[PHP-BUG] Bug #71598 [NEW]: Whitespace at the start of a function name counts as part of the function name.

From:             lucas at lucassifoni dot info
Operating system: Debian 8
PHP version:      7.0.3
Package:          PHP Language Specification
Bug Type:         Bug
Bug description:Whitespace at the start of a function name counts as part of the function name.

Description:
------------
According to the PHP doc, «A valid function name starts with a letter
or underscore, followed by any number of letters, numbers, or
underscores.»

Some whitespace characters, like U+2000, U+2001, U+2002, U+2003, U+2004
[...], and the zero-width non breaking space (now word joiner, U+FEFF),
are interpreted as a part of a function name.

If this isn't a problem with a proper code editor that highlights
"special" whitespace, it is still conflicting with the doc, and can be
really confusing to users.

The given snippet has a zero-width nonbreaking space just in front of
foo(). When invoking foo(), the function is undefined, since the space
is part of its referenced name.

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

function foo(){
    echo 'bar';
}

foo();

Expected result:
----------------
bar

Actual result:
--------------
Fatal error: Uncaught Error: Call to undefined function foo() in
[...][...]:7 Stack trace: #0 {main} thrown in [...][...] on line 7 

-- 
Edit bug report at https://bugs.php.net/bug.php?id=71598&edit=1
-- 
Try a snapshot (PHP 5.4):   https://bugs.php.net/fix.php?id=71598&r=trysnapshot54
Try a snapshot (PHP 5.5):   https://bugs.php.net/fix.php?id=71598&r=trysnapshot55
Try a snapshot (trunk):     https://bugs.php.net/fix.php?id=71598&r=trysnapshottrunk
Fixed in SVN:               https://bugs.php.net/fix.php?id=71598&r=fixed
Fixed in release:           https://bugs.php.net/fix.php?id=71598&r=alreadyfixed
Need backtrace:             https://bugs.php.net/fix.php?id=71598&r=needtrace
Need Reproduce Script:      https://bugs.php.net/fix.php?id=71598&r=needscript
Try newer version:          https://bugs.php.net/fix.php?id=71598&r=oldversion
Not developer issue:        https://bugs.php.net/fix.php?id=71598&r=support
Expected behavior:          https://bugs.php.net/fix.php?id=71598&r=notwrong
Not enough info:            https://bugs.php.net/fix.php?id=71598&r=notenoughinfo
Submitted twice:            https://bugs.php.net/fix.php?id=71598&r=submittedtwice
register_globals:           https://bugs.php.net/fix.php?id=71598&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=71598&r=php4
Daylight Savings:           https://bugs.php.net/fix.php?id=71598&r=dst
IIS Stability:              https://bugs.php.net/fix.php?id=71598&r=isapi
Install GNU Sed:            https://bugs.php.net/fix.php?id=71598&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=71598&r=float
No Zend Extensions:         https://bugs.php.net/fix.php?id=71598&r=nozend
MySQL Configuration Error:  https://bugs.php.net/fix.php?id=71598&r=mysqlcfg