Description:
------------
Due to an uncaught integer overflow, PDO::quote() of PDO_SQLite
may return a not properly quoted string.  The exact details likely
depend on the implementation of sqlite3_snprintf(), but with
recent versions (tested sqlite 3.39.2 and sqlite 3.39.4) it is
possible to force the function to return a single apostrophe, if
the function is called on user supplied input without any length
restrictions in place (common memory_limit settings should prevent
that though, and usually also post_max_size etc.)

The problem is that the length parameter of sqlite3_snprintf() is
of type int, but we're passing an unrestricted zend_long value, so
overflow may occur.  This renders the previous safe_emalloc()
practically useless, since it only prevents overflow of size_t
values.  For 32bit architecture (where we assume sizeof(zend_long)
== sizeof(int)) this is not a problem, but for 64bit architectures
it is, as the given test script demonstrates.


Test script:
---------------
<?php
$pdo = new PDO("sqlite::memory:");
$string = str_repeat("a", 0x80000000);
var_dump($pdo->quote($string));
?>

Expected result:
----------------
A properly quoted string, false, or some other error indication.

Actual result:
--------------
string(1) "'"