Fail deployment on presence of an hibernate.properties resource

extensions/hibernate-orm/deployment/src/main/java/io/quarkus/hibernate/orm/deployment/HibernateOrmProcessor.java

@@ -9,11 +9,13 @@
 import static org.hibernate.cfg.AvailableSettings.USE_SECOND_LEVEL_CACHE;
 
 import java.io.IOException;
+import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
@@ -423,6 +425,7 @@ public void build(RecorderContext recorderContext, HibernateOrmRecorder recorder
             BuildProducer<BeanContainerListenerBuildItem> beanContainerListener) throws Exception {
 
         feature.produce(new FeatureBuildItem(Feature.HIBERNATE_ORM));
+        validateHibernatePropertiesNotUsed();
 
         final boolean enableORM = hasEntities(jpaModel);
         final boolean hibernateReactivePresent = capabilities.isPresent(Capability.HIBERNATE_REACTIVE);
@@ -472,6 +475,22 @@ public void build(RecorderContext recorderContext, HibernateOrmRecorder recorder
                                 proxyDefinitions.getProxies())));
     }
 
+    private void validateHibernatePropertiesNotUsed() {
+        try {
+            final Enumeration<URL> resources = Thread.currentThread().getContextClassLoader().getResources(
+                    "hibernate.properties");
+            if (resources.hasMoreElements()) {
+                final URL url = resources.nextElement();
+                throw new IllegalStateException(
+                        "The Hibernate ORM configuration in Quarkus does not support sourcing configuration properties from resources named `hibernate.properties`,"
+                                + " and this is now expressly prohibited as such a file could lead to unpredictable semantics. Please remove it from `"
+                                + url.toExternalForm() + '`');
+            }
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     @BuildStep
     void handleNativeImageImportSql(BuildProducer<NativeImageResourceBuildItem> resources,
             List<PersistenceUnitDescriptorBuildItem> descriptors,

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/config/NoHibernatePropertiesTest.java

@@ -0,0 +1,42 @@
+package io.quarkus.hibernate.orm.config;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusUnitTest;
+
+/**
+ * Since we decided that we're no longer supporting to read an hibernate.properties resource,
+ * let's also test that this is made explicit.
+ * N.B. while we no longer parse the file during boot, there are other components in Hibernate ORM
+ * that look for it so this would lead to inconsistencies.
+ */
+public class NoHibernatePropertiesTest {
+
+    @RegisterExtension
+    static QuarkusUnitTest runner = new QuarkusUnitTest()
+            .assertException(t -> {
+                assertThat(t)
+                        .isInstanceOf(IllegalStateException.class)
+                        .hasMessageContainingAll(
+                                "The Hibernate ORM configuration in Quarkus does not support sourcing configuration properties from resources named `hibernate.properties`");
+            })
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
+                    .addClass(MyEntity.class)
+                    .addAsResource(new StringAsset(""), "hibernate.properties")
+                    .addAsResource("application.properties"))
+            .overrideConfigKey("quarkus.datasource.devservices", "false");
+
+    @Test
+    public void testInvalidConfiguration() {
+        // deployment exception should happen first
+        Assertions.fail();
+    }
+
+}