Class-Path (in jar file) semantics different between Java 11 and 13 (on Windows)?

[Alan Bateman]

On 19/11/2019 20:22, David Lloyd wrote:
> :
> Where can the updated specification be found?  It has in the past been
> clearly specified and well understood that class path entries are
> interpreted as relative URLs.  If that has changed then this will
> definitely break Quarkus and perhaps other applications as well.
>
> A Google search for "JAR file specification" only seems to turn up
> older versions (JDK 10 and earlier).
One way to quickly get to it is type "java.util.jar" into the javadoc 
search box and it is linked from the package description. So for the JDK 
13 published on jdk.java.net it is:
https://docs.oracle.com/en/java/javase/13/docs/specs/jar/jar.html#class-path-attribute

The value is a relative URL, same as always, it's just that the 
implementation is less tolerant of bad input. The stricter checking has 
been in place for a few releases, controlled by the system property 
mentioned in the discussion here.

It's always hard to dial up checking after the fact and one of the main 
challenges has been mis-uses where tools have been putting file paths 
(rather than URL) or absolute URLs into the value. This is the reason 
why the spec now allows absolute file URLs (need to specify the "file:" 
scheme).

-Alan