Bug#32651203: MYSQL_MIGRATE_KEYRING --ONLINE-MIGRATION CRASH

Description: Error handling needed improvements when insufficient
             details are provided to execute migration utility.

Fix: Update Keyring_migration class to handle connection
     errors better.

RB: 26222

Author: harinvadodaria

client/migrate_keyring/components.cc

@@ -181,13 +181,9 @@ Destination_keyring_services::~Destination_keyring_services() {
 Keyring_migrate::Keyring_migrate(Source_keyring_services &src,
                                  Destination_keyring_services &dst,
                                  bool online_migration)
-    : src_(src),
-      dst_(dst),
-      iterator_(nullptr),
-      mysql_connection_(online_migration),
-      ok_(false),
-      maximum_size_(16384) {
+    : src_(src), dst_(dst), mysql_connection_(online_migration) {
   if (!src_.ok() || !dst_.ok()) return;
+  if (online_migration && !mysql_connection_.ok()) return;
   if (lock_source_keyring() == false) {
     log_error << "Failed to lock source keyring" << std::endl;
     return;
@@ -202,12 +198,14 @@ Keyring_migrate::Keyring_migrate(Source_keyring_services &src,
 
 bool Keyring_migrate::lock_source_keyring() {
   if (Options::s_online_migration == false) return true;
+  if (!mysql_connection_.ok()) return false;
   std::string lock_statement("SET GLOBAL KEYRING_OPERATIONS=0");
   return mysql_connection_.execute(lock_statement);
 }
 
 bool Keyring_migrate::unlock_source_keyring() {
-  if (Options::s_online_migration == false) return true;
+  if (Options::s_online_migration == false || !mysql_connection_.ok())
+    return true;
   std::string unlock_statement("SET GLOBAL KEYRING_OPERATIONS=1");
   return mysql_connection_.execute(unlock_statement);
 }

client/migrate_keyring/components.h

@@ -137,10 +137,10 @@ class Keyring_migrate final {
  private:
   Source_keyring_services &src_;
   Destination_keyring_services &dst_;
-  my_h_keyring_keys_metadata_iterator iterator_;
+  my_h_keyring_keys_metadata_iterator iterator_{nullptr};
   options::Mysql_connection mysql_connection_;
-  bool ok_;
-  const size_t maximum_size_;
+  bool ok_{false};
+  const size_t maximum_size_{16384};
 };
 
 }  // namespace components

client/migrate_keyring/options.cc

@@ -329,8 +329,8 @@ Mysql_connection::Mysql_connection(bool connect) : ok_(false), mysql(nullptr) {
                           Options::s_password, NullS, Options::s_port,
                           Options::s_socket, CLIENT_REMEMBER_OPTIONS)) {
     mysql->reconnect = true;
-    log_error << "Failed to connect to server at " << Options::s_hostname
-              << ": " << mysql_error(mysql) << std::endl;
+    log_error << "Failed to connect to server. Received error: "
+              << mysql_error(mysql) << std::endl;
     return;
   }
   log_info << "Successfully connected to MySQL server" << std::endl;
@@ -350,7 +350,7 @@ Mysql_connection::~Mysql_connection() {
 
 bool Mysql_connection::execute(std::string command) {
   if (!ok_) {
-    log_error << " Connection to MySQL server is not initialized." << std::endl;
+    log_error << "Connection to MySQL server is not initialized." << std::endl;
     return false;
   }
   if (mysql_real_query(mysql, command.c_str(), command.length())) {