parse error on browser back button???

[jrmatmillerclan]

As part of a project, I have two pages, A and B. A does a POST of some data to B; both pages work just fine.

However, when I'm testing page B and hit the browser's back button (just in case one of my users should do such an awful thing :-), I immediately get a PARSE ERROR message. No details, just "Parse error: parse error in <filename> on line <number>." I check the indicated place in the file, and there's nothing wrong -- as it happens, it's a // comment. Now, if I hit the browser's refresh button and approve the "is it ok to repost the page's contents again?" dialog, page A successfully loads, and is perfectly happy. Very weird.

It may or may not be helpful to note that:

• both A and B are pretty large files (~1700 lines), with a lot of PHP in them.

• I've tried increasing the amount of memory allocated to PHP from 8MB to 10MB in php.ini, but the error still happens.

• I'm running PHP 4.3.2 on RedHat 9. I've tried turning the Zend accelerator on and off, but the error happens in both cases.

• This is happening in several pages in my site/application, not just this one.

• In all these cases, the errors are always flagged at occurring at the same places in their respective files.

• I have an "approved" way of moving from B to A via a "breadcrumb"-type link and a Javascript-driven POST call, and this works just fine.

Does anybody have any clues? I'm baffled, myself. Is this a bug, perhaps?

Thanks,
Jim Miller

[jrmatmillerclan]

The one thing I didn't check in my previous note was -- duh -- different browsers. It turns out that the problem is specific to Safari on Mac; other browsers on Windows and Mac (and Linux, for that matter) are happy.

I'm still a little puzzled how some faulty back button code in Safari could cause an error in PHP's parser, but I'll leave that to someone else to figure out....