ModelMapper.processJarPackage breaks on paths containing '+'

[laureanobrs]

Describe the bug

The ModelMapper.processJarPackage method uses URLDecoder.decode, which turns + into spaces, producing an invalid filesystem path.

That causes ModelMapper.initModelMap() to fail, so the prebuilt model map is left empty for built-in resources like v1/ConfigMap.

This use case stems from Bazel 8, where the format of canonical repo names has changed to use plus (+) instead of tilde (~):

.../external/rules_jvm_external++maven+maven/io/kubernetes/client-java-api/26.0.0/processed_client-java-api-26.0.0.jar

This seems related to #3981, but the trigger here is not a nested jar. It is a repository path containing +.

Client Version
26.0.0

Kubernetes Version
1.35.1

Java Version
Java 17

To Reproduce
NA

Expected behavior
Prebuilt model map is not empty and contains pre-built kubernetes models from classpath.

KubeConfig
NA

Server (please complete the following information):

• OS: -
• Environment: -
• Cloud: -

Additional context
NA

[laureanobrs]

One possible minimal-delta fix could be to encode the + ahead of time:

String jarFileName = URLDecoder.decode(packageURL.getFile().replace("+", "%2B"), StandardCharsets.UTF_8);

[brendandburns]

I'm trying to find the specification for a jar file reference, the best I have found is this:

https://docs.oracle.com/javase/8/docs/api/java/net/JarURLConnection.html

Which seems to indicate that the file is in fact a URL, which means that we should decode it, and the right solution would be for the + to be URL encoded before it is passed into the function.

Where are you getting your paths with + from? can you send an example?