Demo for a symlink-related bug in jpackage (JDK-8352480)

Requirements

• Java 21+.
• macOS.

Description

In JDK-8274346, jpackage got a new parameter --app-content, which added the ability to configure arbitrary additional content for the app.

The implemented solution recursively copies the content and follows the symlinks, which it shouldn't do.

In my case, the additional content is another app bundle. Nesting app bundles a normal practice in macOS world.

App bundles actively use symlinks to manage framework versions, like this:

- My App.app
  - Contents
    - Frameworks
      - My Framework.framework
        - Versions
          - 134.0.6998.89 # This is actual version
            - My Framework # This is actual executable
          - Current # Symlink to 134.0.6998.89
          - My Framework # Symlink to the executable

When I add such a bundle to --app-content, jpackage materializes all symlinks which leads to an incorrect directory structure and respective codesign failure.

How to reproduce

1. Download Chromium bundle into build/additional-content:

   ./gradlew unpackChromiumBundle

   This will download the Chromium bundle into build/additional-content/Helpers.

2. Build the JAR file:

   ./gradlew jar

3. Execute jpackage:

   jpackage --app-version 1.0.0 \
        --app-content ./build/additional-content/Helpers \
        --dest ./build/jpackage-result \
        --input ./build/libs \
        --main-class App \
        --main-jar main.jar \
        --name "Nested bundles example" \
        --temp ./build/jpackage-temp \
        --type app-image \
        --mac-package-identifier com.example.nested.bundles \
        --mac-package-name "Nested bundles example" \
        --verbose

4. Once the command fails, take a look at the error:

   Caused by: java.io.IOException: Command
       [/usr/bin/codesign, -s, -, -vvvv, /.../jpackage-symlinks-bug/build/jpackage-result/Nested bundles example.app/Contents/Helpers/Chromium.app/Contents/MacOS/Chromium] exited with 1 code
   

5. Execute the command from the error message:

   /usr/bin/codesign -s - -vvvv \
        /.../jpackage-symlinks-bug/build/jpackage-result/Nested\ bundles\ example.app/Contents/Helpers/Chromium.app/Contents/MacOS/Chromium

6. See the cause of jpackage failure:

   /.../.../Helpers/Chromium.app/Contents/MacOS/Chromium: bundle format unrecognized, invalid, or unsuitable
   

7. Analyze the contents of result directory:

   # No symlinks will be found. Only materialized files.
   ls -Al build/jpackage-result/Nested bundles example.app/Contents/Helpers/Chromium.app/Contents/Frameworks/Chromium Framework.framework