MDEV-39199: Fix incorrect LEFT JOIN result with INT UNIQUE key and DOUBLE literal

mysql-test/main/mdev_39199.result

@@ -0,0 +1,17 @@
+#
+# MDEV-39196: LEFT JOIN wrong result with INT UNIQUE key vs DOUBLE literal
+#
+CREATE DATABASE IF NOT EXISTS logic_bug_focus;
+USE logic_bug_focus;
+CREATE TABLE t0(c0 INT UNIQUE);
+CREATE TABLE t2(c0 INT);
+INSERT INTO t0(c0) VALUES (0);
+INSERT INTO t2(c0) VALUES (1);
+# Should return 1, NULL
+SELECT t2.c0 AS t2_c0, t0.c0 AS t0_c0
+FROM t2 LEFT JOIN t0 ON t0.c0 = 0.1;
+t2_c0	t0_c0
+1	NULL
+# Cleanup
+DROP TABLE t0, t2;
+DROP DATABASE logic_bug_focus;

mysql-test/main/mdev_39199.test

@@ -0,0 +1,21 @@
+--source include/have_innodb.inc
+
+--echo #
+--echo # MDEV-39196: LEFT JOIN wrong result with INT UNIQUE key vs DOUBLE literal
+--echo #
+
+CREATE DATABASE IF NOT EXISTS logic_bug_focus;
+USE logic_bug_focus;
+
+CREATE TABLE t0(c0 INT UNIQUE);
+CREATE TABLE t2(c0 INT);
+INSERT INTO t0(c0) VALUES (0);
+INSERT INTO t2(c0) VALUES (1);
+
+--echo # Should return 1, NULL
+SELECT t2.c0 AS t2_c0, t0.c0 AS t0_c0
+FROM t2 LEFT JOIN t0 ON t0.c0 = 0.1;
+
+--echo # Cleanup
+DROP TABLE t0, t2;
+DROP DATABASE logic_bug_focus;