Honor configured shell for remote exec

tests/integration_smoke.rs

@@ -1355,6 +1355,22 @@ fn native_exec_command_smoke() {
     let dir = tempfile::tempdir().unwrap();
     let port = free_udp_port();
     let config = write_server_config(&dir, port);
+    let shell_log = dir.path().join("exec-shell.log");
+    let shell = dir.path().join("exec-shell");
+    fs::write(
+        &shell,
+        format!(
+            "#!/bin/sh\nprintf '%s\\n' \"$*\" >> '{}'\nexec /bin/sh \"$@\"\n",
+            shell_log.display()
+        ),
+    )
+    .unwrap();
+    fs::set_permissions(&shell, fs::Permissions::from_mode(0o700)).unwrap();
+    let raw = fs::read_to_string(&config).unwrap().replace(
+        "shell = \"/bin/sh\"",
+        &format!("shell = {:?}", shell.display().to_string()),
+    );
+    fs::write(&config, raw).unwrap();
     write_native_client_auth(&dir, &config);
     let mut server = start_server(&dir, &config);
     let client_bin = env!("CARGO_BIN_EXE_dosh-client");
@@ -1380,6 +1396,19 @@ fn native_exec_command_smoke() {
     );
     assert_eq!(String::from_utf8_lossy(&output.stdout), "out");
     assert_eq!(String::from_utf8_lossy(&output.stderr), "err");
+    let shell_invocations = fs::read_to_string(shell_log).unwrap();
+    assert!(
+        shell_invocations
+            .lines()
+            .any(|line| line.starts_with("-c ")),
+        "configured shell was not used for exec: {shell_invocations:?}"
+    );
+    assert!(
+        !shell_invocations
+            .lines()
+            .any(|line| line.starts_with("-lc ")),
+        "exec must not start a login shell: {shell_invocations:?}"
+    );
 }
 
 #[test]