Custom select: Escape weird characters in popup/dialog ID when they b…

…ecome hrefs. Fixes #5893.

js/widgets/forms/select.custom.js

@@ -98,7 +98,10 @@ define( [
 			placeholder: "",
 
 			build: function() {
-				var self = this;
+				var self = this,
+					escapeId = function( id ) {
+						return id.replace( /([!"#$%&'()*+,./:;<=>?@[\]^`{|}~])/g, "\\$1" );
+					}
 
 				// Create list from select, update state
 				self.refresh();
@@ -128,9 +131,9 @@ define( [
 
 						self._decideFormat();
 						if ( self.menuType === "overlay" ) {
-							self.button.attr( "href", "#" + self.popupID ).attr( "data-" + ( $.mobile.ns || "" ) + "rel", "popup" );
+							self.button.attr( "href", "#" + escapeId( self.popupID ) ).attr( "data-" + ( $.mobile.ns || "" ) + "rel", "popup" );
 						} else {
-							self.button.attr( "href", "#" + self.dialogID ).attr( "data-" + ( $.mobile.ns || "" ) + "rel", "dialog" );
+							self.button.attr( "href", "#" + escapeId( self.dialogID ) ).attr( "data-" + ( $.mobile.ns || "" ) + "rel", "dialog" );
 						}
 						self.isOpen = true;
 						// Do not prevent default, so the navigation may have a chance to actually open the chosen format