Quick tip for those of us unfortunate enough to have to deal with “legacy” php code (Ruby is Sooo much easier!).

One of my ISPs recently upgraded the PHP installation to 4.4.5 and suddenly my php application stopped. Nothing in the error log, no output to the browser.

I discovered that an attempt to session_register an unitialised variable causes that build of PHP to segfault.

For example…

Will cause a segfault

5d9eb9ee98fe285e9819dd3bc331abfb004

No segfault

5d9eb9ee98fe285e9819dd3bc331abfb005

I do not know if this is a generic issue or a consequence of the particular ISP’s build. But, I hope that this will help anyone else whose PHP application mysteriously stops!