expression, executor: allow insert strings with overflowed trailing spaces (#20987)

executor/insert_test.go

@@ -1268,3 +1268,19 @@ func (s *testSuite9) TestIssue20768(c *C) {
 	tk.MustQuery("select /*+ inl_merge_join(t1) */ * from t1 join t2 on t1.a = t2.a").Check(testkit.Rows("0 0"))
 	tk.MustQuery("select /*+ merge_join(t1) */ * from t1 join t2 on t1.a = t2.a").Check(testkit.Rows("0 0"))
 }
+
+func (s *testSuite9) TestIssue10402(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("create table vctt (v varchar(4), c char(4))")
+	tk.MustExec("insert into vctt values ('ab  ', 'ab   ')")
+	tk.MustQuery("select * from vctt").Check(testkit.Rows("ab   ab"))
+	tk.MustExec("delete from vctt")
+	tk.Se.GetSessionVars().StmtCtx.SetWarnings(nil)
+	tk.MustExec("insert into vctt values ('ab\\n\\n\\n', 'ab\\n\\n\\n'), ('ab\\t\\t\\t', 'ab\\t\\t\\t'), ('ab    ', 'ab    '), ('ab\\r\\r\\r', 'ab\\r\\r\\r')")
+	c.Check(tk.Se.GetSessionVars().StmtCtx.WarningCount(), Equals, uint16(4))
+	warns := tk.Se.GetSessionVars().StmtCtx.GetWarnings()
+	c.Check(fmt.Sprintf("%v", warns), Equals, "[{Warning [types:1265]Data truncated, field len 4, data len 5} {Warning [types:1265]Data truncated, field len 4, data len 5} {Warning [types:1265]Data truncated, field len 4, data len 6} {Warning [types:1265]Data truncated, field len 4, data len 5}]")
+	tk.MustQuery("select * from vctt").Check(testkit.Rows("ab\n\n ab\n\n", "ab\t\t ab\t\t", "ab   ab", "ab\r\r ab\r\r"))
+	tk.MustQuery("select length(v), length(c) from vctt").Check(testkit.Rows("4 4", "4 4", "4 2", "4 4"))
+}

types/datum.go

@@ -952,10 +952,14 @@ func (d *Datum) convertToString(sc *stmtctx.StatementContext, target *FieldType)
 func ProduceStrWithSpecifiedTp(s string, tp *FieldType, sc *stmtctx.StatementContext, padZero bool) (_ string, err error) {
 	flen, chs := tp.Flen, tp.Charset
 	if flen >= 0 {
+		// overflowed stores the part of the string that is out of the length contraint, it is later checked to see if the
+		// overflowed part is all whitespaces
+		var overflowed string
+		var characterLen int
 		// Flen is the rune length, not binary length, for UTF8 charset, we need to calculate the
 		// rune count and truncate to Flen runes if it is too long.
 		if chs == charset.CharsetUTF8 || chs == charset.CharsetUTF8MB4 {
-			characterLen := utf8.RuneCountInString(s)
+			characterLen = utf8.RuneCountInString(s)
 			if characterLen > flen {
 				// 1. If len(s) is 0 and flen is 0, truncateLen will be 0, don't truncate s.
 				//    CREATE TABLE t (a char(0));
@@ -972,13 +976,27 @@ func ProduceStrWithSpecifiedTp(s string, tp *FieldType, sc *stmtctx.StatementCon
 					}
 					runeCount++
 				}
-				err = ErrDataTooLong.GenWithStack("Data Too Long, field len %d, data len %d", flen, characterLen)
+				overflowed = s[truncateLen:]
 				s = truncateStr(s, truncateLen)
 			}
 		} else if len(s) > flen {
-			err = ErrDataTooLong.GenWithStack("Data Too Long, field len %d, data len %d", flen, len(s))
+			characterLen = len(s)
+			overflowed = s[flen:]
 			s = truncateStr(s, flen)
-		} else if tp.Tp == mysql.TypeString && IsBinaryStr(tp) && len(s) < flen && padZero {
+		}
+
+		if len(overflowed) != 0 {
+			trimed := strings.TrimRight(overflowed, " \t\n\r")
+			if len(trimed) == 0 && !IsBinaryStr(tp) && IsTypeChar(tp.Tp) {
+				if tp.Tp == mysql.TypeVarchar {
+					sc.AppendWarning(ErrTruncated.GenWithStack("Data truncated, field len %d, data len %d", flen, characterLen))
+				}
+			} else {
+				err = ErrDataTooLong.GenWithStack("Data Too Long, field len %d, data len %d", flen, characterLen)
+			}
+		}
+
+		if tp.Tp == mysql.TypeString && IsBinaryStr(tp) && len(s) < flen && padZero {
 			padding := make([]byte, flen-len(s))
 			s = string(append([]byte(s), padding...))
 		}