update

web/jquery/src/css/var/isHiddenWithinTree.js

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+define( [
+	"../../core",
+	"../../core/isAttached"
+
+	// css is assumed
+], function( jQuery, isAttached ) {
+	"use strict";
+
+	// isHiddenWithinTree reports if an element has a non-"none" display style (inline and/or
+	// through the CSS cascade), which is useful in deciding whether or not to make it visible.
+	// It differs from the :hidden selector (jQuery.expr.pseudos.hidden) in two important ways:
+	// * A hidden ancestor does not force an element to be classified as hidden.
+	// * Being disconnected from the document does not force an element to be classified as hidden.
+	// These differences improve the behavior of .toggle() et al. when applied to elements that are
+	// detached or contained within hidden ancestors (gh-2404, gh-2863).
+	return function( elem, el ) {
+
+		// isHiddenWithinTree might be called from jQuery#filter function;
+		// in that case, element will be second argument
+		elem = el || elem;
+
+		// Inline style trumps all
+		return elem.style.display === "none" ||
+			elem.style.display === "" &&
+
+			// Otherwise, check computed style
+			// Support: Firefox <=43 - 45
+			// Disconnected elements can have computed display: none, so first confirm that elem is
+			// in the document.
+			isAttached( elem ) &&
+
+			jQuery.css( elem, "display" ) === "none";
+	};
+} );