expression: fix builtin function 'round' (pingcap#13985)

fatpa · Jan 15, 2020 · 7efe9bf · 7efe9bf
1 parent 1e9f908
commit 7efe9bf
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/expression/builtin_math_test.go b/expression/builtin_math_test.go
@@ -426,6 +426,8 @@ func (s *testEvaluatorSuite) TestRound(c *C) {
 		{[]interface{}{newDec("1.58"), 1}, newDec("1.6")},
 		{[]interface{}{newDec("23.298"), -1}, newDec("20")},
 		{[]interface{}{nil, 2}, nil},
+		{[]interface{}{1, -2012}, 0},
+		{[]interface{}{1, -201299999999999}, 0},
 	}
 
 	Dtbl := tblToDtbl(tbl)

diff --git a/types/helper.go b/types/helper.go
@@ -43,7 +43,11 @@ func Round(f float64, dec int) float64 {
 	if math.IsInf(tmp, 0) {
 		return f
 	}
-	return RoundFloat(tmp) / shift
+	result := RoundFloat(tmp) / shift
+	if math.IsNaN(result) {
+		return 0
+	}
+	return result
 }
 
 // Truncate truncates the argument f to dec decimal places.