Description:
------------
We output some HTML markup inside a json_encoded string, with double quotes replaced by `\u0022` (with the `JSON_HEX_QUOT` flag)

the HTML markup contains a `<a href="javascript:...>` link

which becomes `<a href=\u0022javascript:...>` when json_encoded

we also use `output_add_rewrite_var`, and had no problem when using PHP 5.6 or PHP 7.0
(i.e .the parameter was not added, since this a JavaScript call, not a URL),

but it seems since PHP 7.1.0 the URL parameter is added just before the first argument of the JavaScript function in the `href` attribute, resulting in a JavaScript error when it is clicked.



Test script:
---------------
<?php
// tried this on https://3v4l.org/fmRvE

output_add_rewrite_var('param_name', 'param_value');
ini_set('url_rewriter.tags', 'a=href');
echo '"<a href=\\u0022javascript:someFunc(\'some arg\')\\u0022>link 2</a>"';

Expected result:
----------------
Output for 5.6.30, 7.0.30 - 7.0.31
"<a href=\u0022javascript:someFunc('some arg')\u0022>link 2</a>"

Actual result:
--------------
Output for 7.1.0 - 7.3.0alpha4
"<a href=\u0022javascript:someFunc(?param_name=param_value'some arg')\u0022>link 2</a>"



(the added `?param_name=param_value` after the opening parenthesis causes a JavaScript error when the link is clicked.)