Add realpath variants of the commands that return paths.

Closes #1670.

test/Makefile.am

@@ -51,6 +51,8 @@ rtorrent_Test_Src_SOURCES = $(rtorrent_Test_Common) \
 	src/test_command_dynamic.h \
 	src/test_command_local.cc \
 	src/test_command_local.h \
+	src/test_command_path.cc \
+	src/test_command_path.h \
 	src/test_command_string.cc \
 	src/test_command_string.h \
 	src/test_watch_ready_queue.cc \

test/src/test_command_path.cc

@@ -0,0 +1,116 @@
+#include "config.h"
+
+#include "test/src/test_command_path.h"
+
+#include <cstdlib>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <torrent/exceptions.h>
+#include <torrent/torrent.h>
+
+#include "control.h"
+#include "globals.h"
+#include "rpc/parse_commands.h"
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestCommandPath);
+
+void initialize_command_local();
+
+void
+TestCommandPath::setUp() {
+  char temp_dir[] = "/tmp/rtorrent_test_path_XXXXXX";
+
+  CPPUNIT_ASSERT(mkdtemp(temp_dir) != nullptr);
+
+  // The temporary directory itself may sit behind a symlink, as /tmp does on
+  // macOS, so resolve it up front to keep the expected values exact.
+  m_temp_dir = resolve_path(temp_dir);
+
+  CPPUNIT_ASSERT(!m_temp_dir.empty());
+  CPPUNIT_ASSERT_EQUAL(0, mkdir((m_temp_dir + "/data").c_str(), 0755));
+  CPPUNIT_ASSERT_EQUAL(0, symlink((m_temp_dir + "/data").c_str(), (m_temp_dir + "/link").c_str()));
+}
+
+void
+TestCommandPath::tearDown() {
+  unlink((m_temp_dir + "/link").c_str());
+  rmdir((m_temp_dir + "/data").c_str());
+  rmdir(m_temp_dir.c_str());
+}
+
+void
+TestCommandPath::test_resolves_symlink() {
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", resolve_path(m_temp_dir + "/link"));
+
+  // A path that lies below a symlinked directory is resolved as well.
+  CPPUNIT_ASSERT_EQUAL(0, mkdir((m_temp_dir + "/data/below").c_str(), 0755));
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data/below", resolve_path(m_temp_dir + "/link/below"));
+  rmdir((m_temp_dir + "/data/below").c_str());
+}
+
+void
+TestCommandPath::test_removes_relative_components() {
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir, resolve_path(m_temp_dir + "/data/.."));
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", resolve_path(m_temp_dir + "/./data"));
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", resolve_path(m_temp_dir + "/data/"));
+
+  // Trailing slashes and duplicated separators collapse.
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", resolve_path(m_temp_dir + "//data//"));
+}
+
+void
+TestCommandPath::test_expands_tilde() {
+  const char* home = std::getenv("HOME");
+
+  if (home == nullptr || *home == '\0')
+    return;
+
+  CPPUNIT_ASSERT_EQUAL(resolve_path(home), resolve_path("~"));
+  CPPUNIT_ASSERT_THROW(resolve_path("~root/somewhere"), torrent::input_error);
+}
+
+void
+TestCommandPath::test_missing_path_throws() {
+  CPPUNIT_ASSERT_THROW(resolve_path_or_throw(""), torrent::input_error);
+  CPPUNIT_ASSERT_THROW(resolve_path_or_throw(m_temp_dir + "/does_not_exist"), torrent::input_error);
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", resolve_path_or_throw(m_temp_dir + "/link"));
+}
+
+void
+TestCommandPath::test_missing_path_is_empty() {
+  CPPUNIT_ASSERT_EQUAL(std::string(), resolve_path(""));
+  CPPUNIT_ASSERT_EQUAL(std::string(), resolve_path(m_temp_dir + "/does_not_exist"));
+  CPPUNIT_ASSERT_EQUAL(std::string(), resolve_path(m_temp_dir + "/does_not_exist/below"));
+
+  // A dangling symlink does not name an existing path either.
+  CPPUNIT_ASSERT_EQUAL(0, symlink((m_temp_dir + "/gone").c_str(), (m_temp_dir + "/dangling").c_str()));
+  CPPUNIT_ASSERT_EQUAL(std::string(), resolve_path(m_temp_dir + "/dangling"));
+  unlink((m_temp_dir + "/dangling").c_str());
+}
+
+void
+TestCommandPath::test_commands() {
+  torrent::initialize_main_thread();
+  torrent::initialize();
+
+  if (control == nullptr)
+    control = new Control;
+
+  if (!rpc::commands.has("directory.default.realpath.or_empty"))
+    initialize_command_local();
+
+  rpc::commands.call_command("directory.default.set", m_temp_dir + "/link");
+
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/link", rpc::commands.call_command("directory.default", torrent::Object()).as_string());
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", rpc::commands.call_command("directory.default.realpath.or_empty", torrent::Object()).as_string());
+  CPPUNIT_ASSERT_EQUAL(m_temp_dir + "/data", rpc::commands.call_command("directory.default.realpath.or_throw", torrent::Object()).as_string());
+
+  // A directory that has not been created yet resolves to nothing, and the
+  // or_throw variant reports it instead.
+  rpc::commands.call_command("directory.default.set", m_temp_dir + "/missing");
+
+  CPPUNIT_ASSERT_EQUAL(std::string(), rpc::commands.call_command("directory.default.realpath.or_empty", torrent::Object()).as_string());
+  CPPUNIT_ASSERT_THROW(rpc::commands.call_command("directory.default.realpath.or_throw", torrent::Object()), torrent::input_error);
+
+  torrent::cleanup();
+}

test/src/test_command_path.h

@@ -0,0 +1,30 @@
+#include "test/helpers/test_fixture.h"
+
+#include <string>
+
+class TestCommandPath : public test_fixture {
+  CPPUNIT_TEST_SUITE(TestCommandPath);
+
+  CPPUNIT_TEST(test_resolves_symlink);
+  CPPUNIT_TEST(test_removes_relative_components);
+  CPPUNIT_TEST(test_expands_tilde);
+  CPPUNIT_TEST(test_missing_path_is_empty);
+  CPPUNIT_TEST(test_missing_path_throws);
+  CPPUNIT_TEST(test_commands);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void setUp();
+  void tearDown();
+
+  void test_resolves_symlink();
+  void test_removes_relative_components();
+  void test_expands_tilde();
+  void test_missing_path_is_empty();
+  void test_missing_path_throws();
+  void test_commands();
+
+private:
+  std::string m_temp_dir;
+};