Core: Drop support for Edge Legacy (i.e. non-Chromium Microsoft Edge)

Drop support for Edge Legacy: the non-Chromium, EdgeHTML-based Microsoft
Edge version. Also, restrict some workarounds that were applied
unconditionally in all browsers to run only in IE now. This slightly
increases the size but reduces the performance burden on modern browsers
that don't need the workarounds.

Also, clean up some comments & remove some obsolete workarounds.

Fixes gh-4568
Closes gh-4792

Author: mgol

src/ajax.js

@@ -543,7 +543,7 @@ jQuery.extend( {
 		if ( s.crossDomain == null ) {
 			urlAnchor = document.createElement( "a" );
 
-			// Support: IE <=8 - 11+, Edge 12 - 17 only
+			// Support: IE <=8 - 11+
 			// IE throws exception on accessing the href property if url is malformed,
 			// e.g. http://example.com:80x/
 			try {

src/attributes/prop.js

@@ -69,8 +69,10 @@ jQuery.extend( {
 
 				if (
 					rfocusable.test( elem.nodeName ) ||
-					rclickable.test( elem.nodeName ) &&
-					elem.href
+
+					// href-less anchor's `tabIndex` property value is `0` and
+					// the `tabindex` attribute value: `null`. We want `-1`.
+					rclickable.test( elem.nodeName ) && elem.href
 				) {
 					return 0;
 				}

src/core.js

@@ -273,18 +273,7 @@ jQuery.extend( {
 				ret += jQuery.text( node );
 			}
 		} else if ( nodeType === 1 || nodeType === 9 || nodeType === 11 ) {
-
-			// Use textContent for elements
-			// innerText usage removed for consistency of new lines (jQuery #11153)
-			if ( typeof elem.textContent === "string" ) {
-				return elem.textContent;
-			} else {
-
-				// Traverse its children
-				for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {
-					ret += jQuery.text( elem );
-				}
-			}
+			return elem.textContent;
 		} else if ( nodeType === 3 || nodeType === 4 ) {
 			return elem.nodeValue;
 		}

src/core/DOMEval.js

@@ -10,26 +10,14 @@ var preservedScriptAttributes = {
 function DOMEval( code, node, doc ) {
 	doc = doc || document;
 
-	var i, val,
+	var i,
 		script = doc.createElement( "script" );
 
 	script.text = code;
 	if ( node ) {
 		for ( i in preservedScriptAttributes ) {
-
-			// Support: Firefox <=64 - 66+, Edge <=18+
-			// Some browsers don't support the "nonce" property on scripts.
-			// On the other hand, just using `getAttribute` is not enough as
-			// the `nonce` attribute is reset to an empty string whenever it
-			// becomes browsing-context connected.
-			// See https://github.com/whatwg/html/issues/2369
-			// See https://html.spec.whatwg.org/#nonce-attributes
-			// The `node.getAttribute` check was added for the sake of
-			// `jQuery.globalEval` so that it can fake a nonce-containing node
-			// via an object.
-			val = node[ i ] || node.getAttribute && node.getAttribute( i );
-			if ( val ) {
-				script.setAttribute( i, val );
+			if ( node[ i ] ) {
+				script[ i ] = node[ i ];
 			}
 		}
 	}

src/core/isAttached.js

@@ -4,16 +4,17 @@ import documentElement from "../var/documentElement.js";
 import "../selector/contains.js"; // jQuery.contains
 
 var isAttached = function( elem ) {
-		return jQuery.contains( elem.ownerDocument, elem );
+		return jQuery.contains( elem.ownerDocument, elem ) ||
+			elem.getRootNode( composed ) === elem.ownerDocument;
 	},
 	composed = { composed: true };
 
-// Support: IE 9 - 11+, Edge 12 - 18+
-// Check attachment across shadow DOM boundaries when possible (gh-3504)
-if ( documentElement.getRootNode ) {
+// Support: IE 9 - 11+
+// Check attachment across shadow DOM boundaries when possible (gh-3504).
+// Provide a fallback for browsers without Shadow DOM v1 support.
+if ( !documentElement.getRootNode ) {
 	isAttached = function( elem ) {
-		return jQuery.contains( elem.ownerDocument, elem ) ||
-			elem.getRootNode( composed ) === elem.ownerDocument;
+		return jQuery.contains( elem.ownerDocument, elem );
 	};
 }
 

src/css.js

@@ -11,7 +11,6 @@ import getStyles from "./css/var/getStyles.js";
 import swap from "./css/var/swap.js";
 import curCSS from "./css/curCSS.js";
 import adjustCSS from "./css/adjustCSS.js";
-import support from "./css/support.js";
 import finalPropName from "./css/finalPropName.js";
 
 import "./core/init.js";
@@ -135,15 +134,19 @@ function getWidthOrHeight( elem, dimension, extra ) {
 	}
 
 
-	// Support: IE 9 - 11+
-	// Use offsetWidth/offsetHeight for when box sizing is unreliable.
-	// In those cases, the computed value can be trusted to be border-box.
-	if ( ( isIE && isBorderBox ||
+	if ( ( isIE &&
+		(
 
-		// Support: IE 10 - 11+, Edge 15 - 18+
-		// IE/Edge misreport `getComputedStyle` of table rows with width/height
-		// set in CSS while `offset*` properties report correct values.
-		!support.reliableTrDimensions() && nodeName( elem, "tr" ) ||
+			// Support: IE 9 - 11+
+			// Use offsetWidth/offsetHeight for when box sizing is unreliable.
+			// In those cases, the computed value can be trusted to be border-box.
+			isBorderBox ||
+
+			// Support: IE 10 - 11+
+			// IE misreports `getComputedStyle` of table rows with width/height
+			// set in CSS while `offset*` properties report correct values.
+			nodeName( elem, "tr" )
+		) ||
 
 		// Fall back to offsetWidth/offsetHeight when value is "auto"
 		// This happens for inline elements with no explicit setting (gh-3571)

src/css/cssCamelCase.js

@@ -5,7 +5,7 @@ var rmsPrefix = /^-ms-/;
 
 // Convert dashed to camelCase, handle vendor prefixes.
 // Used by the css & effects modules.
-// Support: IE <=9 - 11+, Edge 12 - 18+
+// Support: IE <=9 - 11+
 // Microsoft forgot to hump their vendor prefix (#9572)
 function cssCamelCase( string ) {
 	return camelCase( string.replace( rmsPrefix, "ms-" ) );

src/css/support.js

@@ -143,10 +143,9 @@ function defaultPrefilter( elem, props, opts ) {
 	// Restrict "overflow" and "display" styles during box animations
 	if ( isBox && elem.nodeType === 1 ) {
 
-		// Support: IE <=9 - 11+, Edge 12 - 18+
+		// Support: IE <=9 - 11+
 		// Record all 3 overflow attributes because IE does not infer the shorthand
-		// from identically-valued overflowX and overflowY and Edge just mirrors
-		// the overflowX value there.
+		// from identically-valued overflowX and overflowY.
 		opts.overflow = [ style.overflow, style.overflowX, style.overflowY ];
 
 		// Identify a display type, preferring old show/hide data over the CSS cascade

src/effects.js

@@ -23,9 +23,8 @@ import "./event.js";
 
 var
 
-	// Support: IE <=10 - 11+, Edge 12 - 13 only
-	// In IE/Edge using regex groups here causes severe slowdowns.
-	// See https://connect.microsoft.com/IE/feedback/details/1736512/
+	// Support: IE <=10 - 11+
+	// In IE using regex groups here causes severe slowdowns.
 	rnoInnerhtml = /<script|<style|<link/i,
 
 	rcleanScript = /^\s*<!(?:\[CDATA\[|--)|(?:\]\]|--)>\s*$/g;
@@ -157,7 +156,7 @@ function domManip( collection, args, callback, ignored ) {
 							// Optional AJAX dependency, but won't run scripts if not present
 							if ( jQuery._evalUrl && !node.noModule ) {
 								jQuery._evalUrl( node.src, {
-									nonce: node.nonce || node.getAttribute( "nonce" ),
+									nonce: node.nonce,
 									crossOrigin: node.crossOrigin
 								}, doc );
 							}