From d6db24b2d43a4f7d68547bd5fc5212e636a860f2 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Tue, 12 Oct 2021 12:47:54 +0200
Subject: [PATCH] fix: null guard for tx fee amounts (backport #10327) (#10342)

* fix: null guard for tx fee amounts (#10327)

## Description

It is possible to submit a TX with a fees object containing a Coin with a nil amount. This results in a rather cryptic redacted panic response when the basic validation checks fee Coins for negative amounts.

This PR adds an additional check for nil to provide a friendlier error message.

---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [x] provided a link to the relevant issue or specification (note: No issue exists)
- [x] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [x] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing) (note: First PR against the SDK so please comment with what needs to be done)
- [x] added a changelog entry to `CHANGELOG.md`
- [x] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [x] reviewed "Files changed" and left comments if necessary
- [x] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

(cherry picked from commit 96e162b8a3939c7999c0c12c39d196698594306c)

# Conflicts:
#	CHANGELOG.md

* solve conflicts

* move sections

Co-authored-by: Alex Megalokonomos <alex.megalokonomos@tendermint.com>
Co-authored-by: marbar3778 <marbar3778@yahoo.com>
---
 CHANGELOG.md       | 1 +
 types/coin.go      | 2 +-
 types/coin_test.go | 1 +
 types/tx/types.go  | 2 +-
 4 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d999ef21db13..cc9a32b78b5a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Improvements
 
 * [\#10262](https://github.com/cosmos/cosmos-sdk/pull/10262) Remove unnecessary logging in `x/feegrant` simulation.
+* [\#10327](https://github.com/cosmos/cosmos-sdk/pull/10327) Add null guard for possible nil `Amount` in tx fee `Coins`
 
 ### Bug Fixes
 
diff --git a/types/coin.go b/types/coin.go
index f6627c4c3a81..fd81cb58203a 100644
--- a/types/coin.go
+++ b/types/coin.go
@@ -181,7 +181,7 @@ func (coin Coin) IsNegative() bool {
 
 // IsNil returns true if the coin amount is nil and false otherwise.
 func (coin Coin) IsNil() bool {
-	return coin.Amount.BigInt() == nil
+	return coin.Amount.i == nil
 }
 
 //-----------------------------------------------------------------------------
diff --git a/types/coin_test.go b/types/coin_test.go
index 0c746ffb6206..2f9873ab42a8 100644
--- a/types/coin_test.go
+++ b/types/coin_test.go
@@ -1319,6 +1319,7 @@ func (s *coinTestSuite) TestCoinsIsAnyNil() {
 	s.Require().True(sdk.Coins{twoAtom, nilAtom, fiveAtom, threeEth}.IsAnyNil())
 	s.Require().True(sdk.Coins{nilAtom, twoAtom, fiveAtom, threeEth}.IsAnyNil())
 	s.Require().False(sdk.Coins{twoAtom, fiveAtom, threeEth}.IsAnyNil())
+
 }
 
 func (s *coinTestSuite) TestMarshalJSONCoins() {
diff --git a/types/tx/types.go b/types/tx/types.go
index b8a61946538c..ac2f01e404ca 100644
--- a/types/tx/types.go
+++ b/types/tx/types.go
@@ -66,7 +66,7 @@ func (t *Tx) ValidateBasic() error {
 	}
 
 	if fee.Amount.IsAnyNil() {
-		return errorsmod.Wrapf(
+		return sdkerrors.Wrapf(
 			sdkerrors.ErrInsufficientFee,
 			"invalid fee provided: null",
 		)