diff options
Diffstat (limited to 'py')
| -rw-r--r-- | py/objstringio.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/py/objstringio.c b/py/objstringio.c index 046d325806..cb8003bcdd 100644 --- a/py/objstringio.c +++ b/py/objstringio.c @@ -125,8 +125,19 @@ STATIC mp_uint_t stringio_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg, ref = o->vstr->len; break; } - o->pos = ref + s->offset; - s->offset = o->pos; + mp_uint_t new_pos = ref + s->offset; + if (s->offset < 0) { + if (new_pos > ref) { + // Negative offset from SEEK_CUR or SEEK_END went past 0. + // CPython sets position to 0, POSIX returns an EINVAL error + new_pos = 0; + } + } else if (new_pos < ref) { + // positive offset went beyond the limit of mp_uint_t + *errcode = MP_EINVAL; // replace with MP_EOVERFLOW when defined + return MP_STREAM_ERROR; + } + s->offset = o->pos = new_pos; return 0; } case MP_STREAM_FLUSH: |