RFD: Use of ~ (tilde) when considering local and non-local file URLs

[Eirik Bjørsnøs]

Hi,

Various URL scheme code paths contain branches for local or non-local file
URLs:

See URLJarFile::isFileURL for an example where the host is compared as
follows:

String host = url.getHost();
if (host == null || host.isEmpty() || host.equals("~") ||
    host.equalsIgnoreCase("localhost"))
    return true;


Equivalent checks are found in unix and windows Handler::openConnection.

In JarFileFactory::urlFor however, the logic is slightly different in that
the comparison with ~ (tilde) is missing:

String host = url.getHost();
if (host != null && !host.isEmpty() &&
        !host.equalsIgnoreCase("localhost")) {

I have tried to find an RFC or any other mention of "~" in host names, but
found nothing. Can anyone shine light on the meaning and interpretation of
this character as a host name?

In any case, I think if we could add the tilde logic
to JarFileFactory::urlFor, then all these four checks would be equivalent
and a prime candidate for a consolidating cleanup PR, perhaps also
expanding a bit on the documentation for the consolidated method(s).

My take is that the missing test was a simple oversight, that adding it
should not be harmful and that this would enable a nice consolidation of
this particular logic. .

Thoughts?

Eirik.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/net-dev/attachments/20250326/e6b28410/attachment.htm>