be less annoying about sysvar-based table attributes

do not *always* add them to the create table definition,
but only when a sysvar value is different from a default.

also, when adding them - don't quote numbers

mysql-test/r/partition_example.result

@@ -7,7 +7,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) NOT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1
 /*!50100 PARTITION BY LIST (a)
 (PARTITION p0 VALUES IN (1) ENGINE = EXAMPLE,
  PARTITION p1 VALUES IN (2) ENGINE = EXAMPLE) */
@@ -20,7 +20,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) NOT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=12340 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=12340
 /*!50100 PARTITION BY LIST (a)
 (PARTITION p0 VALUES IN (1) ENGINE = EXAMPLE,
  PARTITION p1 VALUES IN (2) ENGINE = EXAMPLE) */

mysql-test/r/plugin.result

@@ -127,7 +127,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL `complex`='c,f,f,f'
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=10000 `STR`='dskj' `one_or_two`='one' `YESNO`=0 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=10000 `STR`='dskj' `one_or_two`='one' `YESNO`=0
 drop table t1;
 SET @OLD_SQL_MODE=@@SQL_MODE;
 SET SQL_MODE='IGNORE_BAD_TABLE_OPTIONS';
@@ -142,7 +142,7 @@ Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL,
   `b` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=10000000000000000000 `one_or_two`='ttt' `YESNO`=SSS `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=10000000000000000000 `one_or_two`='ttt' `YESNO`=SSS
 #alter table
 alter table t1 ULL=10000000;
 Warnings:
@@ -152,7 +152,7 @@ Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL,
   `b` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `one_or_two`='ttt' `YESNO`=SSS `VAROPT`='5' `ULL`=10000000
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `one_or_two`='ttt' `YESNO`=SSS `ULL`=10000000
 alter table t1 change a a int complex='c,c,c';
 Warnings:
 Note	1105	EXAMPLE DEBUG: Field `a` COMPLEX '(null)' -> 'c,c,c'
@@ -161,14 +161,14 @@ Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL `complex`='c,c,c',
   `b` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `one_or_two`='ttt' `YESNO`=SSS `VAROPT`='5' `ULL`=10000000
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `one_or_two`='ttt' `YESNO`=SSS `ULL`=10000000
 alter table t1 one_or_two=two;
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL `complex`='c,c,c',
   `b` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `YESNO`=SSS `VAROPT`='5' `ULL`=10000000 `one_or_two`=two
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `YESNO`=SSS `ULL`=10000000 `one_or_two`=two
 drop table t1;
 #illegal value error
 SET SQL_MODE='';
@@ -183,11 +183,11 @@ SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=4660 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ULL`=4660
 SET example_varopt_default=33;
 select create_options from information_schema.tables where table_schema='test' and table_name='t1';
 create_options
-`ULL`=4660 `VAROPT`='5'
+`ULL`=4660
 ALTER TABLE t1 ULL=DEFAULT;
 Warnings:
 Note	1105	EXAMPLE DEBUG: ULL 4660 -> 4294967295
@@ -195,14 +195,14 @@ SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1
 DROP TABLE t1;
 create table t1 (a int) engine=example;
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`='33'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`=33
 drop table t1;
 create table t1 (a int) engine=example varopt=15;
 show create table t1;
@@ -215,7 +215,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`='33'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `VAROPT`=33
 drop table t1;
 SET @@SQL_MODE=@OLD_SQL_MODE;
 select 1;

mysql-test/r/table_options-5867.result

@@ -14,7 +14,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL `complex`='c,f,f,f' `invalid`=3
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=10000 `str`='dskj' `one_or_two`='one' `yesno`=0 `foobar`=barfoo `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=10000 `str`='dskj' `one_or_two`='one' `yesno`=0 `foobar`=barfoo
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (
@@ -26,7 +26,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL `complex`='c,f,f,f' /* `invalid`=3 */
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=10000 `str`='dskj' `one_or_two`='one' `yesno`=0 /* `foobar`=barfoo */ `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=10000 `str`='dskj' `one_or_two`='one' `yesno`=0 /* `foobar`=barfoo */
 show create table t2;
 Table	Create Table
 t2	CREATE TABLE `t2` (

mysql-test/suite/rpl/r/rpl_table_options.result

@@ -7,7 +7,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) NOT NULL
-) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=12340 `VAROPT`='5'
+) ENGINE=EXAMPLE DEFAULT CHARSET=latin1 `ull`=12340
 show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (

sql/create_options.cc

@@ -297,8 +297,7 @@ bool parse_option_list(THD* thd, handlerton *hton, void *option_struct_arg,
                        (uchar*)val->name.str, val->name.length))
         continue;
 
-      seen=true;
-
+      /* skip duplicates (see engine_option_value constructor above) */
       if (val->parsed && !val->value.str)
         continue;
 
@@ -306,39 +305,58 @@ bool parse_option_list(THD* thd, handlerton *hton, void *option_struct_arg,
                         *option_struct, suppress_warning || val->parsed, root))
         DBUG_RETURN(TRUE);
       val->parsed= true;
+      seen=true;
       break;
     }
-    if (!seen)
+    if (!seen || (opt->var && !last->value.str))
     {
       LEX_STRING default_val= null_lex_str;
 
       /*
-        If it's CREATE/ALTER TABLE parsing mode (options are created in the
-        transient thd->mem_root, not in the long living TABLE_SHARE::mem_root),
-        and variable-backed option was not explicitly set.
-
-        If it's not create, but opening of the existing frm (that was,
-        probably, created with the older version of the storage engine and
-        does not have this option stored), we take the *default* value of the
-        sysvar, not the *current* value. Because we don't want to have
-        different option values for the same table if it's opened many times.
+        Okay, here's the logic for sysvar options:
+        1. When we parse CREATE TABLE and sysvar option was not explicitly
+           mentioned we add it to the list as if it was specified with the
+           *current* value of the underlying sysvar.
+        2. But only if the underlying sysvar value is different from the
+           sysvar's default.
+        3. If it's ALTER TABLE and the sysvar option was not explicitly
+           mentioned - do nothing, do not add it to the list.
+        4. But if it was ALTER TABLE with sysvar option = DEFAULT, we
+           add it to the list (under the same condition #2).
+        5. If we're here parsing the option list from the .frm file
+           for a normal open_table() and the sysvar option was not there -
+           do not add it to the list (makes no sense anyway) and
+           use the *default* value of the underlying sysvar. Because
+           sysvar value can change, but it should not affect existing tables.
+
+        This is how it's implemented: the current sysvar value is added
+        to the list if suppress_warning is FALSE (meaning a table is created,
+        that is CREATE TABLE or ALTER TABLE) and it's actually a CREATE TABLE
+        command or it's an ALTER TABLE and the option was seen (=DEFAULT).
+
+        Note that if the option was set explicitly (not =DEFAULT) it wouldn't
+        have passes the if() condition above.
       */
-      if (root == thd->mem_root && opt->var)
+      if (!suppress_warning && opt->var &&
+          (thd->lex->sql_command == SQLCOM_CREATE_TABLE || seen))
       {
         // take a value from the variable and add it to the list
         sys_var *sysvar= find_hton_sysvar(hton, opt->var);
         DBUG_ASSERT(sysvar);
 
-        char buf[256];
-        String sbuf(buf, sizeof(buf), system_charset_info), *str;
-        if ((str= sysvar->val_str(&sbuf, thd, OPT_SESSION, &null_lex_str)))
+        if (!sysvar->session_is_default(thd))
         {
-          LEX_STRING name= { const_cast<char*>(opt->name), opt->name_length };
-          default_val.str= strmake_root(root, str->ptr(), str->length());
-          default_val.length= str->length();
-          val= new (root) engine_option_value(name, default_val, true,
-                                              option_list, &last);
-          val->parsed= true;
+          char buf[256];
+          String sbuf(buf, sizeof(buf), system_charset_info), *str;
+          if ((str= sysvar->val_str(&sbuf, thd, OPT_SESSION, &null_lex_str)))
+          {
+            LEX_STRING name= { const_cast<char*>(opt->name), opt->name_length };
+            default_val.str= strmake_root(root, str->ptr(), str->length());
+            default_val.length= str->length();
+            val= new (root) engine_option_value(name, default_val,
+                         opt->type != HA_OPTION_TYPE_ULL, option_list, &last);
+            val->parsed= true;
+          }
         }
       }
       set_one_value(opt, thd, &default_val, *option_struct,

sql/sql_plugin.cc

@@ -307,6 +307,7 @@ public:
   virtual void global_save_default(THD *thd, set_var *var) {}
   bool session_update(THD *thd, set_var *var);
   bool global_update(THD *thd, set_var *var);
+  bool session_is_default(THD *thd);
 };
 
 
@@ -3340,6 +3341,39 @@ uchar* sys_var_pluginvar::real_value_ptr(THD *thd, enum_var_type type)
 }
 
 
+bool sys_var_pluginvar::session_is_default(THD *thd)
+{
+  uchar *value= plugin_var->flags & PLUGIN_VAR_THDLOCAL
+                ? intern_sys_var_ptr(thd, *(int*) (plugin_var+1), true)
+                : *(uchar**) (plugin_var+1);
+
+    real_value_ptr(thd, OPT_SESSION);
+
+  switch (plugin_var->flags & PLUGIN_VAR_TYPEMASK) {
+  case PLUGIN_VAR_BOOL:
+    return option.def_value == *(my_bool*)value;
+  case PLUGIN_VAR_INT:
+    return option.def_value == *(int*)value;
+  case PLUGIN_VAR_LONG:
+  case PLUGIN_VAR_ENUM:
+    return option.def_value == *(long*)value;
+  case PLUGIN_VAR_LONGLONG:
+  case PLUGIN_VAR_SET:
+    return option.def_value == *(longlong*)value;
+  case PLUGIN_VAR_STR:
+    {
+      const char *a=(char*)option.def_value;
+      const char *b=(char*)value;
+      return (!a && !b) || (a && b && strcmp(a,b));
+    }
+  case PLUGIN_VAR_DOUBLE:
+    return getopt_ulonglong2double(option.def_value) == *(double*)value;
+  default:
+    DBUG_ASSERT(0);
+  }
+}
+
+
 TYPELIB* sys_var_pluginvar::plugin_var_typelib(void)
 {
   switch (plugin_var->flags & (PLUGIN_VAR_TYPEMASK | PLUGIN_VAR_THDLOCAL)) {