Workaround: Windows Junction Link handling issue in mvnw.cmd

[fp024]

hello.

I applied to join Apache JIRA, but I wasn't sure if I would be approved as a member, so I submitted a PR for issue reporting purposes.

Issue

Move-Item fails when the .m2 path is in the following state:

• Junction link reference status of m2 directory on my system
  
  • G:\Maven\.m2 is the actual path.

The argument value of -Destnation in PowerShell's Move-Item command must be an actual path, but in my environment, it is a junction link and is bound to fail.

Workaround

So I modified the code to get $MAVEN_HOME_PARENT as follows.

# ...
$MAVEN_M2_PATH = "$HOME/.m2"
if ($env:MAVEN_USER_HOME) {
  $MAVEN_M2_PATH = "$env:MAVEN_USER_HOME"
}

if (-not (Test-Path -Path $MAVEN_M2_PATH)) {
    New-Item -Path $MAVEN_M2_PATH -ItemType Directory | Out-Null
}

$MAVEN_WRAPPER_DISTS = $null
if ((Get-Item $MAVEN_M2_PATH).Target -eq $null) {
  $MAVEN_WRAPPER_DISTS = "$MAVEN_M2_PATH/wrapper/dists"
} else {
  $MAVEN_WRAPPER_DISTS = (Get-Item $MAVEN_M2_PATH).Target[0] + "/wrapper/dists"
}

$MAVEN_HOME_PARENT = "$MAVEN_WRAPPER_DISTS/$distributionUrlNameMain"
# ...

• The actual path could be obtained by obtaining Target[0] on the Item obtained with Get-Item -Path {Path}.

  • If the path passed as an argument is an actual path rather than a junction link path, it is $null.

This PR commit was posted for issue reporting purposes only, so it may require expert editing.

Please confirm. thank you have a good day. 👍

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[cstamas]

@michael-o ping

[fp024]

hello.

I received a GitHub Action build failure email and checked the code again.

Here's what I saw in PowerShell ISE after separating that part:

# Set MAVEN_USER_HOME manually
# $env:MAVEN_USER_HOME="D:/MAVEN2/.m2"
$env:MAVEN_USER_HOME=$null

$MAVEN_M2_PATH = "$HOME/.m2"
if ($env:MAVEN_USER_HOME) {
  $MAVEN_M2_PATH = "$env:MAVEN_USER_HOME"
}
Write-Output "MAVEN_M2_PATH: $MAVEN_M2_PATH"

if (-not (Test-Path -Path $MAVEN_M2_PATH)) {
    New-Item -Path $MAVEN_M2_PATH -ItemType Directory | Out-Null
}

$MAVEN_WRAPPER_DISTS = $null
if ((Get-Item $MAVEN_M2_PATH).Target[0] -eq $null) { # 💡Re-edited part
  Write-Output "is null: actual path"
  $MAVEN_WRAPPER_DISTS = "$MAVEN_M2_PATH/wrapper/dists"
  Write-Output "MAVEN_WRAPPER_DISTS: $MAVEN_WRAPPER_DISTS"
} else {
  $MAVEN_WRAPPER_DISTS = (Get-Item $MAVEN_M2_PATH).Target[0] + "/wrapper/dists"
  Write-Output "not null: junction path -> actual path"
  Write-Output "MAVEN_WRAPPER_DISTS: $MAVEN_WRAPPER_DISTS"
}

When MAVEN_USER_HOME is not set as an environment variable

• MAVEN_M2_PATH="HOME/.m2"

• C:\Users\{UserName}/.m2 is the junction path
  • G:\Maven\m2/wrapper/dists is the actual path
  • The actual path to the picture in the first comment is incorrect: my actual path environment is G:\Maven\m2, not G:\Maven\.m2.

When MAVEN_USER_HOME is set as an environment variable

• MAVEN_M2_PATH="D:/MAVEN2/.m2"
  • D:/MAVEN2/.m2 is the actual path

• Compared to the first uploaded commit, we changed it to always check the junction link condition with Target[0].
  • https://github.com/apache/maven-wrapper/compare/eaddcc6d7d1490059e286eef80a2176e560e3d6e..cefb22592fe3397c7652bc3a3866bd73cf5ec8c5

thank you 👍