Activate no-useless-escape rule of eslint

sao/eslint.config.mjs

@@ -22,7 +22,6 @@ export default [
         },
         rules: {
             "no-unused-vars": ["error", { "args": "none" }],
-            "no-useless-escape": "off",
             "no-with": "off",
         },
     }, {

sao/src/common.js

@@ -3023,7 +3023,7 @@
 
     Sao.common.guess_mimetype = function(filename) {
         for (var ext in Sao.common.mimetypes) {
-            var re = new RegExp('.*\.' + ext + '$', 'i');
+            var re = new RegExp('.*.' + ext + '$', 'i');
             if (re.test(filename)) {
                 return Sao.common.mimetypes[ext];
             }

sao/src/window.js

@@ -1324,7 +1324,7 @@
                 'id': 'input-quotechar',
                 'size': '1',
                 'maxlength': '1',
-                'value': '\"',
+                'value': '"',
             });
 
             jQuery('<div/>', {

sao/tests/sao.js

@@ -1667,7 +1667,7 @@
         [
         ['test', 'test'],
         ['foo bar', '"foo bar"'],
-        ['"foo"', '\\\"foo\\\"'],
+        ['"foo"', '\\"foo\\"'],
         ['foo\\bar', 'foo\\\\bar']
         ].forEach(function(test) {
             var value = test[0];