ddl: add error check in ddlCtx.buildDescTableScan (pingcap#8726)

ddl/reorg.go

@@ -250,6 +250,10 @@ func (d *ddlCtx) buildDescTableScan(ctx context.Context, startTS uint64, tbl tab
 	builder.Request.Priority = kv.PriorityLow
 
 	kvReq, err := builder.Build()
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+
 	sctx := newContext(d.store)
 	result, err := distsql.Select(ctx, sctx, kvReq, getColumnsTypes(columns), statistics.NewQueryFeedback(0, nil, 0, false))
 	if err != nil {

executor/admin.go

@@ -114,6 +114,9 @@ func (e *CheckIndexRangeExec) Open(ctx context.Context) error {
 		SetKeepOrder(true).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
 		Build()
+	if err != nil {
+		return errors.Trace(err)
+	}
 
 	e.result, err = distsql.Select(ctx, e.ctx, kvReq, e.retFieldTypes, statistics.NewQueryFeedback(0, nil, 0, false))
 	if err != nil {
@@ -259,6 +262,9 @@ func (e *RecoverIndexExec) buildTableScan(ctx context.Context, txn kv.Transactio
 		SetKeepOrder(true).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
 		Build()
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
 
 	// Actually, with limitCnt, the match datas maybe only in one region, so let the concurrency to be 1,
 	// avoid unnecessary region scan.
@@ -621,6 +627,10 @@ func (e *CleanupIndexExec) buildIndexScan(ctx context.Context, txn kv.Transactio
 		SetKeepOrder(true).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
 		Build()
+	if err != nil {
+		return nil, errors.Trace(err)
+	}
+
 	kvReq.KeyRanges[0].StartKey = kv.Key(e.lastIdxKey).PrefixNext()
 	kvReq.Concurrency = 1
 	result, err := distsql.Select(ctx, e.ctx, kvReq, e.getIdxColTypes(), statistics.NewQueryFeedback(0, nil, 0, false))

executor/analyze.go

@@ -175,6 +175,9 @@ func (e *AnalyzeIndexExec) open() error {
 		SetKeepOrder(true).
 		SetConcurrency(e.concurrency).
 		Build()
+	if err != nil {
+		return errors.Trace(err)
+	}
 	ctx := context.TODO()
 	e.result, err = distsql.Analyze(ctx, e.ctx.GetClient(), kvReq, e.ctx.GetSessionVars().KVVars, e.ctx.GetSessionVars().InRestrictedSQL)
 	if err != nil {