Edit report at https://bugs.php.net/bug.php?id=64637&edit=1
ID: 64637
Comment by: phpmpan at mpan dot pl
Reported by: rstoll at tutteli dot ch
Summary: redefine NULL
Status: Feedback
Type: Bug
Package: *Languages/Translation
Operating System: windows
PHP Version: 5.4.7
Block user comment: N
Private report: N
New Comment:
The same issue applies to TRUE and FALSE.
Example:
define('TRUE', FALSE);
define('FALSE', TRUE);
var_dump(TRUE);
var_dump(FALSE);
Previous Comments:
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[2013-04-15 20:13:09] phpmpan at mpan dot pl
For some reason my earlier comment was not published here.
It contained a table of test results from 7 different PHP versions and 3 testing modes. I'll
have no time to rebuild the table now, but the point is that I confirmed the bug on Linux for
various PHP versions (including trunk snapshot). However, the bug appeared only in __interactive__
CLI mode, not in php -f or PHP run from Apache. It seems that any NULL spelling is
affected, except all-lowercase version. Also redefinition of particular spelling doesn't affect
other spellings, so one can define NuLl as 'x', nULL as 'y' and each of them
will keep their defined value.
I would also point out that a link provided by Laruence in the first comment outputs "hello
world" for some versions.
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[2013-04-15 09:07:11] rstoll at tutteli dot ch
I still got the "hello world" even without any extension. The output is slightly
different, I got NULL instead of null without xdebug. But still
NULL
NULL
NULL
string(11) "hello world"
Notice: Constant null already defined
for PHP 5.3.5 and PHP 5.4.7
In my opinion this bug can be closed because probably no one will ever do this.
As side mark, also http://3v4l.org/8knru does not show a notice
for the first define. Thus the implementation is not entirely correct. I assume your PHP version
behaves differently than mine in terms of symbol resolution. In my PHP version the case matters. So
if I write NULL a different symbol is resolved than when I write null. In your version always null
is resolved. That could be the reason why you do not get "hello world" as output. But I do
not really know the internals of PHP, it's just an assumption.
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[2013-04-15 03:04:09] laruence@php.net
please try again with a pure PHP (without any extension which will alter PHP
behavior, like xdebug, xhprof, apc/opcache, or taint)
thanks
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[2013-04-12 18:32:53] rstoll at tutteli dot ch
strange that you do not have the same problem. However, a notice should already be shown for the
first usage of define.
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[2013-04-12 16:57:14] anon at anon dot anon
Tested on PHP 5.3.5 on Windows and I just get NULL as output all four times, and then the notice.
Seems normal.
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