Description:
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Securing PHP against accidentally opening a file/stream from a URL instead of the local filesystem is nice, however allow_url_fopen as it is, is just too limited, it needs an "explicit only" setting in addition to just "on" or "off".

In most real world situations, one doesn't want to forbid URL opening server wide, but it would be way nice if it didn't happen by accidental security oversight. So, what I'd really want is a setting that allows URL fopen only if I somehow explicitly tell the function I am using that it should expect a URL.

[Similar concerns are voiced in the responses here: http://bugs.php.net/bug.php?id=28684 The poster is asking for a different feature though, so continued this seperate request.]

Reproduce code:
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Would go something like this:

PHP.ini:
allow_url_fopen = explicit

Script:
//mode 'u' allows me to open from a URL

fopen(http://example.org/somefile.txt, 'ua+');
//-> should work fine

fopen(http://example.org/somefile.txt, 'a+');
//-> should give a "not allowed" error

Similar ought to go for all functions capable of URL opening, of course. A default of allow_url_fopen = On still maintains backwards compatibility.