Never pass NULL to innobase_get_stmt()

storage/innobase/handler/ha_innodb.cc

@@ -1998,15 +1998,11 @@ innobase_get_stmt(
 	THD*	thd,		/*!< in: MySQL thread handle */
 	size_t*	length)		/*!< out: length of the SQL statement */
 {
-	const char* query = NULL;
-	LEX_STRING *stmt = NULL;
-	ut_ad(thd != NULL);
-	stmt = thd_query_string(thd);
-	if (stmt) {
+	if (const LEX_STRING *stmt = thd_query_string(thd)) {
 		*length = stmt->length;
-		query = stmt->str;
+		return stmt->str;
 	}
-	return (query);
+	return NULL;
 }
 
 /**********************************************************************//**

storage/innobase/lock/lock0lock.cc

@@ -4742,13 +4742,11 @@ lock_rec_unlock(
 	trx_mutex_exit(trx);
 
 	stmt = innobase_get_stmt(trx->mysql_thd, &stmt_len);
-	ut_print_timestamp(stderr);
-	fprintf(stderr,
-		" InnoDB: Error: unlock row could not"
-		" find a %lu mode lock on the record\n",
-		(ulong) lock_mode);
-	ut_print_timestamp(stderr);
-	fprintf(stderr, " InnoDB: current statement: %.*s\n",
+
+	ib_logf(IB_LOG_LEVEL_ERROR,
+		"unlock row could not find a %u mode lock on the record;"
+		" statement=%.*s",
+		lock_mode,
 		(int) stmt_len, stmt);
 
 	return;

storage/innobase/trx/trx0i_s.cc

@@ -503,7 +503,9 @@ fill_trx_row(
 
 	row->trx_mysql_thread_id = thd_get_thread_id(trx->mysql_thd);
 
-	stmt = innobase_get_stmt(trx->mysql_thd, &stmt_len);
+	stmt = trx->mysql_thd
+		? innobase_get_stmt(trx->mysql_thd, &stmt_len)
+		: NULL;
 
 	if (stmt != NULL) {
 		char	query[TRX_I_S_TRX_QUERY_MAX_LEN + 1];

storage/xtradb/handler/ha_innodb.cc

@@ -2324,15 +2324,11 @@ innobase_get_stmt(
 	THD*	thd,		/*!< in: MySQL thread handle */
 	size_t*	length)		/*!< out: length of the SQL statement */
 {
-	const char* query = NULL;
-	LEX_STRING *stmt = NULL;
-	ut_ad(thd != NULL);
-	stmt = thd_query_string(thd);
-	if (stmt) {
+	if (const LEX_STRING *stmt = thd_query_string(thd)) {
 		*length = stmt->length;
-		query = stmt->str;
+		return stmt->str;
 	}
-	return (query);
+	return NULL;
 }
 
 /**********************************************************************//**

storage/xtradb/lock/lock0lock.cc

@@ -4788,13 +4788,11 @@ lock_rec_unlock(
 	trx_mutex_exit(trx);
 
 	stmt = innobase_get_stmt(trx->mysql_thd, &stmt_len);
-	ut_print_timestamp(stderr);
-	fprintf(stderr,
-		" InnoDB: Error: unlock row could not"
-		" find a %lu mode lock on the record\n",
-		(ulong) lock_mode);
-	ut_print_timestamp(stderr);
-	fprintf(stderr, " InnoDB: current statement: %.*s\n",
+
+	ib_logf(IB_LOG_LEVEL_ERROR,
+		"unlock row could not find a %u mode lock on the record;"
+		" statement=%.*s",
+		lock_mode,
 		(int) stmt_len, stmt);
 
 	return;

storage/xtradb/trx/trx0i_s.cc

@@ -507,7 +507,9 @@ fill_trx_row(
 
 	row->trx_mysql_thread_id = thd_get_thread_id(trx->mysql_thd);
 
-	stmt = innobase_get_stmt(trx->mysql_thd, &stmt_len);
+	stmt = trx->mysql_thd
+		? innobase_get_stmt(trx->mysql_thd, &stmt_len)
+		: NULL;
 
 	if (stmt != NULL) {
 		char	query[TRX_I_S_TRX_QUERY_MAX_LEN + 1];