, '&' ) );
 			} else {
 				// Set URL to default.
 				inputs.url.val( 'http://' );