Add extra test cases to BIP173

Author: sipa

bip-0173.mediawiki

@@ -268,6 +268,16 @@ The following strings have a valid Bech32 checksum.
 * <tt>11qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqc8247j</tt>
 * <tt>split1checkupstagehandshakeupstreamerranterredcaperred2y9e3w</tt>
 
+The following strings have an invalid Bech32 checksum (with reason for invalidity):
+* 0x20 + <tt>1nwldj5</tt>: HRP character out of range
+* 0x7F + <tt>1axkwrx</tt>: HRP character out of range
+* <tt>an84characterslonghumanreadablepartthatcontainsthenumber1andtheexcludedcharactersbio1569pvx</tt>: overall max length exceeded
+* <tt>pzry9x0s0muk</tt>: No separator character
+* <tt>1pzry9x0s0muk</tt>: Empty HRP
+* <tt>x1b4n0q5v</tt>: Invalid data character
+* <tt>li1dgmt3</tt>: Too short checksum
+* <tt>de1lg7wt</tt> + 0xFF: Invalid character in checksum
+
 The following list gives valid segwit addresses and the scriptPubKey that they
 translate to in hex.
 * <tt>BC1QW508D6QEJXTDG4Y5R3ZARVARY0C5XW7KV8F3T4</tt>: <tt>0014751e76e8199196d454941c45d1b3a323f1433bd6</tt>
@@ -286,8 +296,9 @@ their invalidity.
 * <tt>bc10w508d6qejxtdg4y5r3zarvary0c5xw7kw508d6qejxtdg4y5r3zarvary0c5xw7kw5rljs90</tt>: Invalid program length
 * <tt>BC1QR508D6QEJXTDG4Y5R3ZARVARYV98GJ9P</tt>: Invalid program length for witness version 0 (per BIP141)
 * <tt>tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3q0sL5k7</tt>: Mixed case
-* <tt>tb1pw508d6qejxtdg4y5r3zarqfsj6c3</tt>: zero padding of more than 4 bits
+* <tt>bc1zw508d6qejxtdg4y5r3zarvaryvqyzf3du</tt>: zero padding of more than 4 bits
 * <tt>tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3pjxtptv</tt>: Non-zero padding in 8-to-5 conversion
+* <tt>bc1gmk9yu</tt>: Empty data section
 
 ===Checksum design===