Bug 52355

Hello,

I'd like to start working on a bug,
https://bugs.php.net/bug.php?id=52355 but I'm not sure where to start
investigating exactly.

First of all, the effort is much appreciated :)

I've run a small test case and it seems the behaviour has been consistent
throughout most of PHP 4 and all of PHP 5: http://3v4l.org/8Q2F5

I've compared the 5.2.2 and 5.2.3 changes and there's nothing that
jumps into my eyes.
Could I get some pointers on how to start working on debugging this
and how to eventually fix it?
Also, while I'll fix this I plan to write an article about starting
from scratch and document every step in order to identify where the
bug is located and how to test/fix it so that others could use this
information.
Thanks.

Best regards

Florin Patan
https://github.com/dlsniper
http://www.linkedin.com/in/florinpatan

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Tjerk

Hello,

I'd like to start working on a bug,
https://bugs.php.net/bug.php?id=52355 but I'm not sure where to start
investigating exactly.
I've compared the 5.2.2 and 5.2.3 changes and there's nothing that
jumps into my eyes.
Could I get some pointers on how to start working on debugging this
and how to eventually fix it?
Also, while I'll fix this I plan to write an article about starting
from scratch and document every step in order to identify where the
bug is located and how to test/fix it so that others could use this
information.
Thanks.

Here is the implementation of the unary minus operator:
http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_language_parser.y#776
As you can see -a is translated to 0 - a.

In this particular case -0 is translated to 0 - 0, which is 0, not -0.

Hope this helps,
Nikita