diff --git a/lib/ace/mode/javascript/jshint.js b/lib/ace/mode/javascript/jshint.js
index 6c6054618e8..adc51597e48 100644
--- a/lib/ace/mode/javascript/jshint.js
+++ b/lib/ace/mode/javascript/jshint.js
@@ -3265,68 +3265,7 @@ module.exports = slice;
   // and correctly escapes quotes within interpolated code.
   // NB: `oldSettings` only exists for backwards compatibility.
   function template(text, settings, oldSettings) {
-    if (!settings && oldSettings) settings = oldSettings;
-    settings = defaults({}, settings, _$1.templateSettings);
-
-    // Combine delimiters into one regular expression via alternation.
-    var matcher = RegExp([
-      (settings.escape || noMatch).source,
-      (settings.interpolate || noMatch).source,
-      (settings.evaluate || noMatch).source
-    ].join('|') + '|$', 'g');
-
-    // Compile the template source, escaping string literals appropriately.
-    var index = 0;
-    var source = "__p+='";
-    text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
-      source += text.slice(index, offset).replace(escapeRegExp, escapeChar);
-      index = offset + match.length;
-
-      if (escape) {
-        source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
-      } else if (interpolate) {
-        source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
-      } else if (evaluate) {
-        source += "';\n" + evaluate + "\n__p+='";
-      }
-
-      // Adobe VMs need the match returned to produce the correct offset.
-      return match;
-    });
-    source += "';\n";
-
-    var argument = settings.variable;
-    if (argument) {
-      // Insure against third-party code injection. (CVE-2021-23358)
-      if (!bareIdentifier.test(argument)) throw new Error(
-        'variable is not a bare identifier: ' + argument
-      );
-    } else {
-      // If a variable is not specified, place data values in local scope.
-      source = 'with(obj||{}){\n' + source + '}\n';
-      argument = 'obj';
-    }
-
-    source = "var __t,__p='',__j=Array.prototype.join," +
-      "print=function(){__p+=__j.call(arguments,'');};\n" +
-      source + 'return __p;\n';
-
-    var render;
-    try {
-      render = new Function(argument, '_', source);
-    } catch (e) {
-      e.source = source;
-      throw e;
-    }
-
-    var template = function(data) {
-      return render.call(this, data, _$1);
-    };
-
-    // Provide the compiled source as a convenience for precompilation.
-    template.source = 'function(' + argument + '){\n' + source + '}';
-
-    return template;
+    console.error("should not happen");
   }
 
   // Traverses the children of `obj` along `path`. If a child is a function, it
diff --git a/lib/ace/mode/yaml/yaml-lint.js b/lib/ace/mode/yaml/yaml-lint.js
index 6c7afaad6f3..2969341435e 100644
--- a/lib/ace/mode/yaml/yaml-lint.js
+++ b/lib/ace/mode/yaml/yaml-lint.js
@@ -3500,37 +3500,7 @@ function resolveJavascriptFunction(data) {
 }
 
 function constructJavascriptFunction(data) {
-  /*jslint evil:true*/
-
-  var source = '(' + data + ')',
-      ast    = esprima.parse(source, { range: true }),
-      params = [],
-      body;
-
-  if (ast.type                    !== 'Program'             ||
-      ast.body.length             !== 1                     ||
-      ast.body[0].type            !== 'ExpressionStatement' ||
-      (ast.body[0].expression.type !== 'ArrowFunctionExpression' &&
-        ast.body[0].expression.type !== 'FunctionExpression')) {
-    throw new Error('Failed to resolve function');
-  }
-
-  ast.body[0].expression.params.forEach(function (param) {
-    params.push(param.name);
-  });
-
-  body = ast.body[0].expression.body.range;
-
-  // Esprima's ranges include the first '{' and the last '}' characters on
-  // function expressions. So cut them out.
-  if (ast.body[0].expression.body.type === 'BlockStatement') {
-    /*eslint-disable no-new-func*/
-    return new Function(params, source.slice(body[0] + 1, body[1] - 1));
-  }
-  // ES6 arrow functions can omit the BlockStatement. In that case, just return
-  // the body.
-  /*eslint-disable no-new-func*/
-  return new Function(params, 'return ' + source.slice(body[0], body[1]));
+  return function() {}
 }
 
 function representJavascriptFunction(object /*, style*/) {
diff --git a/src/ext/modelist.js b/src/ext/modelist.js
index 07092bb1405..89b03632b2c 100644
--- a/src/ext/modelist.js
+++ b/src/ext/modelist.js
@@ -40,7 +40,7 @@ class Mode {
             }) + "$";
         }
         else {
-            re = "^.*\\.(" + extensions + ")$";
+            re = "\\.(" + extensions + ")$";
         }
 
         this.extRe = new RegExp(re, "gi");
diff --git a/src/mode/_test/highlight_rules_test.js b/src/mode/_test/highlight_rules_test.js
index a2f84d80326..e0db6898877 100644
--- a/src/mode/_test/highlight_rules_test.js
+++ b/src/mode/_test/highlight_rules_test.js
@@ -329,6 +329,7 @@ function checkBacktracking(tokenizer) {
             var regex = rule.regex;
             if (regex && typeof regex != "string") regex = regex.source;
             if (!regex) return;
+            regex = "(" + regex + ")|";
             var result = require("recheck").checkSync(regex, "gmi", {
                 checker: "automaton",
                 timeout: 100000