[Bug]: x/bank: query balances with --resolve-denom panics when metadata lacks display field

[arlai-mk]

Is there an existing issue for this?

• I have searched the existing issues

What happened?

The bank query balances command panics when used with --resolve-denom flag if any token's metadata lacks a display field. The panic occurs in sdk.NewCoin() during coin validation because an empty denom string is passed when metadata.Display is empty.

For example, querying metadata for factory/neutron10r39fueph9fq7a6lgswu4zdsg8t3gxlqgn9xk5/Governance on Neutron shows:

{
  "metadata": {
    "denom_units": [
      {
        "denom": "factory/neutron10r39fueph9fq7a6lgswu4zdsg8t3gxlqgn9xk5/Governance"
      }
    ],
    "base": "factory/neutron10r39fueph9fq7a6lgswu4zdsg8t3gxlqgn9xk5/Governance"
  }
}

The code at x/bank/keeper/grpc_query.go:68 uses metadata.Display without checking if it exists, passing an empty string to sdk.NewCoin(). This triggers a panic in the NewCoin function during coin.Validate() as empty denom strings are invalid.

Expected behavior:
When display field is missing from metadata, the query should fall back to using the base denom instead of attempting to create a coin with an empty denom.

Cosmos SDK Version

main

How to reproduce?

How to reproduce:

1. Find an account holding tokens whose metadata lacks a display field
2. Run bank balances query with --resolve-denom flag:

neutrond query bank balances neutron1qpqw3h7a2k9s0jkjtjfa8ghhes4jdevs89uljn --resolve-denom

Current output:

Error: rpc error: code = Unknown desc = invalid denom: : panic

Expected output: The query should complete successfully, showing balances with base denoms for tokens lacking display fields.