Bug #31077699: NORMAL USER CAN CREATE VIEW/PROC/TRIG WITH

DEFINER=USER_WITH_SYSTEM_USER_PRIV
RB#24132

The fetch of the ACL map for the current user was done based on the
login user and not the authenticated user. This caused artificially
created execution contexts that lack the login user being set to find the
wrong ACL map.
Fixed by using the privileged user instead.

sql/auth/sql_security_ctx.cc

@@ -389,26 +389,29 @@ void Security_context::checkout_access_maps(void) {
   if (m_acl_map != nullptr) {
     DBUG_PRINT(
         "info",
-        ("(checkout) Security_context for %s@%s returns Acl_map to cache. "
+        ("(checkout) Security_context for %.*s@%.*s returns Acl_map to cache. "
          "Map reference count= %u",
-         m_user.c_ptr(), m_host.c_ptr(), m_acl_map->reference_count()));
+         (int)m_priv_user_length, m_priv_user, (int)m_priv_host_length,
+         m_priv_host, m_acl_map->reference_count()));
     get_global_acl_cache()->return_acl_map(m_acl_map);
     m_acl_map = nullptr;
   }
 
   if (m_active_roles.size() == 0) return;
   ++m_map_checkout_count;
   Auth_id_ref uid;
-  uid.first.str = this->m_user.ptr();
-  uid.first.length = this->m_user.length();
-  uid.second.str = this->m_host_or_ip.ptr();
-  uid.second.length = this->m_host_or_ip.length();
+  uid.first.str = this->m_priv_user;
+  uid.first.length = this->m_priv_user_length;
+  uid.second.str = this->m_priv_host;
+  uid.second.length = this->m_priv_host_length;
   m_acl_map =
       get_global_acl_cache()->checkout_acl_map(this, uid, m_active_roles);
   if (m_acl_map != nullptr) {
-    DBUG_PRINT("info", ("Roles are active and global access for %s@%s is set to"
-                        " %lu",
-                        user().str, host_or_ip().str, m_acl_map->global_acl()));
+    DBUG_PRINT("info",
+               ("Roles are active and global access for %.*s@%.*s is set to"
+                " %lu",
+                (int)m_priv_user_length, m_priv_user, (int)m_priv_host_length,
+                m_priv_host, m_acl_map->global_acl()));
     set_master_access(m_acl_map->global_acl(), m_acl_map->restrictions());
   } else {
     set_master_access(0);