Misc. small cleanups unrelated to any particular MDEV

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

sql/log.cc

@@ -7587,7 +7587,7 @@ MYSQL_BIN_LOG::queue_for_group_commit(group_commit_entry *orig_entry)
 
         Setting this flag may or may not be seen by the other thread, but we
         are safe in any case: The other thread will set queued_by_other under
-        its LOCK_wait_commit, and we will not check queued_by_other only after
+        its LOCK_wait_commit, and we will not check queued_by_other until after
         we have been woken up.
       */
       wfc->opaque_pointer= orig_entry;
@@ -7684,7 +7684,7 @@ MYSQL_BIN_LOG::queue_for_group_commit(group_commit_entry *orig_entry)
     is pointed to by `last` (we do not use NULL to terminate the list).
 
     As we process an entry, any waiters for that entry are added at the end of
-    the list, to be processed in subsequent iterations. The the entry is added
+    the list, to be processed in subsequent iterations. Then the entry is added
     to the group_commit_queue.  This continues until the list is exhausted,
     with all entries ever added eventually processed.
 

sql/sql_class.cc

@@ -7643,7 +7643,7 @@ wait_for_commit::wait_for_prior_commit2(THD *thd)
 {
   PSI_stage_info old_stage;
   wait_for_commit *loc_waitee;
-  bool backup_lock_released= 0;
+  bool backup_lock_released= false;
 
   /*
     Release MDL_BACKUP_COMMIT LOCK while waiting for other threads to commit
@@ -7653,7 +7653,7 @@ wait_for_commit::wait_for_prior_commit2(THD *thd)
   */
   if (thd->backup_commit_lock && thd->backup_commit_lock->ticket)
   {
-    backup_lock_released= 1;
+    backup_lock_released= true;
     thd->mdl_context.release_lock(thd->backup_commit_lock->ticket);
     thd->backup_commit_lock->ticket= 0;
   }
@@ -7706,14 +7706,14 @@ wait_for_commit::wait_for_prior_commit2(THD *thd)
     use within enter_cond/exit_cond.
   */
   DEBUG_SYNC(thd, "wait_for_prior_commit_killed");
-  if (backup_lock_released)
+  if (unlikely(backup_lock_released))
     thd->mdl_context.acquire_lock(thd->backup_commit_lock,
                                   thd->variables.lock_wait_timeout);
   return wakeup_error;
 
 end:
   thd->EXIT_COND(&old_stage);
-  if (backup_lock_released)
+  if (unlikely(backup_lock_released))
     thd->mdl_context.acquire_lock(thd->backup_commit_lock,
                                   thd->variables.lock_wait_timeout);
   return wakeup_error;