Forbid force slave visit in transaction context

Author: lazio579

plugins/proxy/proxy-plugin.c

@@ -1170,9 +1170,13 @@ process_query_or_stmt_prepare(network_mysqld_con *con, proxy_plugin_con_t *st,
     }
 
     /* forbid force write on slave */
-    if ((context->rw_flag & CF_FORCE_SLAVE) && (context->rw_flag & CF_WRITE)) {
+    if ((context->rw_flag & CF_FORCE_SLAVE) && ((context->rw_flag & CF_WRITE) || con->is_in_transaction)) {
         g_message("%s Comment usage error. SQL: %s", G_STRLOC, con->orig_sql->str);
-        network_mysqld_con_send_error(con->client, C("Force write on read-only slave"));
+        if (con->is_in_transaction) {
+            network_mysqld_con_send_error(con->client, C("Force transaction on read-only slave"));
+        } else {
+            network_mysqld_con_send_error(con->client, C("Force write on read-only slave"));
+        }
         *disp_flag = PROXY_SEND_RESULT;
         return 0;
     }

plugins/shard/shard-plugin.c

@@ -666,9 +666,13 @@ proxy_parse_query(network_mysqld_con *con)
                 return PROXY_SEND_RESULT;
             }
             /* forbid force write on slave */
-            if ((context->rw_flag & CF_FORCE_SLAVE) && (context->rw_flag & CF_WRITE)) {
+            if ((context->rw_flag & CF_FORCE_SLAVE) && ((context->rw_flag & CF_WRITE) || con->is_in_transaction)) {
                 g_message("%s Comment usage error. SQL: %s", G_STRLOC, con->orig_sql->str);
-                network_mysqld_con_send_error(con->client, C("Force write on read-only slave"));
+                if (con->is_in_transaction) {
+                    network_mysqld_con_send_error(con->client, C("Force transaction on read-only slave"));
+                } else {
+                    network_mysqld_con_send_error(con->client, C("Force write on read-only slave"));
+                }
                 return PROXY_SEND_RESULT;
             }