Description:
------------
Related to the problems fixes in today's patches for substr_count() and substr_compare() there are issues with substr() and substr_replace().
Also there might be return value inconsistencies with strspn() and strcspn().

Reproduce code:
---------------
<?php

$v = 2147483647;  # INT_MAX on 32bit Linux

# Tries to allocate too much memory
var_dump(substr("abcde", 1, $v));
var_dump(substr_replace("abcde", "x", $v, $v));

# Functions with ill-defined behavior
var_dump(strspn("abcde", "abc", $v, $v)); # should return 0 but gives false
var_dump(strcspn("abcde", "abc", $v, $v)); # should return 0 but gives false

# Crashes
var_dump(substr_count("abcde", "abc", $v, $v));    # crashes <= 5.2.1. Fixed by Ilia http://news.php.net/php.cvs/43456
var_dump(substr_compare("abcde", "abc", $v, $v));  # crashes <= 5.2.1. Fixed by Stanislav http://news.php.net/php.cvs/43453

# Other tests (currently working)
var_dump(stripos("abcde", "abc", $v));
var_dump(substr_count("abcde", "abc", $v, 1));
var_dump(substr_count("abcde", "abc", 1, $v));
var_dump(strpos("abcde", "abc", $v));
var_dump(stripos("abcde", "abc", $v));
var_dump(strrpos("abcde", "abc", $v));
var_dump(strripos("abcde", "abc", $v));
var_dump(strncmp("abcde", "abc", $v));
var_dump(chunk_split("abcde", $v, "abc"));
var_dump(substr("abcde", $v, $v));
var_dump(str_repeat("a", $v+1));

?>