Removed faulty check for 'character_set_connection' in 'character_set_connection' test and updated comments #3460

test/tap/tests/set_character_set-t.cpp

@@ -23,8 +23,11 @@
  *
  *   For checking that this variables has changed or keep their values properly.
  *
- *   NOTE: For making sure that all the operations are being performed in the same backend
- *   connection, test starts a transaction. For more context see #3460.
+ *   NOTE: After "SET CHARACTER SET 'latin1'" has been issued, no checks are performed for
+ *   'character_set_connection' since, due to multiplexing and ProxySQL explicitely forgetting
+ *   the value for 'character_set_connection' and 'collation_connection' (for more context
+ *   see MySQL_Variables::client_set_value),the value for it is **unknown** and depends entirely
+ *   of the backend connection selected. For more context see #3460.
  */
 
 #include <cstdlib>
@@ -45,7 +48,7 @@ int main(int argc, char** argv) {
 	if(cl.getEnv())
 		return exit_status();
 
-	plan(12);
+	plan(11);
 	diag("Testing SET CHARACTER SET");
 
 	MYSQL* mysql = mysql_init(NULL);
@@ -82,16 +85,6 @@ int main(int argc, char** argv) {
 		return exit_status();
 	}
 
-	/**
-	 * NOTE: A transaction is started to ensure that all the following operations are
-	 * performed over the same backend connection. See #3640 for more context.
-	 */
-	if (mysql_query(mysql, "BEGIN")) {
-		fprintf(stderr, "File %s, line %d, Error: %s\n",
-				__FILE__, __LINE__, mysql_error(mysql));
-		return exit_status();
-	}
-
 	if (mysql_query(mysql, "set names 'utf8'")) {
 		fprintf(stderr, "SET NAMES 'utf8': Error: %s\n",
 				mysql_error(mysql));
@@ -131,11 +124,16 @@ int main(int argc, char** argv) {
 	show_variable(mysql, var_charset_database, var_value);
 	ok(var_value.compare("utf8") == 0, "Database character set is not changed. Actual %s", var_value.c_str()); // ok_6
 
-	show_variable(mysql, var_charset_connection, var_value);
-	ok(var_value.compare(db_charset_value) == 0, "Connection character set same as database charset. Actual %s", var_value.c_str()); // ok_7
+	/*
+	 * NOTE: This check was disabled because trying to check 'character_set_connection' after issuing 'SET CHARACTER SET',
+	 * when multiplexing is enabled is invalid, since the value is unknown. Check file top for more details.
+	 *
+	 * show_variable(mysql, var_charset_connection, var_value);
+	 * ok(var_value.compare(db_charset_value) == 0, "Connection character set same as database charset. Actual %s", var_value.c_str()); // ok_
+	 */
 
 	show_variable(mysql, var_charset_results, var_value);
-	ok(var_value.compare("latin1") == 0, "Results character set is changed. Actual %s", var_value.c_str()); // ok_8
+	ok(var_value.compare("latin1") == 0, "Results character set is changed. Actual %s", var_value.c_str()); // ok_7
 
 	if (mysql_query(mysql, "set names latin1")) {
 		fprintf(stderr, "SET NAMES : Error: %s\n",
@@ -144,16 +142,16 @@ int main(int argc, char** argv) {
 	}
 
 	show_variable(mysql, var_charset_client, var_value);
-	ok(var_value.compare("latin1") == 0, "Client character set is correct. Actual %s", var_value.c_str()); // ok_9
+	ok(var_value.compare("latin1") == 0, "Client character set is correct. Actual %s", var_value.c_str()); // ok_8
 
 	show_variable(mysql, var_charset_connection, var_value);
-	ok(var_value.compare("latin1") == 0, "Set names changed connection character set. Actual %s", var_value.c_str()); // ok_10
+	ok(var_value.compare("latin1") == 0, "Set names changed connection character set. Actual %s", var_value.c_str()); // ok_9
 
 	show_variable(mysql, var_charset_results, var_value);
-	ok(var_value.compare("latin1") == 0, "Results character set is correct. Actual %s", var_value.c_str()); // ok_11
+	ok(var_value.compare("latin1") == 0, "Results character set is correct. Actual %s", var_value.c_str()); // ok_10
 
 	show_variable(mysql, var_charset_database, var_value);
-	ok(var_value.compare("utf8") == 0, "Database character set is not changed by set names. Actual %s", var_value.c_str()); // ok_12
+	ok(var_value.compare("utf8") == 0, "Database character set is not changed by set names. Actual %s", var_value.c_str()); // ok_11
 
 	mysql_close(mysql);