Simplify detection of the MAVEN_HOME and make it fully qualified

[rostidev]

The removed 'stripMHome' recursive function is not needed anymore.

Part of the 'mvn -version' output before this change:
Maven home: D:\develop\apache-maven-3.6.3\bin..

Same part of the 'mvn -version' output after this change:
Maven home: D:\develop\apache-maven-3.6.3
I.e. now it's fully qualified.

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[slachiewicz]

Thank you for contribution - could you also create Jira here: https://issues.apache.org/jira/browse/MNG ?

[rostidev]

Created a Jira issue about this improvement:
https://issues.apache.org/jira/browse/MNG-6837

[slachiewicz]

https://gitbox.apache.org/repos/asf?p=maven.git;a=commit;h=488a555a9796b64e926daf2fde076e6cf4492683

[slachiewicz]

looks good to me, anyone else can check also?

[rostidev]

I want to change this line in my commit:
set "MAVEN_HOME=%MAVEN_HOME:\bin\=%"

into this one:
set "MAVEN_HOME=%MAVEN_HOME:~0,-5%"

The reason: it's safer because theoretically the "\bin\" substring could appear more than once but we need to remove only the last one.

I will amend my commit and push force it.

[slachiewicz]

Quick question - what form where we use " should be better?
set "MAVEN_HOME=xxxx" or set MAVEN_HOME="xxxx"

[rostidev]

I just kept the original style of using " in set commands. But now I found that this is not only a matter of style but a mandatory requirement. Using set A="value with spaces" inserts the double quotes into the variable value and we don't want this. Using set "A=value with spaces" doesn't insert the double quotes into the variable value and this is good.

https://stackoverflow.com/questions/535975/dealing-with-quotes-in-windows-batch-scripts

[jira-importer]

Resolve #8451