fix(textual): error if a formatted coin contains a comma (#19265)

Co-authored-by: Aleksandr Bezobchuk <[email protected]>

x/tx/CHANGELOG.md

@@ -31,6 +31,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+### Bug Fixes
+
+* [#19265](https://github.com/cosmos/cosmos-sdk/pull/19265) Reject denoms that contain a comma.
+
 ### Improvements
 
 * [#18857](https://github.com/cosmos/cosmos-sdk/pull/18857) Moved `FormatCoins` from `core/coins` to this package under `signing/textual`.

x/tx/signing/textual/coins.go

@@ -284,6 +284,12 @@ func FormatCoins(coins []*basev1beta1.Coin, metadata []*bankv1beta1.Metadata) (s
 		if err != nil {
 			return "", err
 		}
+
+		// If a coin contains a comma, return an error given that the output
+		// could be misinterpreted by the user as 2 different coins.
+		if strings.Contains(formatted[i], ",") {
+			return "", fmt.Errorf("coin %s contains a comma", formatted[i])
+		}
 	}
 
 	if len(coins) == 0 {

x/tx/signing/textual/internal/testdata/coin.json

@@ -327,5 +327,10 @@
   {"text":"", "error": true},
   {"text":"1COSM", "error": true},
   {"text":"1  COSM", "error": true},
-  {"text":" 1  COSM", "error": true}
+  {"text":" 1  COSM", "error": true},
+  {
+    "proto": {"amount": "10000000", "denom": "point, 222222 point"},
+    "metadata": {"display": "POINT", "base": "point", "denom_units": [{"denom": "point", "exponent": 0}, {"denom": "POINT", "exponent": 0}]},
+    "error": true
+  }
 ]