core+legacy: fix display of non-divisible OMNI amounts

core/src/apps/wallet/sign_tx/omni.py

@@ -2,7 +2,12 @@ from ustruct import unpack
 
 from trezor.utils import format_amount
 
-currencies = {1: "OMNI", 2: "tOMNI", 3: "MAID", 31: "USDT"}
+currencies = {
+    1: ("OMNI", True),
+    2: ("tOMNI", True),
+    3: ("MAID", False),
+    31: ("USDT", True),
+}
 
 
 def is_valid(data: bytes) -> bool:
@@ -15,9 +20,10 @@ def parse(data: bytes) -> bool:
     tx_version, tx_type = unpack(">HH", data[4:8])
     if tx_version == 0 and tx_type == 0 and len(data) == 20:  # OMNI simple send
         currency, amount = unpack(">IQ", data[8:20])
+        suffix, divisible = currencies.get(currency, ("UNKN", False))
         return "Simple send of %s %s" % (
-            format_amount(amount, 8),
-            currencies.get(currency, "UNKN"),
+            format_amount(amount, 8 if divisible else 0),
+            suffix,
         )
     else:
         # unknown OMNI transaction

legacy/firmware/layout2.c

@@ -361,25 +361,30 @@ void layoutConfirmOmni(const uint8_t *data, uint32_t size) {
     desc = _("Simple send of ");
     REVERSE32(*(const uint32_t *)(data + 8), currency);
     const char *suffix = " UNKN";
+    bool divisible = false;
     switch (currency) {
       case 1:
         suffix = " OMNI";
+        divisible = true;
         break;
       case 2:
         suffix = " tOMNI";
+        divisible = true;
         break;
       case 3:
         suffix = " MAID";
+        divisible = false;
         break;
       case 31:
         suffix = " USDT";
+        divisible = true;
         break;
     }
     uint64_t amount_be, amount;
     memcpy(&amount_be, data + 12, sizeof(uint64_t));
     REVERSE64(amount_be, amount);
-    bn_format_uint64(amount, NULL, suffix, BITCOIN_DIVISIBILITY, 0, false,
-                     str_out, sizeof(str_out));
+    bn_format_uint64(amount, NULL, suffix, divisible ? BITCOIN_DIVISIBILITY : 0,
+                     0, false, str_out, sizeof(str_out));
   } else {
     desc = _("Unknown transaction");
     str_out[0] = 0;