Bug#35224: mysqldump --help is very confusing

  
The presence of "--skip" parameters is obscure, when it should be
obvious from the text.
  
Now, for boolean options, when they're default to ON and the --skip
is more useful parameter, then tell the user of its existence.

Backported from 6.0-codebase, revid  2572.14.1

client/mysqlcheck.c

@@ -128,7 +128,7 @@ static struct my_option my_long_options[] =
    "Faster than extended-check, but only finds 99.99 percent of all errors. Should be good enough for most cases.",
    0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"write-binlog", OPT_WRITE_BINLOG,
-   "Log ANALYZE, OPTIMIZE and REPAIR TABLE commands. Enabled by default; use --skip-write-binlog when commands should not be sent to replication slaves.",
+   "Log ANALYZE, OPTIMIZE and REPAIR TABLE commands. Use --skip-write-binlog when commands should not be sent to replication slaves.",
    (uchar**) &opt_write_binlog, (uchar**) &opt_write_binlog, 0, GET_BOOL, NO_ARG,
    1, 0, 0, 0, 0, 0},
   {"optimize", 'o', "Optimize table.", 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0,

client/mysqldump.c

@@ -402,7 +402,7 @@ static struct my_option my_long_options[] =
      (uchar**) &opt_routines, (uchar**) &opt_routines, 0, GET_BOOL,
      NO_ARG, 0, 0, 0, 0, 0, 0},
   {"set-charset", OPT_SET_CHARSET,
-   "Add 'SET NAMES default_character_set' to the output. Enabled by default; suppress with --skip-set-charset.",
+   "Add 'SET NAMES default_character_set' to the output.",
    (uchar**) &opt_set_charset, (uchar**) &opt_set_charset, 0, GET_BOOL, NO_ARG, 1,
    0, 0, 0, 0, 0},
   {"set-variable", 'O',

mysys/my_getopt.c

@@ -1220,6 +1220,14 @@ void my_print_help(const struct my_option *options)
       printf("%s", comment);
     }
     putchar('\n');
+    if ((optp->var_type & GET_TYPE_MASK) == GET_NO_ARG ||
+             (optp->var_type & GET_TYPE_MASK) == GET_BOOL)
+    {
+      if (optp->def_value != 0)
+      {
+        printf("%*s(Defaults to on; use --skip-%s to disable.)\n", name_space, "", optp->name);
+      }
+    }
   }
 }