From da3dd85b63c4e3a6a768132c2a83a1a6eec24840 Mon Sep 17 00:00:00 2001
From: Sean Robinson <sean.robinson@scottsdalecc.edu>
Date: Fri, 26 Apr 2019 07:25:08 -0700
Subject: [PATCH] Ajax: Do not execute scripts for unsuccessful HTTP responses

The script transport used to evaluate fetched script sources which is
undesirable for unsuccessful HTTP responses. This is different to other data
types where such a convention was fine (e.g. in case of JSON).

(cherry picked from 50871a5a85cc802421b40cc67e2830601968affe)

Fixes gh-4250
Fixes gh-4655
Closes gh-4379
---
 src/ajax.js                   |   5 ++
 test/data/mock.php            |  13 ++++
 test/middleware-mockserver.js |  12 ++++
 test/unit/ajax.js             | 115 ++++++++++++++++++++++++++++++++++
 4 files changed, 145 insertions(+)

diff --git a/src/ajax.js b/src/ajax.js
index 7e8f552aac..d1bebd540e 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -744,6 +744,11 @@ jQuery.extend( {
 				response = ajaxHandleResponses( s, jqXHR, responses );
 			}
 
+			// Use a noop converter for missing script
+			if ( !isSuccess && jQuery.inArray( "script", s.dataTypes ) > -1 ) {
+				s.converters[ "text script" ] = function() {};
+			}
+
 			// Convert no matter what (that way responseXXX fields are always set)
 			response = ajaxConvert( s, response, jqXHR, isSuccess );
 
diff --git a/test/data/mock.php b/test/data/mock.php
index ba19304153..5b56d02c7e 100644
--- a/test/data/mock.php
+++ b/test/data/mock.php
@@ -216,6 +216,19 @@ QUnit.assert.ok( true, "mock executed");';
 		unlink( $this->cspFile );
 	}
 
+	protected function errorWithScript( $req ) {
+		header( 'HTTP/1.0 404 Not Found' );
+		if ( isset( $req->query['withScriptContentType'] ) ) {
+			header( 'Content-Type: application/javascript' );
+		}
+		if ( isset( $req->query['callback'] ) ) {
+			$callback = $req->query['callback'];
+			echo $callback . '( {"status": 404, "msg": "Not Found"} )';
+		} else {
+			echo 'QUnit.assert.ok( false, "Mock return erroneously executed" );';
+		}
+	}
+
 	public function __construct() {
 		$this->cspFile = __DIR__ . '/support/csp.log';
 	}
diff --git a/test/middleware-mockserver.js b/test/middleware-mockserver.js
index 20a6607140..bddfafc94f 100644
--- a/test/middleware-mockserver.js
+++ b/test/middleware-mockserver.js
@@ -226,6 +226,18 @@ var mocks = {
 		cspLog = "";
 		resp.writeHead( 200 );
 		resp.end();
+	},
+	errorWithScript: function( req, resp ) {
+		if ( req.query.withScriptContentType ) {
+			resp.writeHead( 404, { "Content-Type": "application/javascript" } );
+		} else {
+			resp.writeHead( 404 );
+		}
+		if ( req.query.callback ) {
+			resp.end( req.query.callback + "( {\"status\": 404, \"msg\": \"Not Found\"} )" );
+		} else {
+			resp.end( "QUnit.assert.ok( false, \"Mock return erroneously executed\" );" );
+		}
 	}
 };
 var handlers = {
diff --git a/test/unit/ajax.js b/test/unit/ajax.js
index d9b984799c..8b3850605e 100644
--- a/test/unit/ajax.js
+++ b/test/unit/ajax.js
@@ -837,6 +837,121 @@ QUnit.module( "ajax", {
 		};
 	} );
 
+	ajaxTest( "jQuery.ajax() - do not execute scripts from unsuccessful responses (gh-4250)", 11, function( assert ) {
+		var globalEval = jQuery.globalEval;
+
+		var failConverters = {
+			"text script": function() {
+				assert.ok( false, "No converter for unsuccessful response" );
+			}
+		};
+
+		function request( title, options ) {
+			var testMsg = title + ": expected file missing status";
+			return jQuery.extend( {
+				beforeSend: function() {
+					jQuery.globalEval = function() {
+						assert.ok( false, "Should not eval" );
+					};
+				},
+				complete: function() {
+					jQuery.globalEval = globalEval;
+				},
+				// error is the significant assertion
+				error: function( xhr ) {
+					assert.strictEqual( xhr.status, 404, testMsg );
+				},
+				success: function() {
+					assert.ok( false, "Unanticipated success" );
+				}
+			}, options );
+		}
+
+		return [
+			request(
+				"HTML reply",
+				{
+					url: url( "404.txt" )
+				}
+			),
+			request(
+				"HTML reply with dataType",
+				{
+					dataType: "script",
+					url: url( "404.txt" )
+				}
+			),
+			request(
+				"script reply",
+				{
+					url: url( "mock.php?action=errorWithScript&withScriptContentType" )
+				}
+			),
+			request(
+				"non-script reply",
+				{
+					url: url( "mock.php?action=errorWithScript" )
+				}
+			),
+			request(
+				"script reply with dataType",
+				{
+					dataType: "script",
+					url: url( "mock.php?action=errorWithScript&withScriptContentType" )
+				}
+			),
+			request(
+				"non-script reply with dataType",
+				{
+					dataType: "script",
+					url: url( "mock.php?action=errorWithScript" )
+				}
+			),
+			request(
+				"script reply with converter",
+				{
+					converters: failConverters,
+					url: url( "mock.php?action=errorWithScript&withScriptContentType" )
+				}
+			),
+			request(
+				"non-script reply with converter",
+				{
+					converters: failConverters,
+					url: url( "mock.php?action=errorWithScript" )
+				}
+			),
+			request(
+				"script reply with converter and dataType",
+				{
+					converters: failConverters,
+					dataType: "script",
+					url: url( "mock.php?action=errorWithScript&withScriptContentType" )
+				}
+			),
+			request(
+				"non-script reply with converter and dataType",
+				{
+					converters: failConverters,
+					dataType: "script",
+					url: url( "mock.php?action=errorWithScript" )
+				}
+			),
+			request(
+				"JSONP reply with dataType",
+				{
+					dataType: "jsonp",
+					url: url( "mock.php?action=errorWithScript" ),
+					beforeSend: function() {
+						jQuery.globalEval = function( response ) {
+							assert.ok( /"status": 404, "msg": "Not Found"/.test( response ), "Error object returned" );
+						};
+					}
+				}
+			)
+		];
+	} );
+
 	ajaxTest( "jQuery.ajax() - synchronous request", 1, function( assert ) {
 		return {
 			url: url( "json_obj.js" ),