Merge pull request #3648 from sysown/v2.3.2_3646_3647

Port to v2.3.2 of PRs #3646 and #3647

Author: renecannao

lib/MySQL_Thread.cpp

@@ -2543,7 +2543,10 @@ void MySQL_Threads_Handler::update_client_host_cache(struct sockaddr* client_soc
 	if (error) {
 		pthread_mutex_lock(&mutex_client_host_cache);
 		// If the cache is full, find the oldest entry on it, and update/remove it.
-		if (client_host_cache.size() >= static_cast<size_t>(mysql_thread___client_host_cache_size)) {
+		if (
+			mysql_thread___client_host_cache_size &&
+			client_host_cache.size() >= static_cast<size_t>(mysql_thread___client_host_cache_size)
+		) {
 			auto older_elem = std::min_element(
 				client_host_cache.begin(),
 				client_host_cache.end(),
@@ -2553,8 +2556,10 @@ void MySQL_Threads_Handler::update_client_host_cache(struct sockaddr* client_soc
 					return f_entry.second.updated_at < s_entry.second.updated_at;
 				}
 			);
-			if (older_elem->first != client_addr) {
-				client_host_cache.erase(older_elem);
+			if (older_elem != client_host_cache.end()) {
+				if (older_elem->first != client_addr) {
+					client_host_cache.erase(older_elem);
+				}
 			}
 		}
 
@@ -3711,7 +3716,9 @@ void MySQL_Thread::process_all_sessions() {
 			if (sess_time/1000 > (unsigned long long)mysql_thread___connect_timeout_client) {
 				proxy_warning("Closing not established client connection %s:%d after %llums\n",sess->client_myds->addr.addr,sess->client_myds->addr.port, sess_time/1000);
 				sess->healthy = 0;
-				GloMTH->update_client_host_cache(sess->client_myds->client_addr, true);
+				if (mysql_thread___client_host_cache_size) {
+					GloMTH->update_client_host_cache(sess->client_myds->client_addr, true);
+				}
 			}
 		}
 		if (maintenance_loop) {

lib/mysql_connection.cpp

@@ -2293,17 +2293,18 @@ bool MySQL_Connection::IsKeepMultiplexEnabledVariables(char *query_digest_text)
 	}
 	//filter @@session. and @@
 	char *match=NULL;
+	char* last_pos=NULL;
+	const int at_session_offset = strlen("@@session.");
+	const int double_at_offset = strlen("@@");
 	while (query_digest_text_filter_select && (match = strcasestr(query_digest_text_filter_select,"@@session."))) {
-		*match = '\0';
-		strcat(query_digest_text_filter_select, match+strlen("@@session."));
+		memmove(match, match + at_session_offset, strlen(match) - at_session_offset);
+		last_pos = match + strlen(match) - at_session_offset;
+		*last_pos = '\0';
 	}
 	while (query_digest_text_filter_select && (match = strcasestr(query_digest_text_filter_select,"@@"))) {
-		*match = '\0';
-		if (strlen(query_digest_text_filter_select) == 0) {
-			memcpy(query_digest_text_filter_select, match, strlen("@@"));
-		} else {
-			strcat(query_digest_text_filter_select, match+strlen("@@"));
-		}
+		memmove(match, match + double_at_offset, strlen(match) - double_at_offset);
+		last_pos = match + strlen(match) - double_at_offset;
+		*last_pos = '\0';
 	}
 
 	std::vector<char*>query_digest_text_filter_select_v;

test/tap/tests/client_host_err/create_netns_n.sh

@@ -1,4 +1,9 @@
 #!/bin/bash
+
+# NOTE: This script is currently unused, but it's left here because it's useful
+# for creating network namespaces in a easy way. It could be of use for future
+# testing.
+
 if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root"
    exit 1

test/tap/tests/client_host_err/delete_netns_n.sh

@@ -1,4 +1,9 @@
 #!/bin/bash
+
+# NOTE: This script is currently unused, but it's left here because it's useful
+# for deleting network namespaces in a easy way. It could be of use for future
+# testing.
+
 if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root"
    exit 1