f_rename return value; add a test for rename dir inside itself

Author: dhalbert

extmod/vfs_fat.c

@@ -234,8 +234,6 @@ STATIC mp_obj_t fat_vfs_rename(mp_obj_t vfs_in, mp_obj_t path_in, mp_obj_t path_
     }
     if (res == FR_OK) {
         return mp_const_none;
-    } else if (res == FR_NO_PATH) {
-        mp_raise_OSError(MP_EINVAL);
     } else {
         mp_raise_OSError_fresult(res);
     }

lib/oofatfs/ff.c

@@ -4828,7 +4828,7 @@ FRESULT f_rename (
         strlen(path_new) > strlen(path_old) &&
         path_new[strlen(path_old)] == '/' &&
         strncmp(path_old, path_new, strlen(path_old)) == 0) {
-        return FR_NO_PATH;
+        return FR_INVALID_NAME;
     }
 
     res = find_volume(fs, FA_WRITE);    /* Get logical drive of the old object */

tests/extmod/vfs_fat_fileio2.py

@@ -70,6 +70,11 @@ def ioctl(self, op, arg):
 except OSError as e:
     print(e.errno == uerrno.ENOENT)
 
+try:
+    vfs.rename("foo_dir", "foo_dir/inside_itself")
+except OSError as e:
+    print(e.errno == uerrno.EINVAL)
+
 # file in dir
 with open("foo_dir/file-in-dir.txt", "w+t") as f:
     f.write("data in file")

tests/extmod/vfs_fat_fileio2.py.exp

@@ -1,6 +1,7 @@
 True
 True
 True
+True
 b'data in file'
 True
 [('sub_file.txt', 32768, 0, 11), ('file.txt', 32768, 0, 12)]