Issue #2 - provisional resolution to RFC3339 date encoding

Fixes an issue where a GF(256) remainder used for reed-solomon error
correction bytes is a codeword short on return from division. This may
not be the final resolution to the wider issue.

Author: komone

src/qrcode_reedsolomon.erl

@@ -25,9 +25,14 @@ encode(Bin, Degree) when Degree > 0 ->
 	Data = binary_to_list(Bin),
 	Coeffs = gf256:monomial_product(Field, Data, 1, Degree),
 	{_Quotient, Remainder} = gf256:divide(Field, Coeffs, Generator),
-	ErrorCorrectionBytes = list_to_binary(Remainder),
+	Remainder0 = zero_pad(Degree, Remainder),
+	ErrorCorrectionBytes = list_to_binary(Remainder0),
 	<<ErrorCorrectionBytes/binary>>.
 
+zero_pad(Length, R) when length(R) < Length ->
+	zero_pad(Length, [0|R]);
+zero_pad(_, R) ->
+	R.
 %%
 bch_code(Byte, Poly) ->
 	MSB = msb(Poly),