Trim leading whitespace from AJAX responses.

This fixes the warning "$(html) HTML strings must start with '<' character" by jQuery Migrate when adding nav menu items, post custom fields or comment replies.

fixes #23681.
Built from https://develop.svn.wordpress.org/trunk@25546


git-svn-id: http://core.svn.wordpress.org/trunk@25466 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/edit-comments.js

@@ -495,7 +495,6 @@ commentReply = {
 		t.revert();
 
 		r = r.responses[0];
-		c = r.data;
 		id = '#comment-' + r.id;
 
 		if ( 'edit-comment' == t.act )
@@ -513,8 +512,10 @@ commentReply = {
 			}
 		}
 
+		c = $.trim(r.data); // Trim leading whitespaces
 		$(c).hide()
 		$('#replyrow').after(c);
+
 		id = $(id);
 		t.addEvents(id);
 		bg = id.hasClass('unapproved') ? '#FFFFE0' : id.closest('.widefat, .postbox').css('backgroundColor');

wp-admin/js/nav-menu.js

@@ -902,12 +902,16 @@ var wpNavMenu;
 
 			$.post( ajaxurl, params, function(menuMarkup) {
 				var ins = $('#menu-instructions');
+
+				menuMarkup = $.trim( menuMarkup ); // Trim leading whitespaces
 				processMethod(menuMarkup, params);
+
 				// Make it stand out a bit more visually, by adding a fadeIn
 				$( 'li.pending' ).hide().fadeIn('slow');
 				$( '.drag-instructions' ).show();
 				if( ! ins.hasClass( 'menu-instructions-inactive' ) && ins.siblings().length )
 					ins.addClass( 'menu-instructions-inactive' );
+
 				callback();
 			});
 		},

wp-includes/js/wp-lists.js

@@ -208,7 +208,7 @@ wpList = {
 					s.delAfter( rres, _s );
 				}).dequeue();
 			}
-		}
+		};
 
 		$.ajax( s );
 		return false;
@@ -308,7 +308,7 @@ wpList = {
 	},
 
 	add: function( e, s ) {
-		e = $(e);
+		e = $( $.trim(e) ); // Trim leading whitespaces
 
 		var list = $(this), old = false, _s = { pos: 0, id: 0, oldId: null }, ba, ref, color;