tests: Introduce functions to change directories

This introduces torture_get_current_working_dir() and
torture_change_dir() to allow changing directories in tests.

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

tests/unittests/torture_push_pop_dir.c

@@ -0,0 +1,78 @@
+#include "config.h"
+
+#include "torture.h"
+#define LIBSSH_STATIC
+
+const char template[] = "temp_dir_XXXXXX";
+
+static int setup(void **state)
+{
+    char *temp_dir = NULL;
+
+    temp_dir = torture_make_temp_dir(template);
+    assert_non_null(temp_dir);
+
+    *state = (void *)temp_dir;
+
+    return 0;
+}
+
+static int teardown(void **state)
+{
+    char *temp_dir = *((char **)state);
+
+    torture_rmdirs((const char *)temp_dir);
+
+    free(temp_dir);
+
+    return 0;
+}
+
+static void torture_back_and_forth(void **state)
+{
+    char *temp_dir = *((char **)state);
+    char *cwd = NULL;
+    char *after_change = NULL;
+    char *after_changing_back = NULL;
+    int rc = 0;
+
+    cwd = torture_get_current_working_dir();
+    assert_non_null(cwd);
+
+    printf("Current dir: %s\n", cwd);
+
+    rc = torture_change_dir(temp_dir);
+    assert_int_equal(rc, 0);
+
+    after_change = torture_get_current_working_dir();
+    assert_non_null(after_change);
+
+    printf("Current dir after change: %s\n", after_change);
+
+    rc = torture_change_dir(cwd);
+    assert_int_equal(rc, 0);
+
+    after_changing_back = torture_get_current_working_dir();
+    assert_non_null(after_changing_back);
+
+    printf("Back to dir: %s\n", after_changing_back);
+
+    SAFE_FREE(cwd);
+    SAFE_FREE(after_change);
+    SAFE_FREE(after_changing_back);
+}
+
+int torture_run_tests(void)
+{
+    int rc;
+    struct CMUnitTest tests[] = {
+        cmocka_unit_test_setup_teardown(torture_back_and_forth,
+                                        setup, teardown),
+    };
+
+    torture_filter_tests(tests);
+    rc = cmocka_run_group_tests(tests, NULL, NULL);
+
+    return rc;
+}
+