Dots and spaces in variable names are converted to underscores. For
example <input name="a.b" /> becomes $_POST["a_b"].
Any reason why? and any way to modify this behaviour to preserve dots
and spaces? (dots specifically)
I'm also using dots for this reason, so I feel your pain. What I ended up doing is converting dot syntax to PHP array syntax as I compile my templates.
So when I type this: <input ... name="a.b.c.d"> what I get actually compiled and sent to the browser is this: <intput ... name="a[b][c][d]">
The reason for this quirk is register_globals. The symbols not suitable for symbol names, such as dots, are replaced with underscores, so that you can access your POST variable "foo.bar" as $foo_bar in global space. Of course it never made sense the conversion is applied to the superglobals like $_COOKIE/GET/POST, but it was, and now there are claims that it'll break backwards compatibility if changed.
I hope PHP6 will remove this processing as register_globals will be completely removed at that point.
Regards,
Stan Vassilev