chore: backport cosmos#13063 from cosmos/cosmos-sdk #323

types/context.go

@@ -262,11 +262,18 @@ func (c Context) TransientStore(key 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
 }
 
 // ContextKey defines a type alias for a stdlib Context key.

types/context_test.go

@@ -42,13 +42,18 @@ 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))
 
 	write()
 
 	s.Require().Equal(v2, store.Get(k2))
+	s.Require().Len(ctx.EventManager().Events(), 2)
 }
 
 func (s *contextTestSuite) TestLogContext() {

x/gov/abci.go

@@ -77,12 +77,6 @@ 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 {