Merge pull request #4850 from sysown/v2.7-4841

Fix issue #4841

Author: renecannao

lib/mysql_connection.cpp

@@ -774,18 +774,33 @@ void MySQL_Connection::connect_start_SetCharset() {
 		csname = mysql_variables.client_get_value(myds->sess, SQL_CHARACTER_SET);
 	}
 
-	const MARIADB_CHARSET_INFO * c = NULL;
+	MARIADB_CHARSET_INFO * c = NULL;
 	if (csname)
-		c = proxysql_find_charset_nr(atoi(csname));
+		c = (MARIADB_CHARSET_INFO *)proxysql_find_charset_nr(atoi(csname));
 	else
-		c = proxysql_find_charset_name(mysql_thread___default_variables[SQL_CHARACTER_SET]);
+		c = (MARIADB_CHARSET_INFO *)proxysql_find_charset_name(mysql_thread___default_variables[SQL_CHARACTER_SET]);
 
 	if (!c) {
 		// LCOV_EXCL_START
 		proxy_error("Not existing charset number %s\n", mysql_thread___default_variables[SQL_CHARACTER_SET]);
 		assert(0);
 		// LCOV_EXCL_STOP
 	}
+
+	if (c->nr > 255) {
+		const char *csname_default = c->csname;
+		c = NULL;
+		c = (MARIADB_CHARSET_INFO *)proxysql_find_charset_name(csname_default);
+		if (!c) {
+			// LCOV_EXCL_START
+			proxy_error("Not existing charset number %s\n", mysql_thread___default_variables[SQL_CHARACTER_SET]);
+			assert(0);
+			// LCOV_EXCL_STOP
+		}
+	}
+
+
+
 	{
 		/* We are connecting to backend setting charset in mysql_options.
 		 * Client already has sent us a character set and client connection variables have been already set.

test/tap/tap/utils.cpp

@@ -243,13 +243,15 @@ int mysql_query_t__(MYSQL* mysql, const char* query, const char* f, int ln, cons
 	return mysql_query(mysql, query);
 }
 
-int show_variable(MYSQL *mysql, const string& var_name, string& var_value) {
-	char query[128];
+int show_variable(MYSQL *mysql, const string& var_name, string& var_value, bool new_connection) {
 
-	snprintf(query, sizeof(query),"show variables like '%s'", var_name.c_str());
-	if (mysql_query(mysql, query)) {
+	std::string query = "show variables ";
+	query += (new_connection == true ? "/* create_new_connection=1 */ " : "");
+	query += " like '" + var_name + "'";
+
+	if (mysql_query(mysql, query.c_str())) {
 		fprintf(stderr, "Failed to execute query [%s] : no %d, %s\n",
-				query, mysql_errno(mysql), mysql_error(mysql));
+				query.c_str(), mysql_errno(mysql), mysql_error(mysql));
 		return exit_status();
 	}
 

test/tap/tap/utils.h

@@ -119,7 +119,7 @@ int mysql_query_t__(MYSQL* mysql, const char* query, const char* f, int ln, cons
 		} \
 	} while(0)
 
-int show_variable(MYSQL *mysql, const std::string& var_name, std::string& var_value);
+int show_variable(MYSQL *mysql, const std::string& var_name, std::string& var_value, bool new_connection=false);
 int show_admin_global_variable(MYSQL *mysql, const std::string& var_name, std::string& var_value);
 int set_admin_global_variable(MYSQL *mysql, const std::string& var_name, const std::string& var_value);
 int get_server_version(MYSQL *mysql, std::string& version);

test/tap/tests/test_utf8mb4_as_ci-4841-t.cpp

@@ -0,0 +1,57 @@
+/**
+ * @file test_utf8mb4_as_ci-4841-t.cpp
+ * @brief This test checks the use of collation 305 (utf8mb4_as_ci) .
+ * @details The test performs a 'SET NAMES' query to set utf8mb4_as_ci collation, then run a query
+ * on backend to verify the collation.
+ */
+
+#include <cstdlib>
+#include <cstdio>
+#include <cstring>
+#include <unistd.h>
+
+#include <string>
+#include "mysql.h"
+
+#include "tap.h"
+#include "command_line.h"
+#include "utils.h"
+
+int main(int argc, char** argv) {
+	CommandLine cl;
+
+	if(cl.getEnv())
+		return exit_status();
+
+	plan(1);
+	diag("Testing SET NAMES utf8mb4 COLLATE utf8mb4_0900_as_ci");
+
+	MYSQL* mysql = mysql_init(NULL);
+	if (!mysql)
+		return exit_status();
+
+	if (!mysql_real_connect(mysql, cl.host, cl.username, cl.password, NULL, cl.port, NULL, 0)) {
+		fprintf(stderr, "Failed to connect to database: Error: %s\n",
+				mysql_error(mysql));
+		return exit_status();
+	}
+
+	char * query = (char *)"SET NAMES utf8mb4 COLLATE utf8mb4_0900_as_ci";
+	if (mysql_query(mysql, query)) {
+		fprintf(stderr, "%s: Error: %s\n",
+				query,
+				mysql_error(mysql));
+		return exit_status();
+	}
+
+	std::string var_collation_connection = "collation_connection";
+	std::string var_value;
+
+	show_variable(mysql, var_collation_connection, var_value, true);
+	ok(var_value.compare("utf8mb4_0900_as_ci") == 0, "collation_connection , Expected utf8mb4_0900_as_ci . Actual %s", var_value.c_str()); // ok_1
+
+	mysql_close(mysql);
+
+	return exit_status();
+}
+