types: add overflow truncate when convert str to float (pingcap#5130)

Clenken · Nov 22, 2017 · 9921f41 · 9921f41
1 parent 8892bdf
commit 9921f41
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Showing 3 changed files with 32 additions and 0 deletions.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -3017,6 +3017,21 @@ func (s *testIntegrationSuite) TestIssues(c *C) {
 	tk.MustExec("insert into tb(v) (select v from tb);")
 	r = tk.MustQuery(`SELECT * FROM tb;`)
 	r.Check(testkit.Rows("1 hello", "2 hello"))
+
+	// for issue #5111
+	tk.MustExec(`drop table if exists t`)
+	tk.MustExec("create table t(c varchar(32));")
+	tk.MustExec("insert into t values('1e649'),('-1e649');")
+	r = tk.MustQuery(`SELECT * FROM t where c < 1;`)
+	r.Check(testkit.Rows("-1e649"))
+	tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|",
+		"Warning|1292|Truncated incorrect DOUBLE value: '1e649'",
+		"Warning|1292|Truncated incorrect DOUBLE value: '-1e649'"))
+	r = tk.MustQuery(`SELECT * FROM t where c > 1;`)
+	r.Check(testkit.Rows("1e649"))
+	tk.MustQuery("show warnings").Check(testutil.RowsWithSep("|",
+		"Warning|1292|Truncated incorrect DOUBLE value: '1e649'",
+		"Warning|1292|Truncated incorrect DOUBLE value: '-1e649'"))
 }
 
 func newStoreWithBootstrap() (kv.Storage, *domain.Domain, error) {

diff --git a/types/convert.go b/types/convert.go
@@ -291,6 +291,17 @@ func StrToFloat(sc *stmtctx.StatementContext, str string) (float64, error) {
 	validStr, err := getValidFloatPrefix(sc, str)
 	f, err1 := strconv.ParseFloat(validStr, 64)
 	if err1 != nil {
+		if err2, ok := err1.(*strconv.NumError); ok {
+			// value will truncate to MAX/MIN if out of range.
+			if err2.Err == strconv.ErrRange {
+				err1 = sc.HandleTruncate(ErrTruncatedWrongVal.GenByArgs("DOUBLE", str))
+				if math.IsInf(f, 1) {
+					f = math.MaxFloat64
+				} else if math.IsInf(f, -1) {
+					f = -math.MaxFloat64
+				}
+			}
+		}
 		return f, errors.Trace(err1)
 	}
 	return f, errors.Trace(err)

diff --git a/types/convert_test.go b/types/convert_test.go
@@ -448,6 +448,12 @@ func (s *testTypeConvertSuite) TestStrToNum(c *C) {
 	testStrToFloat(c, "11.xx", 11.0, false, nil)
 	testStrToFloat(c, "11.xx", 11.0, true, ErrTruncated)
 	testStrToFloat(c, "xx.11", 0.0, false, nil)
+
+	// for issue #5111
+	testStrToFloat(c, "1e649", math.MaxFloat64, true, ErrTruncatedWrongVal)
+	testStrToFloat(c, "1e649", math.MaxFloat64, false, nil)
+	testStrToFloat(c, "-1e649", -math.MaxFloat64, true, ErrTruncatedWrongVal)
+	testStrToFloat(c, "-1e649", -math.MaxFloat64, false, nil)
 }
 
 func (s *testTypeConvertSuite) TestFieldTypeToStr(c *C) {