bech32 decoder looks for the first '1' as the HRP separator, not the last '1' as specified

Lines 95 to 99 in 60848c2

    
           *data_len = 0; 
        
           while (*data_len < input_len && input[(input_len - 1) - *data_len] != '1') { 
        
               ++(*data_len); 
        
           } 
        
           hrp_len = input_len - (1 + *data_len);

https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki#bech32 says that the last '1' in the string is the HRP separator. The reference code is inconsistent with that and with Bitcoin Core.

I don't think so; (*data_len) increments, but is used as a negative in the index to input: input[(input_len - 1) - *data_len], so it counts backwards.

There is also a unit test for an HRP that includes a "1", which both the C and C++ code pass.

You're right, sorry for the invalid report.

	*data_len = 0;
	while (data_len < input_len && input[(input_len - 1) - data_len] != '1') {
	++(*data_len);
	}
	hrp_len = input_len - (1 + *data_len);