From 8b9db66ddd0381706d22e4fabd731bf39103cad9 Mon Sep 17 00:00:00 2001
From: Serguey Zefiov <serguey.zefirov@mariadb.com>
Date: Mon, 10 Feb 2025 20:18:06 +0000
Subject: [PATCH] fix(MCOL-5889): Improper handle of DOUBLE result type with
 DECIMAL arguments

Sometimes server assigns DOUBLE type for arithmetic operations over
DECIMAL arguments. In this rare case width of result was incorrectly
adjusted and it triggered an assertion.

Now width of result gets adjusted only if result type is also DECIMAL.
---
 dbcon/mysql/ha_mcs_execplan.cpp               |  3 ++-
 .../MCOL-5889-double-is-not-decimal.result    | 25 +++++++++++++++++++
 .../MCOL-5889-double-is-not-decimal.test      | 24 ++++++++++++++++++
 tests/scripts/fullmtr.sh                      |  6 +++++
 4 files changed, 57 insertions(+), 1 deletion(-)
 create mode 100644 mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.result
 create mode 100644 mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.test

diff --git a/dbcon/mysql/ha_mcs_execplan.cpp b/dbcon/mysql/ha_mcs_execplan.cpp
index 6ec3990ce..a597155e6 100644
--- a/dbcon/mysql/ha_mcs_execplan.cpp
+++ b/dbcon/mysql/ha_mcs_execplan.cpp
@@ -4025,7 +4025,8 @@ ReturnedColumn* buildArithmeticColumnBody(Item_func* item, gp_walk_info& gwi, bo
     int32_t leftColWidth = leftColType.colWidth;
     int32_t rightColWidth = rightColType.colWidth;
 
-    if (leftColWidth == datatypes::MAXDECIMALWIDTH || rightColWidth == datatypes::MAXDECIMALWIDTH)
+    if ((leftColWidth == datatypes::MAXDECIMALWIDTH || rightColWidth == datatypes::MAXDECIMALWIDTH)
+        && datatypes::isDecimal(mysqlType.colDataType))
     {
       mysqlType.colWidth = datatypes::MAXDECIMALWIDTH;
 
diff --git a/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.result b/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.result
new file mode 100644
index 000000000..b8a31665c
--- /dev/null
+++ b/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.result
@@ -0,0 +1,25 @@
+DROP DATABASE IF EXISTS MCOL5889;
+CREATE DATABASE MCOL5889;
+USE MCOL5889;
+CREATE TABLE t1 (f1 DECIMAL, f2 BIGINT, f3 DOUBLE) ENGINE=columnstore;
+CREATE TABLE t2 (f1 DECIMAL, f2 INT, f3 DOUBLE) ENGINE=columnstore;
+INSERT INTO t1 VALUES (1, 2, 3), (2, 3, 4), (3, 4, 5);
+INSERT INTO t2 VALUES (4, 5, 6), (5, 6, 7), (6, 7, 8);
+SELECT f1, f2, f3, f2 * f3 FROM
+(
+SELECT f1, f2, AVG(f3) f3 FROM
+(
+SELECT f1, f2, f3 FROM t1
+UNION ALL
+SELECT f1, f2, f3 FROM t2
+) U
+GROUP BY f1
+) V;
+f1	f2	f3	f2 * f3
+1	2	3	6
+2	3	4	12
+3	4	5	20
+4	5	6	30
+5	6	7	42
+6	7	8	56
+DROP DATABASE MCOL5889;
diff --git a/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.test b/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.test
new file mode 100644
index 000000000..2786ac009
--- /dev/null
+++ b/mysql-test/columnstore/bugfixes/MCOL-5889-double-is-not-decimal.test
@@ -0,0 +1,24 @@
+--disable_warnings
+DROP DATABASE IF EXISTS MCOL5889;
+--enable_warnings
+CREATE DATABASE MCOL5889;
+USE MCOL5889;
+
+CREATE TABLE t1 (f1 DECIMAL, f2 BIGINT, f3 DOUBLE) ENGINE=columnstore;
+CREATE TABLE t2 (f1 DECIMAL, f2 INT, f3 DOUBLE) ENGINE=columnstore;
+INSERT INTO t1 VALUES (1, 2, 3), (2, 3, 4), (3, 4, 5);
+INSERT INTO t2 VALUES (4, 5, 6), (5, 6, 7), (6, 7, 8);
+
+--sorted_result
+SELECT f1, f2, f3, f2 * f3 FROM
+(
+  SELECT f1, f2, AVG(f3) f3 FROM
+  (
+    SELECT f1, f2, f3 FROM t1
+    UNION ALL
+    SELECT f1, f2, f3 FROM t2
+  ) U
+  GROUP BY f1
+) V;
+
+DROP DATABASE MCOL5889;
diff --git a/tests/scripts/fullmtr.sh b/tests/scripts/fullmtr.sh
index 8ed3f2133..470a03c9c 100644
--- a/tests/scripts/fullmtr.sh
+++ b/tests/scripts/fullmtr.sh
@@ -40,6 +40,12 @@ if (( $# == 2 )); then
     exit 1
 fi
 
+if (( $# == 1 )); then
+    run_suite $1
+    exit 1
+fi
+
+
 run_suite basic
 run_suite bugfixes
 run_suite setup