types: compare nil by type assertion in datum value setting (#19225)
types: compare nil by type assertion in datum value setting (#19225)


c4pt0r/tidb,coocood/tidb,kyle-wang/tidb,c4pt0r/tidb,pingcap/tidb,ngaut/tidb,XuHuaiyu/tidb,c4pt0r/tidb,c4pt0r/tidb,ngaut/tidb,kyle-wang/tidb,ngaut/tidb,c4pt0r/tidb,EvilMcJerkface/tidb,coocood/tidb,EvilMcJerkface/tidb,kyle-wang/tidb,ngaut/tidb,kyle-wang/tidb,pingcap/tidb,pingcap/tidb,c4pt0r/tidb,kyle-wang/tidb,XuHuaiyu/tidb,pingcap/tidb,kyle-wang/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb