Description:
------------
strip_tags() will clobber all remaining input after encountering non-HTML tags, regardless if embedded in "allowable-tags".

When strip_tags() encounters a "<" followed by *any non-whitespace*, it assumes it's an HTML tag, even if it couldn't legally be one.  In the example below, even something as simple as a "<=" appearing in JavaScript is enough to trigger the behavior.


For a full list of characters that strip_tags() clobbers on, see this example: http://ideone.com/BEPINI

Test script:
---------------
<?php

// Example 1: Without <=
$code = "<script>if (foo >= bar){ alert(0); }</script>";
var_dump(strip_tags($code));
var_dump(strip_tags($code, "<script>"));

// Example 2: With <=
$code = "<script>if (foo <= bar){ alert(0); }</script>";
var_dump(strip_tags($code));
var_dump(strip_tags($code, "<script>"));

?>

Expected result:
----------------
string(28) "if (foo >= bar){ alert(0); }"
string(45) "<script>if (foo >= bar){ alert(0); }</script>"

string(28) "if (foo <= bar){ alert(0); }"
string(45) "<script>if (foo <= bar){ alert(0); }</script>"

Actual result:
--------------
string(28) "if (foo >= bar){ alert(0); }"
string(45) "<script>if (foo >= bar){ alert(0); }</script>"

string(8) "if (foo "
string(16) "<script>if (foo "