php-src/README.PHP4-TO-PHP5-THIN-CHANGES

1. strr(i)pos() now uses the full needle when searching - be aware that code that previous have run now can stop working.
   EX :
   <?php
   var_dump(strrpos("ABCDEF","DEF"));
   var_dump(strrpos("ABCDEF","DAF"));
   ?>
   Will give you differents results. The diffence is in the second cal to strrpos(). The same applies and for strripos().

2. Change illegal use of string offset from E_WARNING to E_ERROR
   EX :
   marcus@zaphod /usr/src/php5 $ sapi/cli/php -r '$a = "foo"; unset($a[0][1][2]);'
   Fatal error: Cannot use string offset as an array in Command line code on line 1

3. array_merge() accepts only arrays. If non-array is passed a E_WARNING for every non-array
   parameter will be throwed. Be careful because your code may start emitting E_WARNING out of the blue.

4. Be careful when porting from ext/mysql to ext/mysqli. mysqli_fetch_row()/mysqli_fetch_array()/mysql_fetch_assoc()
   retun NULL when there is no more data in the result set (ext/mysql's functions return FALSE).