tests: add chdir in elua to prevent incorrect file accesses

Elua is testing API that tries to read files by path, prevent
unintentional reads from current working directory by changing
that directory.

src/tests/elua/elua_lib.c

@@ -4,6 +4,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include <Eina.h>
 #include <Elua.h>
@@ -28,6 +29,11 @@ EFL_START_TEST(elua_api)
     st = elua_state_new("test");
     fail_if(!st);
 
+    /* elua APIs here try accessing files by relative path,
+     * prevent any unintentional file accesses in cwd
+     */
+    fail_if(chdir(TESTS_SRC_DIR));
+
     /* test env vars */
     setenv("ELUA_CORE_DIR", "foo", 1);
     setenv("ELUA_MODULES_DIR", "bar", 1);