TYPO3 Core

We wanted to keep directory names short and thus created two directories:
0
1
Funny thing is, Typo3 stopped listing further directories...

Why?
Because of using:
while($entry=$d->read()) {
instead of
while(false !==($entry=$d->read())) {
check http://php.net/manual/en/class.dir.php
and the comment there:
Please note the fashion in which dir::read()'s return value is checked in the example below. We are explicitly testing whether the return value is identical to (equal to and of the same type as - see Comparison Operators for more information) FALSE since otherwise, any directory entry whose name evaluates to FALSE will stop the loop.

This applies to all present Typo3 installations...

Files changed:
./class.t3lib_div.php
./class.t3lib_admin.php
./class.t3lib_tsparser_ext.php
./sysext/cms/tslib/class.tslib_content.php
./sysext/install/mod/class.tx_install.php
./class.file_list.inc
maybe more...

(issue imported from #M9527)