From 139536988b7a34226eba1cb22cc7aec38b6f7762 Mon Sep 17 00:00:00 2001
From: Manuel Fuchs <manuel.fuchs@salesforce.com>
Date: Thu, 19 Dec 2024 17:55:28 +0100
Subject: [PATCH] Fix JDK overlay directory

---
 buildpacks/jvm/CHANGELOG.md                 |  4 ++
 buildpacks/jvm/src/constants.rs             |  2 +-
 buildpacks/jvm/tests/integration/main.rs    |  1 +
 buildpacks/jvm/tests/integration/overlay.rs | 42 +++++++++++++++++++++
 4 files changed, 48 insertions(+), 1 deletion(-)
 create mode 100644 buildpacks/jvm/tests/integration/overlay.rs

diff --git a/buildpacks/jvm/CHANGELOG.md b/buildpacks/jvm/CHANGELOG.md
index 0b7365e5..9d36c1e5 100644
--- a/buildpacks/jvm/CHANGELOG.md
+++ b/buildpacks/jvm/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- JDK overlays are now properly sourced from the `.jdk-overlay` directory instead of `.jdk_overlay`. ([#763](https://github.com/heroku/buildpacks-jvm/pull/763))
+
 ## [6.0.4] - 2024-12-05
 
 ### Added
diff --git a/buildpacks/jvm/src/constants.rs b/buildpacks/jvm/src/constants.rs
index ea6ce060..29d8b737 100644
--- a/buildpacks/jvm/src/constants.rs
+++ b/buildpacks/jvm/src/constants.rs
@@ -1,4 +1,4 @@
 pub(crate) const JAVA_TOOL_OPTIONS_ENV_VAR_DELIMITER: &str = " ";
 pub(crate) const JAVA_TOOL_OPTIONS_ENV_VAR_NAME: &str = "JAVA_TOOL_OPTIONS";
-pub(crate) const JDK_OVERLAY_DIR_NAME: &str = ".jdk_overlay";
+pub(crate) const JDK_OVERLAY_DIR_NAME: &str = ".jdk-overlay";
 pub(crate) const OPENJDK_LATEST_LTS_VERSION: u32 = 21;
diff --git a/buildpacks/jvm/tests/integration/main.rs b/buildpacks/jvm/tests/integration/main.rs
index 16d472a2..e2706164 100644
--- a/buildpacks/jvm/tests/integration/main.rs
+++ b/buildpacks/jvm/tests/integration/main.rs
@@ -11,6 +11,7 @@
 use libcnb_test::BuildConfig;
 use std::path::Path;
 
+mod overlay;
 mod versions;
 
 fn default_build_config(fixture_path: impl AsRef<Path>) -> BuildConfig {
diff --git a/buildpacks/jvm/tests/integration/overlay.rs b/buildpacks/jvm/tests/integration/overlay.rs
new file mode 100644
index 00000000..e26b6546
--- /dev/null
+++ b/buildpacks/jvm/tests/integration/overlay.rs
@@ -0,0 +1,42 @@
+use crate::default_build_config;
+use libcnb_test::{assert_contains, TestRunner};
+use std::path::PathBuf;
+
+#[test]
+#[ignore = "integration test"]
+fn overlay() {
+    const ADDITIONAL_PATH: &str = "earth.txt";
+    const ADDITIONAL_CONTENTS: &str = "Un diminuto punto azul";
+
+    const CACERTS_PATH: &str = "lib/security/cacerts";
+    const CACERTS_CONTENTS: &str = "overwritten";
+
+    TestRunner::default().build(
+        default_build_config("test-apps/java-21-app").app_dir_preprocessor(|app_dir| {
+            let overlay_path = app_dir.join(".jdk-overlay");
+            std::fs::create_dir_all(&overlay_path).unwrap();
+            std::fs::write(overlay_path.join(ADDITIONAL_PATH), ADDITIONAL_CONTENTS).unwrap();
+
+            let cacerts_path = overlay_path.join(PathBuf::from(CACERTS_PATH));
+            std::fs::create_dir_all(&cacerts_path.parent().unwrap()).unwrap();
+            std::fs::write(&cacerts_path, CACERTS_CONTENTS).unwrap();
+        }),
+        |context| {
+            // Validate that adding a new file works
+            assert_contains!(
+                context
+                    .run_shell_command(format!("cat $JAVA_HOME/{ADDITIONAL_PATH}"))
+                    .stdout,
+                ADDITIONAL_CONTENTS
+            );
+
+            // Validate that overwriting a file works
+            assert_contains!(
+                context
+                    .run_shell_command(format!("cat $JAVA_HOME/{CACERTS_PATH}"))
+                    .stdout,
+                CACERTS_CONTENTS
+            );
+        },
+    );
+}