errmsg.txt:

  Correct a misleading error message about max row length

sql/share/english/errmsg.txt

@@ -119,7 +119,7 @@
 "Unknown character set: '%-.64s'",
 "Too many tables. MySQL can only use %d tables in a join",
 "Too many columns",
-"Too big row size. The maximum row size, not counting BLOBs, is %d. You have to change some fields to BLOBs",
+"Too big row size. The maximum row size, not counting BLOBs, is %d (can be lower for some table types). You have to change some fields to BLOBs",
 "Thread stack overrun:  Used: %ld of a %ld stack.  Use 'mysqld -O thread_stack=#' to specify a bigger stack if needed",
 "Cross dependency found in OUTER JOIN.  Examine your ON conditions",
 "Column '%-.64s' is used with UNIQUE or INDEX but is not defined as NOT NULL",