don't save vcol flags in frm

this is useless now, flags are recalculated on load anyway.
But storing flags on disk means we cannot easily change (add,
remove, or renumber) them in the new MariaDB version.

Author: vuvova

sql/field.h

@@ -396,7 +396,7 @@ enum Derivation
 /* The length of the header part for each virtual column in the .frm file */
 #define FRM_VCOL_OLD_HEADER_SIZE(b) (3 + MY_TEST(b))
 #define FRM_VCOL_NEW_BASE_SIZE 16
-#define FRM_VCOL_NEW_HEADER_SIZE 7
+#define FRM_VCOL_NEW_HEADER_SIZE 6
 
 class Count_distinct_field;
 

sql/table.cc

@@ -2172,11 +2172,10 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
     while (vcol_screen_pos < vcol_screen_end)
     {
       Virtual_column_info *vcol_info;
-      uint flags=        (uint) vcol_screen_pos[0];
+      uint type=         (uint) vcol_screen_pos[0];
       uint field_nr=     uint2korr(vcol_screen_pos+1);
       uint expr_length=  uint2korr(vcol_screen_pos+3);
-      uint type=         (uint) vcol_screen_pos[5];
-      uint name_length=  (uint) vcol_screen_pos[6];
+      uint name_length=  (uint) vcol_screen_pos[5];
       LEX_STRING name;
       char *expr;
 
@@ -2208,8 +2207,6 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
       vcol_info->expr_str.str=    expr;
       vcol_info->expr_str.length= expr_length;
       vcol_screen_pos+=           expr_length;
-      vcol_info->flags=           flags;
-      vcol_info->stored_in_db= 0;
 
       switch (type) {
       case 0:                                   // Generated virtual field

sql/unireg.cc

@@ -560,10 +560,9 @@ static bool add_expr_length(THD *thd, Virtual_column_info **v_col_ptr,
   pack_expression
 
   The data is stored as:
-  1 byte      flags;  VCOL_NON_DETERMINISTIC, etc
+  1 byte      type  (0 virtual, 1 virtual stored, 2 def, 3 check)
   2 bytes     field_number
   2 bytes     length of expression
-  1 byte      type  (0 virtual, 1 virtual stored, 2 def, 3 check)
   1 byte      length of name
   name
   next bytes  column expression (text data)
@@ -572,15 +571,14 @@ static bool add_expr_length(THD *thd, Virtual_column_info **v_col_ptr,
 static void pack_expression(uchar **buff, Virtual_column_info *vcol,
                             uint offset, uint type)
 {
-  (*buff)[0]= vcol->flags;
+  (*buff)[0]= (uchar) type;
   int2store((*buff)+1,   offset);
   /*
     expr_str.length < 64K as we have checked that the total size of the
     frm file is  < 64K
   */
   int2store((*buff)+3, vcol->expr_str.length);
-  (*buff)[5]= (uchar) type;
-  (*buff)[6]= vcol->name.length;
+  (*buff)[5]= vcol->name.length;
   (*buff)+= FRM_VCOL_NEW_HEADER_SIZE;
   memcpy((*buff), vcol->name.str, vcol->name.length);
   (*buff)+= vcol->name.length;