#80 Set ERC20 decimals upon coin enable to avoid repetitive requests.

iguana/exchanges/LP_commands.c

@@ -616,6 +616,13 @@ version\n\
                         if (etomic_coin->inactive != 0) {
                             return(clonestr("{\"error\":\"Enable ETOMIC first to use ETH/ERC20!\"}"));
                         }
+
+                        if (ptr->decimals == 0 && strcmp(coin, "ETH") != 0) {
+                            ptr->decimals = getErc20DecimalsZeroOnError(ptr->etomic);
+                            if (ptr->decimals == 0) {
+                                return(clonestr("{\"error\":\"Could not get token decimals or token has zero decimals which is not supported!\"}"));
+                            }
+                        }
                     }
 #endif
                     if ( LP_conflicts_find(ptr) == 0 )

iguana/exchanges/etomicswap/etomiclib.cpp

@@ -636,6 +636,18 @@ uint8_t getErc20Decimals(char *tokenAddress)
     return decimals;
 }
 
+uint8_t getErc20DecimalsZeroOnError(char *tokenAddress)
+{
+    char* hexDecimals = ethCall(tokenAddress, "0x313ce567");
+    if (hexDecimals != NULL) {
+        auto decimals = (uint8_t) strtol(hexDecimals, NULL, 0);
+        free(hexDecimals);
+        return decimals;
+    } else {
+        return 0;
+    }
+}
+
 void uint8arrayToHex(char *dest, uint8_t *input, int len)
 {
     strcpy(dest, "0x");

iguana/exchanges/etomicswap/etomiclib.h

@@ -215,6 +215,7 @@ uint64_t estimate_erc20_gas(
 
 uint8_t compareAddresses(char *address1, char *address2);
 uint8_t isValidAddress(char *address);
+uint8_t getErc20DecimalsZeroOnError(char *tokenAddress);
 
 #ifdef __cplusplus
 }