MDEV-13452 Assertion `!recv_no_log_write' failed in log_reserve_and_open()

The debug flag recv_no_log_write prohibits writes of redo log records for
modifying page data. The debug assertion was failing when fil_names_clear()
was writing the informative MLOG_FILE_NAME and MLOG_CHECKPOINT records
which do not modify any data.

log_reserve_and_open(), log_write_low(): Remove the debug assertion.

log_pad_current_log_block(), mtr_write_log(),
mtr_t::Command::prepare_write(): Add the debug assertion.

storage/innobase/log/log0log.cc

@@ -359,7 +359,6 @@ log_reserve_and_open(
 
 loop:
 	ut_ad(log_mutex_own());
-	ut_ad(!recv_no_log_write);
 
 	if (log_sys->is_extending) {
 		log_mutex_exit();
@@ -416,7 +415,6 @@ log_write_low(
 
 	ut_ad(log_mutex_own());
 part_loop:
-	ut_ad(!recv_no_log_write);
 	/* Calculate a part length */
 
 	data_len = (log->buf_free % OS_FILE_LOG_BLOCK_SIZE) + str_len;
@@ -2291,6 +2289,7 @@ log_pad_current_log_block(void)
 	ulint		i;
 	lsn_t		lsn;
 
+	ut_ad(!recv_no_log_write);
 	/* We retrieve lsn only because otherwise gcc crashed on HP-UX */
 	lsn = log_reserve_and_open(OS_FILE_LOG_BLOCK_SIZE);
 

storage/innobase/mtr/mtr0mtr.cc

@@ -478,6 +478,7 @@ mtr_write_log(
 	const ulint	len = log->size();
 	mtr_write_log_t	write_log;
 
+	ut_ad(!recv_no_log_write);
 	DBUG_PRINT("ib_log",
 		   (ULINTPF " extra bytes written at " LSN_PF,
 		    len, log_sys->lsn));
@@ -799,6 +800,8 @@ mtr_t::release_page(const void* ptr, mtr_memo_type_t type)
 ulint
 mtr_t::Command::prepare_write()
 {
+	ut_ad(!recv_no_log_write);
+
 	switch (m_impl->m_log_mode) {
 	case MTR_LOG_SHORT_INSERTS:
 		ut_ad(0);