MDEV-7962: Follow-up fix for 10.4

Replace wsrep_on() with trx_t::is_wsrep() where possible.

Also, rename some functions to member functions and
remove unused DBUG_EXECUTE_IF instrumentation:

trx_t::commit(): Renamed from trx_commit().

trx_t::commit_low(): Renamed from trx_commit_low().

trx_t::commit_in_memory(): Renamed from trx_commit_in_memory().

storage/innobase/handler/handler0alter.cc

@@ -7079,7 +7079,7 @@ prepare_inplace_alter_table_dict(
 			goto error_handling;
 		}
 
-		trx_commit(ctx->trx);
+		ctx->trx->commit();
 		trx_start_for_ddl(ctx->trx, op);
 
 		if (!ctx->new_table->fts
@@ -11101,7 +11101,7 @@ ha_innobase::commit_inplace_alter_table(
 			logical sense the commit in the file-based
 			data structures happens here. */
 
-			trx_commit_low(trx, &mtr);
+			trx->commit_low(&mtr);
 		}
 
 		/* If server crashes here, the dictionary in

storage/innobase/include/trx0trx.h

@@ -181,17 +181,6 @@ trx_start_for_ddl_low(
 	trx_start_for_ddl_low((t), (o))
 #endif /* UNIV_DEBUG */
 
-/****************************************************************//**
-Commits a transaction. */
-void
-trx_commit(
-/*=======*/
-	trx_t*	trx);	/*!< in/out: transaction */
-
-/** Commit a transaction and a mini-transaction.
-@param[in,out]	trx	transaction
-@param[in,out]	mtr	mini-transaction (NULL if no modifications) */
-void trx_commit_low(trx_t* trx, mtr_t* mtr);
 /**********************************************************************//**
 Does the transaction commit for MySQL.
 @return DB_SUCCESS or error number */
@@ -898,10 +887,10 @@ struct trx_t {
 					defer flush of the logs to disk
 					until after we release the
 					mutex. */
-	bool		must_flush_log_later;/*!< this flag is set to TRUE in
-					trx_commit() if flush_log_later was
-					TRUE, and there were modifications by
-					the transaction; in that case we must
+	bool		must_flush_log_later;/*!< set in commit()
+					if flush_log_later was
+					set and redo log was written;
+					in that case we will
 					flush the log in
 					trx_commit_complete_for_mysql() */
 	ulint		duplicates;	/*!< TRX_DUP_IGNORE | TRX_DUP_REPLACE */
@@ -1132,11 +1121,20 @@ struct trx_t {
   @param[in]	table_id	table identifier */
   void evict_table(table_id_t table_id);
 
+private:
+  /** Mark a transaction committed in the main memory data structures. */
+  inline void commit_in_memory(const mtr_t *mtr);
+public:
+  /** Commit the transaction. */
+  void commit();
 
-  bool is_referenced()
-  {
-    return n_ref > 0;
-  }
+  /** Commit the transaction in a mini-transaction.
+  @param mtr  mini-transaction (if there are any persistent modifications) */
+  void commit_low(mtr_t *mtr= nullptr);
+
+
+
+  bool is_referenced() const { return n_ref > 0; }
 
 
   void reference()

storage/innobase/lock/lock0lock.cc

@@ -6865,7 +6865,7 @@ DeadlockChecker::trx_rollback()
 
 	print("*** WE ROLL BACK TRANSACTION (1)\n");
 #ifdef WITH_WSREP
-	if (wsrep_on(trx->mysql_thd) && wsrep_thd_is_SR(trx->mysql_thd)) {
+	if (trx->is_wsrep() && wsrep_thd_is_SR(trx->mysql_thd)) {
 		wsrep_handle_SR_rollback(m_start->mysql_thd, trx->mysql_thd);
 	}
 #endif
@@ -6956,8 +6956,7 @@ DeadlockChecker::check_and_resolve(const lock_t* lock, trx_t* trx)
 
 		print("*** WE ROLL BACK TRANSACTION (2)\n");
 #ifdef WITH_WSREP
-		if (wsrep_on(trx->mysql_thd)
-		    && wsrep_thd_is_SR(trx->mysql_thd)) {
+		if (trx->is_wsrep() && wsrep_thd_is_SR(trx->mysql_thd)) {
 			wsrep_handle_SR_rollback(trx->mysql_thd,
 						 victim_trx->mysql_thd);
 		}

storage/innobase/trx/trx0roll.cc

@@ -59,7 +59,7 @@ static bool trx_rollback_finish(trx_t* trx)
 	trx->mod_tables.clear();
 	bool finished = trx->error_state == DB_SUCCESS;
 	if (UNIV_LIKELY(finished)) {
-		trx_commit(trx);
+		trx->commit();
 	} else {
 		ut_a(trx->error_state == DB_INTERRUPTED);
 		ut_ad(!srv_is_being_started);
@@ -84,7 +84,7 @@ static bool trx_rollback_finish(trx_t* trx)
 			ut_free(undo);
 			undo = NULL;
 		}
-		trx_commit_low(trx, NULL);
+		trx->commit_low();
 	}
 
 	trx->lock.que_state = TRX_QUE_RUNNING;