From 9d7028d070f2971c4ba940512500bfe17ce855d4 Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Mon, 31 Oct 2022 23:18:26 +0100
Subject: [PATCH] feat: emit cached context events (backport #13063) (#13702)

---
 CHANGELOG.md                 |  4 ++++
 types/context.go             | 11 +++++++++--
 types/context_test.go        |  5 +++++
 x/gov/abci.go                |  6 ------
 x/group/keeper/msg_server.go |  8 +-------
 5 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5e2b0ba368f8..5d34c0e703d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,10 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/auth/tx) [#12474](https://github.com/cosmos/cosmos-sdk/pull/12474) Remove condition in GetTxsEvent that disallowed multiple equal signs, which would break event queries with base64 strings (i.e. query by signature).
 * (store) [#13530](https://github.com/cosmos/cosmos-sdk/pull/13530) Fix app-hash mismatch if upgrade migration commit is interrupted.
 
+## API Breaking Changes
+
+* (context) [#13063](https://github.com/cosmos/cosmos-sdk/pull/13063) Update `Context#CacheContext` to automatically emit all events on the parent context's `EventManager`.
+
 ## [v0.46.3](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.46.3) - 2022-10-20
 
 ATTENTION:
diff --git a/types/context.go b/types/context.go
index d4bca9cec645..8a050a1b0803 100644
--- a/types/context.go
+++ b/types/context.go
@@ -268,11 +268,18 @@ func (c Context) TransientStore(key storetypes.StoreKey) KVStore {
 
 // CacheContext returns a new Context with the multi-store cached and a new
 // EventManager. The cached context is written to the context when writeCache
-// is called.
+// is called. Note, events are automatically emitted on the parent context's
+// EventManager when the caller executes the write.
 func (c Context) CacheContext() (cc Context, writeCache func()) {
 	cms := c.MultiStore().CacheMultiStore()
 	cc = c.WithMultiStore(cms).WithEventManager(NewEventManager())
-	return cc, cms.Write
+
+	writeCache = func() {
+		c.EventManager().EmitEvents(cc.EventManager().Events())
+		cms.Write()
+	}
+
+	return cc, writeCache
 }
 
 var _ context.Context = Context{}
diff --git a/types/context_test.go b/types/context_test.go
index 95406f55c8a9..f5c7cadeb541 100644
--- a/types/context_test.go
+++ b/types/context_test.go
@@ -42,6 +42,10 @@ func (s *contextTestSuite) TestCacheContext() {
 	s.Require().Equal(v1, cstore.Get(k1))
 	s.Require().Nil(cstore.Get(k2))
 
+	// emit some events
+	cctx.EventManager().EmitEvent(types.NewEvent("foo", types.NewAttribute("key", "value")))
+	cctx.EventManager().EmitEvent(types.NewEvent("bar", types.NewAttribute("key", "value")))
+
 	cstore.Set(k2, v2)
 	s.Require().Equal(v2, cstore.Get(k2))
 	s.Require().Nil(store.Get(k2))
@@ -49,6 +53,7 @@ func (s *contextTestSuite) TestCacheContext() {
 	write()
 
 	s.Require().Equal(v2, store.Get(k2))
+	s.Require().Len(ctx.EventManager().Events(), 2)
 }
 
 func (s *contextTestSuite) TestLogContext() {
diff --git a/x/gov/abci.go b/x/gov/abci.go
index 9f97cba47b4d..cde12c34a80c 100644
--- a/x/gov/abci.go
+++ b/x/gov/abci.go
@@ -84,12 +84,6 @@ func EndBlocker(ctx sdk.Context, keeper keeper.Keeper) {
 				tagValue = types.AttributeValueProposalPassed
 				logMsg = "passed"
 
-				// The cached context is created with a new EventManager. However, since
-				// the proposal handler execution was successful, we want to track/keep
-				// any events emitted, so we re-emit to "merge" the events into the
-				// original Context's EventManager.
-				ctx.EventManager().EmitEvents(cacheCtx.EventManager().Events())
-
 				// write state to the underlying multi-store
 				writeCache()
 			} else {
diff --git a/x/group/keeper/msg_server.go b/x/group/keeper/msg_server.go
index fb1ab258901c..6f6cee539f93 100644
--- a/x/group/keeper/msg_server.go
+++ b/x/group/keeper/msg_server.go
@@ -754,19 +754,13 @@ func (k Keeper) Exec(goCtx context.Context, req *group.MsgExec) (*group.MsgExecR
 			return nil, err
 		}
 
-		results, err := k.doExecuteMsgs(cacheCtx, k.router, proposal, addr)
-		if err != nil {
+		if _, err := k.doExecuteMsgs(cacheCtx, k.router, proposal, addr); err != nil {
 			proposal.ExecutorResult = group.PROPOSAL_EXECUTOR_RESULT_FAILURE
 			logs = fmt.Sprintf("proposal execution failed on proposal %d, because of error %s", id, err.Error())
 			k.Logger(ctx).Info("proposal execution failed", "cause", err, "proposalID", id)
 		} else {
 			proposal.ExecutorResult = group.PROPOSAL_EXECUTOR_RESULT_SUCCESS
 			flush()
-
-			for _, res := range results {
-				// NOTE: The sdk msg handler creates a new EventManager, so events must be correctly propagated back to the current context
-				ctx.EventManager().EmitEvents(res.GetEvents())
-			}
 		}
 	}