Bug #37339: SHOW VARIABLES not working properly with multi-byte datadir

      
The SHOW VARIABLES LIKE .../SELECT @@/SELECT ... FROM INFORMATION_SCHEMA.VARIABLES
were assuming that all the system variables are in system charset (UTF-8).
However the variables that are settable through command line will have a different
character set (character_set_filesystem).
Fixed the server to remember the correct character set of basedir, datadir, tmpdir,
ssl, plugin_dir, slave_load_tmpdir, innodb variables; init_connect and init_slave 
variables and use it when processing data.

mysql-test/r/ctype_filesystem.result:
  Bug #37339: test case (should be in utf-8)
mysql-test/t/ctype_filesystem-master.opt:
  Bug #37339: test case (should be in ISO-8859-1)
mysql-test/t/ctype_filesystem.test:
  Bug #37339: test case
sql/mysqld.cc:
  Bug #37339: remember the correct character set for init_slave and init_connect
sql/set_var.cc:
  Bug #37339: 
    - remember the character set of the relevant variables
    - implement storing and using the correct 
      character set
sql/set_var.h:
  Bug #37339: implement storing and using the correct 
  character set
sql/sql_show.cc:
  Bug #37339: implement storing and using the correct 
  character set

1 files changed, 46 insertions, 1 deletions

diff --git a/sql/set_var.h b/sql/set_var.h
index c37cc400e43..f43d3b75cee 100644
--- a/sql/set_var.h
+++ b/sql/set_var.h
@@ -46,9 +46,17 @@ public:
   
   sys_after_update_func after_update;
   bool no_support_one_shot;
+  /*
+    true if the value is in character_set_filesystem, 
+    false otherwise.
+    Note that we can't use a pointer to the charset as the system var is 
+    instantiated in global scope and the charset pointers are initialized
+    later.
+  */  
+  bool is_os_charset;
   sys_var(const char *name_arg, sys_after_update_func func= NULL)
     :name(name_arg), after_update(func)
-    , no_support_one_shot(1)
+    , no_support_one_shot(1), is_os_charset(FALSE)
   {}
   virtual ~sys_var() {}
   virtual bool check(THD *thd, set_var *var);
@@ -68,6 +76,7 @@ public:
   Item *item(THD *thd, enum_var_type type, LEX_STRING *base);
   virtual bool is_struct() { return 0; }
   virtual bool is_readonly() const { return 0; }
+  CHARSET_INFO *charset(THD *thd);
 };
 
 
@@ -247,6 +256,17 @@ public:
 };
 
 
+class sys_var_const_os_str: public sys_var_const_str
+{
+public:
+  sys_var_const_os_str(const char *name_arg, const char *value_arg)
+    :sys_var_const_str(name_arg, value_arg)
+  { 
+    is_os_charset= TRUE; 
+  }
+};
+
+
 class sys_var_const_str_ptr :public sys_var
 {
 public:
@@ -276,6 +296,17 @@ public:
 };
 
 
+class sys_var_const_os_str_ptr :public sys_var_const_str_ptr
+{
+public:
+  sys_var_const_os_str_ptr(const char *name_arg, char **value_arg)
+    :sys_var_const_str_ptr(name_arg, value_arg)
+  {
+    is_os_charset= TRUE; 
+  }
+};
+
+
 class sys_var_enum :public sys_var
 {
   uint	*value; 
@@ -791,6 +822,20 @@ public:
   bool is_readonly() const { return 1; }
 };
 
+
+class sys_var_readonly_os: public sys_var_readonly
+{
+public:
+  sys_var_readonly_os(const char *name_arg, enum_var_type type,
+		   SHOW_TYPE show_type_arg,
+		   sys_value_ptr_func value_ptr_func_arg)
+    :sys_var_readonly(name_arg, type, show_type_arg, value_ptr_func_arg)
+  {
+    is_os_charset= TRUE;
+  }
+};
+
+
 class sys_var_thd_time_zone :public sys_var_thd
 {
 public: