Fixed bug mdev-354.

Virtual columns of ENUM and SET data types were not supported properly
in the original patch that introduced virtual columns into MariaDB 5.2.
The problem was that for any  virtual column the patch used the 
interval_id field of the definition of the column in the frm file as
a reference to the virtual column expression.
The fix stores the optional interval_id of the virtual column in the
extended header of the virtual column expression. 

1 files changed, 14 insertions, 6 deletions

diff --git a/sql/table.cc b/sql/table.cc
index 5b1db9ef1e4..d950b7a3a4e 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -1257,25 +1257,33 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head,
       {
         /*
           Get virtual column data stored in the .frm file as follows:
-          byte 1      = 1 (always 1 to allow for future extensions)
+          byte 1      = 1 | 2
           byte 2      = sql_type
           byte 3      = flags (as of now, 0 - no flags, 1 - field is physically stored)
-          byte 4-...  = virtual column expression (text data)
+          [byte 4]    = optional interval_id for sql_type (only if byte 1 == 2) 
+          next byte ...  = virtual column expression (text data)
         */
         vcol_info= new Virtual_column_info();
-        if ((uint)vcol_screen_pos[0] != 1)
+        bool opt_interval_id= (uint)vcol_screen_pos[0] == 2;
+        field_type= (enum_field_types) (uchar) vcol_screen_pos[1];
+        if (opt_interval_id)
+          interval_nr= (uint)vcol_screen_pos[3];
+        else if ((uint)vcol_screen_pos[0] != 1)
         {
           error= 4;
           goto free_and_err;
         }
-        field_type= (enum_field_types) (uchar) vcol_screen_pos[1];
         fld_stored_in_db= (bool) (uint) vcol_screen_pos[2];
-        vcol_expr_length= vcol_info_length-(uint)FRM_VCOL_HEADER_SIZE;
+        vcol_expr_length= vcol_info_length -
+                          (uint)(FRM_VCOL_HEADER_SIZE(opt_interval_id));
         if (!(vcol_info->expr_str.str=
               (char *)memdup_root(&share->mem_root,
-                                  vcol_screen_pos+(uint)FRM_VCOL_HEADER_SIZE,
+                                  vcol_screen_pos +
+                                  (uint) FRM_VCOL_HEADER_SIZE(opt_interval_id),
                                   vcol_expr_length)))
           goto free_and_err;
+        if (opt_interval_id)
+          interval_nr= (uint) vcol_screen_pos[3];
         vcol_info->expr_str.length= vcol_expr_length;
         vcol_screen_pos+= vcol_info_length;
         share->vfields++;