[MDEV-20304] Inconsistency in to-integer conversion in DOUBLE UNSIGNED vs DECIMAL UNSIGNED - Jira

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Type: Bug
Status: Open (View Workflow)
Priority: Major
Resolution: Unresolved
Affects Version/s: 5.5(EOL), 10.0(EOL), 10.1(EOL), 10.2(EOL), 10.3(EOL), 10.4(EOL)
Fix Version/s: 10.3(EOL)
Component/s: Data types
Labels:
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CREATE OR REPLACE TABLE t1 (a BIGINT UNSIGNED, b DOUBLE UNSIGNED, c DECIMAL(30,0) UNSIGNED);

INSERT INTO t1 VALUES(18446744073709551615,18446744073709551615,18446744073709551615);

SELECT a, b, c, a << 0, b << 0, c << 0 FROM t1\G

MariaDB [test]> SELECT a, b, c, a << 0, b << 0, c << 0 FROM t1\G

*************************** 1. row ***************************

     a: 18446744073709551615

     b: 1.8446744073709552e19

     c: 18446744073709551615

a << 0: 18446744073709551615

b << 0: 9223372036854775807

c << 0: 18446744073709551615

1 row in set, 1 warning (0.00 sec)

Notice, the result for `b << 0` is probably wrong.

This happens because Field_double::val_int() does not take into accoung the UNSIGNED flag, while Field_new_decimal does.

Note, this problem is repeatable with any function calling val_int(). The left shift operation is used only for demonstration purposes.