executor: runWithSystemSession also copy snapshot status (#54989) (#…

…55028)

close #54964

pkg/executor/set.go

@@ -316,20 +316,24 @@ func (e *SetExecutor) loadSnapshotInfoSchemaIfNeeded(name string, snapshotTS uin
 	if name != variable.TiDBSnapshot && name != variable.TiDBTxnReadTS {
 		return nil
 	}
-	vars := e.Ctx().GetSessionVars()
+	return loadSnapshotInfoSchemaIfNeeded(e.Ctx(), snapshotTS)
+}
+
+func loadSnapshotInfoSchemaIfNeeded(sctx sessionctx.Context, snapshotTS uint64) error {
+	vars := sctx.GetSessionVars()
 	if snapshotTS == 0 {
 		vars.SnapshotInfoschema = nil
 		return nil
 	}
 	logutil.BgLogger().Info("load snapshot info schema",
 		zap.Uint64("conn", vars.ConnectionID),
 		zap.Uint64("SnapshotTS", snapshotTS))
-	dom := domain.GetDomain(e.Ctx())
+	dom := domain.GetDomain(sctx)
 	snapInfo, err := dom.GetSnapshotInfoSchema(snapshotTS)
 	if err != nil {
 		return err
 	}
 
-	vars.SnapshotInfoschema = temptable.AttachLocalTemporaryTableInfoSchema(e.Ctx(), snapInfo)
+	vars.SnapshotInfoschema = temptable.AttachLocalTemporaryTableInfoSchema(sctx, snapInfo)
 	return nil
 }

pkg/executor/show.go

@@ -2398,6 +2398,10 @@ func runWithSystemSession(ctx context.Context, sctx sessionctx.Context, fn func(
 		return err
 	}
 	defer b.ReleaseSysSession(ctx, sysCtx)
+
+	if err = loadSnapshotInfoSchemaIfNeeded(sysCtx, sctx.GetSessionVars().SnapshotTS); err != nil {
+		return err
+	}
 	// `fn` may use KV transaction, so initialize the txn here
 	if err = sessiontxn.NewTxn(ctx, sysCtx); err != nil {
 		return err