ethereum: don't show unrecognized ERC-20 tokens as sending message

firmware/ethereum.c

@@ -203,6 +203,10 @@ static void ethereumFormatAmount(const bignum256 *amnt, const TokenType *token,
 	bn_read_uint32(1000000000, &bn1e9);
 	const char *suffix = NULL;
 	int decimals = 18;
+	if (token == UnknownToken) {
+		strlcpy(buf, "Unrecognized Token", buflen);
+		return;
+	} else
 	if (token != NULL) {
 		suffix = token->ticker;
 		decimals = token->decimals;

firmware/ethereum_tokens.c

@@ -84,6 +84,8 @@ const TokenType tokens[TOKENS_COUNT] = {
 	{61, "\x08\x5f\xb4\xf2\x40\x31\xea\xed\xbc\x2b\x61\x1a\xa5\x28\xf2\x23\x43\xeb\x52\xdb", " BEC", 8},
 };
 
+const TokenType *UnknownToken = (const TokenType *)1;
+
 const TokenType *tokenByChainAddress(uint8_t chain_id, const uint8_t *address)
 {
 	if (!address) return 0;
@@ -92,5 +94,5 @@ const TokenType *tokenByChainAddress(uint8_t chain_id, const uint8_t *address)
 			return &(tokens[i]);
 		}
 	}
-	return 0;
+	return UnknownToken;
 }

firmware/ethereum_tokens.h

@@ -33,6 +33,8 @@ typedef struct {
 
 extern const TokenType tokens[TOKENS_COUNT];
 
+extern const TokenType *UnknownToken;
+
 const TokenType *tokenByChainAddress(uint8_t chain_id, const uint8_t *address);
 
 #endif