Maven wrapper broken with maven 4.0.0-beta-5 and above (solved issue included)

[hazendaz]

Affected version

4.0.0-beta-5, 4.0.0-rc-1, 4.0.0-rc-2, 4.0.0-rc-3, 4.0.0-rc-4

Bug description

See apache/maven-wrapper#325 for further details and issue.

Maven 4.0.0-beta-5 and above changed to use selective MAVEN_MAIN_CLASS. Because maven wrapper very closely mimics mavens own mvn and mvn.cmd, any changes would need ported to the maven wrapper. However, to some degree that breaks backwards compatibility since its a maven 4 item only but would work by fixing wrapper as noted (probably more than I did). I think it would be better though to add the defaulting when missing inside maven itself rather than expect the script pass a defaulted value along so that there is no breaking maven wrapper.

This line

if "%MAVEN_MAIN_CLASS%"=="" @set MAVEN_MAIN_CLASS=org.apache.maven.cling.MavenCling

Can we do this inside maven itself when missing instead? That would immediately fix the maven wrapper issue. Since its the internals throwing errors, I suspect that answer is yes.

[DidierLoiseau]

This looks similar to the issue I was mentioning in #1750 (comment)

To which @gnodet replied with:

I suppose we could make it default to org.apache.maven.cling.MavenCling ...