add a unit test - NOTE: this test fails

Author: MohamedM216

mysql-test/main/mysql_client_test-mysql-source-errors.result

@@ -0,0 +1,8 @@
+#
+# MDEV-36269: Improve error handling for SOURCE command
+# Test that SOURCE on an existent directory returns a clear error
+#
+#
+# Try to SOURCE the /client directory (should fail)
+#
+ERROR: Failed to read from '/home/mohammad/open-source/mariaDB/server/client': it is a directory, or memory allocation failed

mysql-test/main/mysql_client_test-mysql-source-errors.test

@@ -0,0 +1,11 @@
+--echo #
+--echo # MDEV-36269: Improve error handling for SOURCE command
+--echo # Test that SOURCE on an existent directory returns a clear error
+--echo #
+
+--echo #
+--echo # Try to SOURCE the /client directory (should fail)
+--echo #
+
+--error 1
+--exec $MYSQL -e "source /home/mohammad/open-source/mariaDB/server/client"