From 1c836f069860c91599adb6e535e879bc732e89d0 Mon Sep 17 00:00:00 2001
From: abilan <abilan@vmware.com>
Date: Mon, 12 Dec 2022 10:27:05 -0500
Subject: [PATCH] GH-3969: SFTP: Bring back support for empty path

Fixes https://github.com/spring-projects/spring-integration/issues/3969

In previous version for SFTP client (Jsch), the empty path for `LS` command
has meant a `user home`.
Turns out the MINA `SftpClient` does not support automatic user home resolution
from the empty path.

* Fix `SftpSession` to resolve an empty path into a user home via `canicalPath()` operation
---
 .../integration/sftp/session/SftpSession.java            | 1 +
 .../sftp/session/SftpRemoteFileTemplateTests.java        | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/SftpSession.java b/spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/SftpSession.java
index ee91eab20f..53a1a8dc5d 100644
--- a/spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/SftpSession.java
+++ b/spring-integration-sftp/src/main/java/org/springframework/integration/sftp/session/SftpSession.java
@@ -96,6 +96,7 @@ public class SftpSession implements Session<SftpClient.DirEntry> {
 				remoteDir = remotePath;
 			}
 		}
+		remoteDir = remoteDir.length() == 0 ? this.sftpClient.canonicalPath("") : remoteDir;
 		return StreamSupport.stream(this.sftpClient.readDir(remoteDir).spliterator(), false)
 				.filter((entry) -> !isPattern || PatternMatchUtils.simpleMatch(remoteFile, entry.getFilename()));
 	}
diff --git a/spring-integration-sftp/src/test/java/org/springframework/integration/sftp/session/SftpRemoteFileTemplateTests.java b/spring-integration-sftp/src/test/java/org/springframework/integration/sftp/session/SftpRemoteFileTemplateTests.java
index 2770e22182..a515ef891e 100644
--- a/spring-integration-sftp/src/test/java/org/springframework/integration/sftp/session/SftpRemoteFileTemplateTests.java
+++ b/spring-integration-sftp/src/test/java/org/springframework/integration/sftp/session/SftpRemoteFileTemplateTests.java
@@ -32,6 +32,7 @@ import org.springframework.integration.file.DefaultFileNameGenerator;
 import org.springframework.integration.file.remote.ClientCallbackWithoutResult;
 import org.springframework.integration.file.remote.SessionCallbackWithoutResult;
 import org.springframework.integration.file.remote.session.CachingSessionFactory;
+import org.springframework.integration.file.remote.session.Session;
 import org.springframework.integration.file.remote.session.SessionFactory;
 import org.springframework.integration.file.support.FileExistsMode;
 import org.springframework.integration.sftp.SftpTestSupport;
@@ -124,6 +125,14 @@ public class SftpRemoteFileTemplateTests extends SftpTestSupport {
 		sessionFactory.destroy();
 	}
 
+	@Test
+	public void lsUserHome() throws IOException {
+		try (Session<SftpClient.DirEntry> session = this.sessionFactory.getSession()) {
+			String[] entries = session.listNames("");
+			assertThat(entries).contains(".", "sftpSource", "sftpTarget");
+		}
+	}
+
 	@Configuration
 	public static class Config {