The implementations of the getPathMatcher in the default, zipfs, and jrtfs implementations have the following code:

int pos = syntaxAndInput.indexOf(':');
if (pos <= 0 || pos == syntaxAndInput.length())
    throw new IllegalArgumentException();

Checking pos == syntaxAndInput.length() is not needed here as pos is alway less than length.

First reported here:
https://mail.openjdk.org/pipermail/core-libs-dev/2022-April/088000.html