Strengthen base URI transaction regression test

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/RDF4JProtocolSession.java

@@ -1069,9 +1069,11 @@ protected void upload(HttpEntity reqEntity, String baseURI, boolean overwrite, b
 			for (String encodedContext : Protocol.encodeContexts(contexts)) {
 				url.addParameter(Protocol.CONTEXT_PARAM_NAME, encodedContext);
 			}
-			if (baseURI != null && !baseURI.trim().isEmpty()) {
-				String encodedBaseURI = Protocol.encodeValue(SimpleValueFactory.getInstance().createIRI(baseURI));
-				url.setParameter(Protocol.BASEURI_PARAM_NAME, encodedBaseURI);
+			if (baseURI != null) {
+				String trimmedBaseURI = baseURI.trim();
+				if (!trimmedBaseURI.isEmpty()) {
+					url.setParameter(Protocol.BASEURI_PARAM_NAME, trimmedBaseURI);
+				}
 			}
 			if (preserveNodeIds) {
 				url.setParameter(Protocol.PRESERVE_BNODE_ID_PARAM_NAME, "true");

core/http/client/src/test/java/org/eclipse/rdf4j/http/client/RDF4JProtocolSessionTest.java

@@ -15,6 +15,7 @@
 import static org.mockserver.model.HttpResponse.response;
 
 import java.io.ByteArrayInputStream;
+import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 
@@ -184,6 +185,52 @@ public void testRemoveDataTransactionFollowsRedirectOnDelete(MockServerClient cl
 		);
 	}
 
+	@Test
+	public void testAddDataTransactionUsesPlainBaseURI(MockServerClient client) throws Exception {
+		RDF4JProtocolSession session = getRDF4JSession();
+
+		String transactionsLocation = Protocol.getTransactionsLocation(session.getRepositoryURL());
+		URI transactionsURI = URI.create(transactionsLocation);
+		String transactionLocation = transactionsLocation + "/1";
+		URI transactionURI = URI.create(transactionLocation);
+
+		client.when(
+				request()
+						.withMethod("POST")
+						.withPath(transactionsURI.getPath()),
+				Times.once())
+				.respond(response().withStatusCode(201).withHeader("Location", transactionLocation));
+
+		client.when(
+				request()
+						.withMethod("PUT")
+						.withPath(transactionURI.getPath())
+						.withQueryStringParameter("action", "ADD"),
+				Times.once())
+				.respond(response().withStatusCode(204));
+
+		session.beginTransaction(IsolationLevels.SERIALIZABLE);
+
+		String baseIRI = "http://example.com/";
+		ByteArrayInputStream data = new ByteArrayInputStream("<foo> <bar> <baz> ."
+				.getBytes(StandardCharsets.UTF_8));
+		session.addData(data, baseIRI, RDFFormat.TURTLE);
+
+		client.verify(
+				request()
+						.withMethod("PUT")
+						.withPath(transactionURI.getPath())
+						.withQueryStringParameter("baseURI", baseIRI),
+				VerificationTimes.once());
+
+		HttpRequest[] recordedRequests = client.retrieveRecordedRequests(
+				request().withMethod("PUT")
+						.withPath(transactionURI.getPath())
+						.withQueryStringParameter("action", "ADD"));
+		assertThat(recordedRequests).hasSize(1);
+		assertThat(recordedRequests[0].getFirstQueryStringParameter("baseURI")).isEqualTo(baseIRI);
+	}
+
 	@Test
 	public void testUpdateRepositoryExecutesPost(MockServerClient client) throws Exception {
 		RepositoryConfig config = new RepositoryConfig("test");

tools/server/src/test/java/org/eclipse/rdf4j/http/server/RemoteRepositoryBaseUriIT.java

@@ -0,0 +1,90 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Eclipse RDF4J contributors.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Distribution License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ ******************************************************************************/
+package org.eclipse.rdf4j.http.server;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.ByteArrayInputStream;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.eclipse.rdf4j.http.protocol.Protocol;
+import org.eclipse.rdf4j.model.Statement;
+import org.eclipse.rdf4j.model.util.Values;
+import org.eclipse.rdf4j.model.vocabulary.RDF;
+import org.eclipse.rdf4j.repository.Repository;
+import org.eclipse.rdf4j.repository.RepositoryConnection;
+import org.eclipse.rdf4j.repository.http.HTTPRepository;
+import org.eclipse.rdf4j.rio.RDFFormat;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+public class RemoteRepositoryBaseUriIT {
+
+	private static TestServer server;
+
+	@BeforeAll
+	public static void startServer() throws Exception {
+		server = new TestServer();
+		try {
+			server.start();
+		} catch (Exception e) {
+			server.stop();
+			throw e;
+		}
+	}
+
+	@AfterAll
+	public static void stopServer() throws Exception {
+		server.stop();
+	}
+
+	@Test
+	public void testAddDataUsesPlainBaseURI() throws Exception {
+		Repository repository = new HTTPRepository(
+				Protocol.getRepositoryLocation(TestServer.SERVER_URL, TestServer.TEST_REPO_ID));
+
+		try (RepositoryConnection connection = repository.getConnection()) {
+			connection.begin();
+			connection.clear();
+			connection.commit();
+		}
+
+		String baseIRI = "http://example.com/base/";
+		String rdfXml = String.join("\n",
+				"<?xml version=\"1.0\"?>",
+				"<rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">",
+				"    <rdf:Description rdf:about=\"relative\">",
+				"        <rdf:type rdf:resource=\"http://example.com/Type\" />",
+				"    </rdf:Description>",
+				"</rdf:RDF>");
+
+		try (RepositoryConnection connection = repository.getConnection()) {
+			connection.begin();
+			connection.add(new ByteArrayInputStream(rdfXml.getBytes(java.nio.charset.StandardCharsets.UTF_8)), baseIRI,
+					RDFFormat.RDFXML);
+			connection.commit();
+		}
+
+		try (RepositoryConnection connection = repository.getConnection()) {
+			List<Statement> statements = connection.getStatements(null, null, null, false)
+					.stream()
+					.collect(Collectors.toList());
+
+			assertThat(statements).hasSize(1);
+			Statement statement = statements.get(0);
+			assertThat(statement.getSubject()).isEqualTo(Values.iri(baseIRI + "relative"));
+			assertThat(statement.getPredicate()).isEqualTo(RDF.TYPE);
+			assertThat(statement.getObject()).isEqualTo(Values.iri("http://example.com/Type"));
+		}
+	}
+}