fix: Use fixed length hex for pointer at FwdCapabilityKey (backport c…

…osmos#11737)

CHANGELOG.md

@@ -54,6 +54,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/mint) [#12384](https://github.com/cosmos/cosmos-sdk/pull/12384) Ensure `GoalBonded` must be positive when performing `x/mint` parameter validation.
 * (simapp) [#12437](https://github.com/cosmos/cosmos-sdk/pull/12437) fix the non-determinstic behavior in simulations caused by `GenTx` and check 
 empty coins slice before it is used to create `banktype.MsgSend`.
+* (x/capability) []() Use fixed length hex for pointer at FwdCapabilityKey.
 
 ## [v0.45.6](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.45.6) - 2022-06-28
 

x/capability/types/keys.go

@@ -39,7 +39,12 @@ func RevCapabilityKey(module, name string) []byte {
 // FwdCapabilityKey returns a forward lookup key for a given module and capability
 // reference.
 func FwdCapabilityKey(module string, cap *Capability) []byte {
-	return []byte(fmt.Sprintf("%s/fwd/%p", module, cap))
+	// truncate the key to fixed length, keep backward compatible on common architectures.
+	key := fmt.Sprintf("%#010p", cap)
+	if len(key) > 10 {
+		key = key[len(key)-10:]
+	}
+	return []byte(fmt.Sprintf("%s/fwd/0x%s", module, key))
 }
 
 // IndexToKey returns bytes to be used as a key for a given capability index.

x/capability/types/keys_test.go

@@ -16,7 +16,12 @@ func TestRevCapabilityKey(t *testing.T) {
 
 func TestFwdCapabilityKey(t *testing.T) {
 	cap := types.NewCapability(23)
-	expected := []byte(fmt.Sprintf("bank/fwd/%p", cap))
+	key := fmt.Sprintf("%#010p", cap)
+	if len(key) > 10 {
+		key = key[len(key)-10:]
+	}
+	require.Equal(t, 10, len(key))
+	expected := []byte(fmt.Sprintf("bank/fwd/0x%s", key))
 	require.Equal(t, expected, types.FwdCapabilityKey("bank", cap))
 }