py/modstruct: In struct.pack, stop converting if there are no args left.

This patch makes a repeat counter behave the same as repeating the
typecode, when there are not enough args.  For example:
struct.pack('2I', 1) now behave the same as struct.pack('II', 1).
This commit is contained in:
Damien George 2017-09-01 10:10:51 +10:00
parent b349479a49
commit 793d826d9d
3 changed files with 6 additions and 1 deletions

View File

@ -206,7 +206,8 @@ STATIC void struct_pack_into_internal(mp_obj_t fmt_in, byte *p, byte* end_p, siz
memset(p + to_copy, 0, sz - to_copy);
p += sz;
} else {
while (sz--) {
// If we run out of args then we just finish; CPython would raise struct.error
while (sz-- && i < n_args) {
mp_binary_set_val(fmt_type, *fmt, args[i++], &p);
}
}

View File

@ -18,6 +18,9 @@ s = struct.pack("<O", o)
o2 = struct.unpack("<O", s)
print(o is o2[0])
# pack can accept less arguments than required for the format spec
print(struct.pack('<2I', 1))
# pack and unpack pointer to a string
# This requires uctypes to get the address of the string and instead of
# putting this in a dedicated test that can be skipped we simply pass

View File

@ -1 +1,2 @@
True
b'\x01\x00\x00\x00\x00\x00\x00\x00'