Implementation of WL#1824 "Add replication of character set variables in 4.1",

by binlogging some SET ONE_SHOT CHARACTER_SETetc,
which will be enough until we have it more compact and more complete in 5.0. With the present patch,
replication will work ok between 4.1.3 master and slaves, as long as:
- master and slave have the same GLOBAL.COLLATION_SERVER
- COLLATION_DATABASE and CHARACTER_SET_DATABASE are not used
- application does not use the fact that table is created with charset of the USEd db (BUG#2326).
all of which are not too hard to fulfill. 
ONE_SHOT is reserved for internal use of mysqlbinlog|mysql and works only for charsets,
so we give error if used for non-charset vars.
Fix for BUG#3875 "mysqlbinlog produces wrong ouput  if query uses
 variables containing quotes" and BUG#3943 "Queries with non-ASCII literals are not replicated
 properly after SET NAMES".
Detecting that master and slave have different global charsets or server ids.

1 files changed, 47 insertions, 9 deletions

diff --git a/sql/set_var.h b/sql/set_var.h
index 699f320bbd9..64bdfdb718b 100644
--- a/sql/set_var.h
+++ b/sql/set_var.h
@@ -49,10 +49,20 @@ public:
   const char *name;
   
   sys_after_update_func after_update;
-  sys_var(const char *name_arg) :name(name_arg),after_update(0)
-  {}
+#if MYSQL_VERSION_ID < 50000
+  bool no_support_one_shot;
+#endif
+  sys_var(const char *name_arg)
+    :name(name_arg), after_update(0)
+#if MYSQL_VERSION_ID < 50000
+    , no_support_one_shot(1)
+#endif
+    {}
   sys_var(const char *name_arg,sys_after_update_func func)
-    :name(name_arg),after_update(func)
+    :name(name_arg), after_update(func)
+#if MYSQL_VERSION_ID < 50000
+    , no_support_one_shot(1)
+#endif
   {}
   virtual ~sys_var() {}
   virtual bool check(THD *thd, set_var *var);
@@ -487,12 +497,17 @@ public:
 class sys_var_collation :public sys_var_thd
 {
 public:
-  sys_var_collation(const char *name_arg) :sys_var_thd(name_arg) {}
+  sys_var_collation(const char *name_arg) :sys_var_thd(name_arg)
+    {
+#if MYSQL_VERSION_ID < 50000
+    no_support_one_shot= 0;
+#endif
+    }
   bool check(THD *thd, set_var *var);
 SHOW_TYPE type() { return SHOW_CHAR; }
   bool check_update_type(Item_result type)
   {
-    return type != STRING_RESULT;		/* Only accept strings */
+    return ((type != STRING_RESULT) && (type != INT_RESULT));
   }
   bool check_default(enum_var_type type) { return 0; }
   virtual void set_default(THD *thd, enum_var_type type)= 0;
@@ -502,13 +517,23 @@ class sys_var_character_set :public sys_var_thd
 {
 public:
   bool nullable;
-  sys_var_character_set(const char *name_arg) :sys_var_thd(name_arg) 
-  { nullable= 0; }
+  sys_var_character_set(const char *name_arg) :
+    sys_var_thd(name_arg)
+  {
+    nullable= 0;
+#if MYSQL_VERSION_ID < 50000
+    /*
+      In fact only almost all variables derived from sys_var_character_set
+      support ONE_SHOT; character_set_results doesn't. But that's good enough.
+    */
+    no_support_one_shot= 0;
+#endif
+  }
   bool check(THD *thd, set_var *var);
   SHOW_TYPE type() { return SHOW_CHAR; }
   bool check_update_type(Item_result type)
   {
-    return type != STRING_RESULT;		/* Only accept strings */
+    return ((type != STRING_RESULT) && (type != INT_RESULT));
   }
   bool check_default(enum_var_type type) { return 0; }
   bool update(THD *thd, set_var *var);
@@ -541,6 +566,9 @@ class sys_var_character_set_server :public sys_var_character_set
 public:
   sys_var_character_set_server(const char *name_arg) :
     sys_var_character_set(name_arg) {}
+#if defined(HAVE_REPLICATION) && (MYSQL_VERSION_ID < 50000)
+  bool check(THD *thd, set_var *var);
+#endif
   void set_default(THD *thd, enum_var_type type);
   CHARSET_INFO **ci_ptr(THD *thd, enum_var_type type);
 };
@@ -576,6 +604,9 @@ class sys_var_collation_server :public sys_var_collation
 {
 public:
   sys_var_collation_server(const char *name_arg) :sys_var_collation(name_arg) {}
+#if defined(HAVE_REPLICATION) && (MYSQL_VERSION_ID < 50000)
+  bool check(THD *thd, set_var *var);
+#endif
   bool update(THD *thd, set_var *var);
   void set_default(THD *thd, enum_var_type type);
   byte *value_ptr(THD *thd, enum_var_type type, LEX_STRING *base);
@@ -689,7 +720,10 @@ public:
   virtual int check(THD *thd)=0;	/* To check privileges etc. */
   virtual int update(THD *thd)=0;	/* To set the value */
   /* light check for PS */
-  virtual   int light_check(THD *thd) { return check(thd); }
+  virtual int light_check(THD *thd) { return check(thd); }
+#if MYSQL_VERSION_ID < 50000
+  virtual bool no_support_one_shot() { return 1; }
+#endif
 };
 
 
@@ -731,6 +765,9 @@ public:
   int check(THD *thd);
   int update(THD *thd);
   int light_check(THD *thd);
+#if MYSQL_VERSION_ID < 50000
+  bool no_support_one_shot() { return var->no_support_one_shot; }
+#endif
 };
 
 
@@ -833,6 +870,7 @@ void set_var_init();
 void set_var_free();
 sys_var *find_sys_var(const char *str, uint length=0);
 int sql_set_variables(THD *thd, List<set_var_base> *var_list);
+bool not_all_support_one_shot(List<set_var_base> *var_list);
 void fix_delay_key_write(THD *thd, enum_var_type type);
 ulong fix_sql_mode(ulong sql_mode);
 extern sys_var_str sys_charset_system;