diff --git a/router/tests/component/test_bootstrap.cc b/router/tests/component/test_bootstrap.cc
index ed09865d8916..3c20eb116301 100644
--- a/router/tests/component/test_bootstrap.cc
+++ b/router/tests/component/test_bootstrap.cc
@@ -687,8 +687,8 @@ TEST_F(RouterBootstrapTest, BootstrapFailWhenServerResponseExceedsReadTimeout) {
       "-d", bootstrap_dir.name(), "--connect-timeout=1", "--read-timeout=1"};
 
   bootstrap_failover(mock_servers, router_options, EXIT_FAILURE,
-                     {"Error: Error executing MySQL query: Lost connection to "
-                      "MySQL server during query \\(2013\\)"});
+                     {"Error: Error executing MySQL query: Read timeout is "
+                      "reached \\(2066\\)"});
 }
 
 class RouterAccountHostTest : public CommonBootstrapTest {};
diff --git a/sql/mdl.cc b/sql/mdl.cc
index de9e3e10af8c..ce9c93590583 100644
--- a/sql/mdl.cc
+++ b/sql/mdl.cc
@@ -1468,7 +1468,8 @@ MDL_context::MDL_context()
       m_force_dml_deadlock_weight(false),
       m_waiting_for(NULL),
       m_pins(NULL),
-      m_rand_state(UINT_MAX32) {
+      m_rand_state(UINT_MAX32),
+      m_ignore_owner_thd(false) {
   mysql_prlock_init(key_MDL_context_LOCK_waiting_for, &m_LOCK_waiting_for);
 }
 
@@ -3350,7 +3351,8 @@ void MDL_lock::object_lock_notify_conflicting_locks(MDL_context *ctx,
     if (conflicting_ticket->get_ctx() != ctx &&
         (conflicting_ticket->get_type() == MDL_SHARED ||
          conflicting_ticket->get_type() == MDL_SHARED_HIGH_PRIO) &&
-        conflicting_ticket->get_ctx()->get_owner()->get_thd() != nullptr) {
+        (conflicting_ticket->get_ctx()->get_owner()->get_thd() != nullptr ||
+         ctx->get_ignore_owner_thd())) {
       MDL_context *conflicting_ctx = conflicting_ticket->get_ctx();
 
       /*
@@ -3524,16 +3526,18 @@ bool MDL_context::acquire_lock_nsec(MDL_request *mdl_request,
   */
   enum_mdl_type kill_conflicting_locks_lower_than = MDL_INTENTION_EXCLUSIVE;
   bool kill_conflicting_connections_after_timeout_and_retry = false;
-  if ((thd->variables.high_priority_ddl ||
-       (thd->slave_thread && slave_high_priority_ddl)) &&
-      ticket->get_type() >= MDL_SHARED_NO_WRITE) {
-    kill_conflicting_connections_after_timeout_and_retry = true;
-    /* Use MDL_SHARED_NO_WRITE to kill "lock tables read" connection */
-    kill_conflicting_locks_lower_than = MDL_SHARED_NO_WRITE;
-  }
-  if (thd->variables.kill_conflicting_connections) {
-    kill_conflicting_connections_after_timeout_and_retry = true;
-    kill_conflicting_locks_lower_than = MDL_TYPE_END;
+  if (thd != nullptr) {
+    if ((thd->variables.high_priority_ddl ||
+         (thd->slave_thread && slave_high_priority_ddl)) &&
+        ticket->get_type() >= MDL_SHARED_NO_WRITE) {
+      kill_conflicting_connections_after_timeout_and_retry = true;
+      /* Use MDL_SHARED_NO_WRITE to kill "lock tables read" connection */
+      kill_conflicting_locks_lower_than = MDL_SHARED_NO_WRITE;
+    }
+    if (thd->variables.kill_conflicting_connections) {
+      kill_conflicting_connections_after_timeout_and_retry = true;
+      kill_conflicting_locks_lower_than = MDL_TYPE_END;
+    }
   }
   /* do not set status on timeout if we are going to retry */
   bool set_status_on_timeout =
diff --git a/sql/mdl.h b/sql/mdl.h
index 930af28c590d..8a1349982ca8 100644
--- a/sql/mdl.h
+++ b/sql/mdl.h
@@ -1657,6 +1657,14 @@ class MDL_context {
   */
   uint m_rand_state;
 
+  /**
+    MDL_lock::object_lock_notify_conflicting_locks() checks THD of
+    conflicting lock on nullptr value and doesn't call the virtual
+    method MDL_context_owner::notify_shared_lock() in case condition
+    satisfied. This field allows unit tests to work with THD set to nullptr.
+  */
+  bool m_ignore_owner_thd;
+
  private:
   MDL_ticket *find_ticket(MDL_request *mdl_req, enum_mdl_duration *duration);
   void release_locks_stored_before(enum_mdl_duration duration,
@@ -1698,6 +1706,10 @@ class MDL_context {
   }
   void lock_deadlock_victim() { mysql_prlock_rdlock(&m_LOCK_waiting_for); }
   void unlock_deadlock_victim() { mysql_prlock_unlock(&m_LOCK_waiting_for); }
+  void set_ignore_owner_thd(bool ignore_owner_thd) {
+    m_ignore_owner_thd = ignore_owner_thd;
+  }
+  bool get_ignore_owner_thd() { return m_ignore_owner_thd; }
 
  private:
   MDL_context(const MDL_context &rhs);      /* not implemented */
diff --git a/unittest/gunit/mdl-t.cc b/unittest/gunit/mdl-t.cc
index f6e1bf4341b8..db3f10ac9949 100644
--- a/unittest/gunit/mdl-t.cc
+++ b/unittest/gunit/mdl-t.cc
@@ -112,6 +112,7 @@ class MDLTest : public ::testing::Test, public Test_MDL_context_owner {
     max_write_lock_count = ULONG_MAX;
     mdl_init();
     m_mdl_context.init(this);
+    m_mdl_context.set_ignore_owner_thd(true);
     EXPECT_FALSE(m_mdl_context.has_locks());
     m_charset = system_charset_info;
     system_charset_info = &my_charset_utf8_bin;
@@ -2181,6 +2182,7 @@ TEST_F(MDLTest, NotifyScenarios) {
   /* Acquire S lock which will be granted using "fast path". */
   mdl_thread1.enable_release_on_notify();
   mdl_thread1.start();
+  mdl_thread1.get_mdl_context().set_ignore_owner_thd(true);
   first_shared_grabbed.wait_for_notification();
 
   /*
@@ -2195,6 +2197,7 @@ TEST_F(MDLTest, NotifyScenarios) {
     should be successfully granted after that.
   */
   mdl_thread2.start();
+  mdl_thread2.get_mdl_context().set_ignore_owner_thd(true);
   first_shared_released.wait_for_notification();
   first_exclusive_grabbed.wait_for_notification();
 
@@ -2222,6 +2225,7 @@ TEST_F(MDLTest, NotifyScenarios) {
   mdl_thread3.enable_release_on_notify();
   /* Acquire S lock which will be granted using "fast path". */
   mdl_thread3.start();
+  mdl_thread3.get_mdl_context().set_ignore_owner_thd(true);
   second_shared_grabbed.wait_for_notification();
 
   /*
@@ -2230,6 +2234,7 @@ TEST_F(MDLTest, NotifyScenarios) {
     should be successfully granted after that.
   */
   mdl_thread4.start();
+  mdl_thread4.get_mdl_context().set_ignore_owner_thd(true);
   second_shared_released.wait_for_notification();
   second_exclusive_grabbed.wait_for_notification();
 
diff --git a/unittest/gunit/mysys_pathfuncs-t.cc b/unittest/gunit/mysys_pathfuncs-t.cc
index c473ab9724b9..4511a9271706 100644
--- a/unittest/gunit/mysys_pathfuncs-t.cc
+++ b/unittest/gunit/mysys_pathfuncs-t.cc
@@ -152,7 +152,7 @@ TEST(Mysys, CreateTempFile) {
   File fileno = create_temp_file(dst, "/tmp", prefix, 42, UNLINK_FILE, 0);
   EXPECT_GE(fileno, 0);
   my_close(fileno, 0);
-  EXPECT_THAT(dst, MatchesRegex("/tmp/[a]+fd=[0-9]+"));
+  EXPECT_THAT(dst, MatchesRegex("/tmp/[a]+[a-z0-9=]+"));
   aset(dst, 0xaa);
 
   char *env_tmpdir = getenv("TMPDIR");
diff --git a/unittest/gunit/parsertest.h b/unittest/gunit/parsertest.h
index 0b677dc8e71b..215e47bdbcfd 100644
--- a/unittest/gunit/parsertest.h
+++ b/unittest/gunit/parsertest.h
@@ -75,7 +75,7 @@ class ParserTest : public ::testing::Test {
           static_cast<char *>(my_malloc(PSI_NOT_INSTRUMENTED, 3, MYF(0)));
       sprintf(db, "db");
       LEX_CSTRING db_lex_cstr = {db, strlen(db)};
-      thd()->reset_db(db_lex_cstr);
+      thd()->reset_db(db_lex_cstr, /* lock_held_skip_metadata */ true);
     }
 
     lex_start(thd());
diff --git a/unittest/gunit/test_mdl_context_owner.h b/unittest/gunit/test_mdl_context_owner.h
index 415516472f24..6319d2fe74ae 100644
--- a/unittest/gunit/test_mdl_context_owner.h
+++ b/unittest/gunit/test_mdl_context_owner.h
@@ -37,15 +37,7 @@ class Test_MDL_context_owner : public MDL_context_owner {
 
   virtual int is_killed() const final { return 0; }
   virtual bool is_connected() { return true; }
-  virtual THD *get_thd() {
-    /*
-      MDL_lock::object_lock_notify_conflicting_locks() checks THD of
-      conflicting lock on nullptr value and doesn't call the virtual
-      method MDL_context_owner::notify_shared_lock() in case condition
-      satisfied. To workaround it return the value 1 casted to THD*.
-    */
-    return (THD *)1;
-  }
+  virtual THD *get_thd() { return nullptr; }
 
   virtual bool notify_hton_pre_acquire_exclusive(const MDL_key *, bool *) {
     return false;