Bug #34367: sql/sql_show.cc: create_schema_table should handle

MYSQL_TYPE_NEWDECIMAL

Added support for the type MYSQL_TYPE_NEWDECIMAL. It now works like
MYSQL_TYPE_DECIMAL. Unfortunately there cannot be a test case until
we have a working information_schema plugin as part of the source
distribution.


sql/sql_show.cc:
  Bug#34367: The fix. Corrected wrong comments and a DBUG_ENTER with wrong 
  function name.
sql/table.h:
  Bug#34367: Added comments to st_field_info.

sql/sql_show.cc

@@ -5384,8 +5384,9 @@ ST_SCHEMA_TABLE *get_schema_table(enum enum_schema_tables schema_table_idx)
 
   @param
     thd	       	          thread handler
-  @param
-    schema_table          pointer to 'shema_tables' element
+
+  @param table_list Used to pass I_S table information(fields info, tables
+  parameters etc) and table name.
 
   @retval  \#             Pointer to created table
   @retval  NULL           Can't create table
@@ -5436,6 +5437,7 @@ TABLE *create_schema_table(THD *thd, TABLE_LIST *table_list)
         DBUG_RETURN(NULL);
       break;
     case MYSQL_TYPE_DECIMAL:
+    case MYSQL_TYPE_NEWDECIMAL:
       if (!(item= new Item_decimal((longlong) fields_info->value, false)))
       {
         DBUG_RETURN(0);
@@ -5785,7 +5787,7 @@ int make_schema_select(THD *thd, SELECT_LEX *sel,
 {
   ST_SCHEMA_TABLE *schema_table= get_schema_table(schema_table_idx);
   LEX_STRING db, table;
-  DBUG_ENTER("mysql_schema_select");
+  DBUG_ENTER("make_schema_select");
   DBUG_PRINT("enter", ("mysql_schema_select: %s", schema_table->table_name));
   /*
      We have to make non const db_name & table_name

sql/table.h

@@ -759,12 +759,36 @@ enum enum_schema_tables
 
 typedef struct st_field_info
 {
+  /** 
+      This is used as column name. 
+  */
   const char* field_name;
+  /**
+     For string-type columns, this is the maximum number of
+     characters. Otherwise, it is the 'display-length' for the column.
+  */
   uint field_length;
+  /**
+     This denotes data type for the column. For the most part, there seems to
+     be one entry in the enum for each SQL data type, although there seem to
+     be a number of additional entries in the enum.
+  */
   enum enum_field_types field_type;
   int value;
+  /**
+     This is used to set column attributes. By default, columns are @c NOT
+     @c NULL and @c SIGNED, and you can deviate from the default
+     by setting the appopriate flags. You can use either one of the flags
+     @c MY_I_S_MAYBE_NULL and @cMY_I_S_UNSIGNED or
+     combine them using the bitwise or operator @c |. Both flags are
+     defined in table.h.
+   */
   uint field_flags;        // Field atributes(maybe_null, signed, unsigned etc.)
   const char* old_name;
+  /**
+     This should be one of @c SKIP_OPEN_TABLE,
+     @c OPEN_FRM_ONLY or @c OPEN_FULL_TABLE.
+  */
   uint open_method;
 } ST_FIELD_INFO;