Problem: memiavl snapshot rewrite could rollback state

Solution:
- wait for async commit to finish to make sure catching up to latest state.

CHANGELOG.md

@@ -33,6 +33,7 @@
 - [#1087](https://github.com/crypto-org-chain/cronos/pull/1087) memiavl fix LastCommitID when memiavl db not loaded.
 - [#1088](https://github.com/crypto-org-chain/cronos/pull/1088) memiavl fix empty value in write-ahead-log replaying.
 - [#1102](https://github.com/crypto-org-chain/cronos/pull/1102) avoid duplicate cache events emitted from ibc and gravity hook.
+- [#]() Fix memiavl snapshot switching
 
 ### Features
 

memiavl/db.go

@@ -341,6 +341,11 @@ func (db *DB) checkBackgroundSnapshotRewrite() error {
 			return fmt.Errorf("background snapshot rewriting failed: %w", result.err)
 		}
 
+		// wait for pending wal writings to finish, to make sure catching up to latest state
+		if err := db.WaitAsyncCommit(); err != nil {
+			return fmt.Errorf("wait async commit failed: %w", err)
+		}
+
 		// catchup the remaining wal
 		if err := result.mtree.CatchupWAL(db.wal, 0); err != nil {
 			return fmt.Errorf("catchup failed: %w", err)