Stage 2 of MDEV-6152:

- Added mem_root to all calls to new Item
- Added private method operator new(size_t size) to Item to ensure that
  we always use a mem_root when creating an item.

This saves use once call to current_thd per Item creation

1 files changed, 29 insertions, 16 deletions

diff --git a/sql/sql_help.cc b/sql/sql_help.cc
index 0c74f3385eb..eb0e260c3f4 100644
--- a/sql/sql_help.cc
+++ b/sql/sql_help.cc
@@ -93,7 +93,7 @@ static bool init_fields(THD *thd, TABLE_LIST *tables,
   for (; count-- ; find_fields++)
   {
     /* We have to use 'new' here as field will be re_linked on free */
-    Item_field *field= new Item_field(thd, context,
+    Item_field *field= new (thd->mem_root) Item_field(thd, context,
                                       "mysql", find_fields->table_name,
                                       find_fields->field_name);
     if (!(find_fields->field= find_field_in_tables(thd, field, tables, NULL,
@@ -450,11 +450,13 @@ void get_all_items_for_category(THD *thd, TABLE *items, Field *pfname,
 int send_answer_1(Protocol *protocol, String *s1, String *s2, String *s3)
 {
   THD *thd= protocol->thd;
+  MEM_ROOT *mem_root= thd->mem_root;
   DBUG_ENTER("send_answer_1");
+
   List<Item> field_list;
-  field_list.push_back(new Item_empty_string(thd, "name", 64));
-  field_list.push_back(new Item_empty_string(thd, "description", 1000));
-  field_list.push_back(new Item_empty_string(thd, "example", 1000));
+  field_list.push_back(new (mem_root) Item_empty_string(thd, "name", 64));
+  field_list.push_back(new (mem_root) Item_empty_string(thd, "description", 1000));
+  field_list.push_back(new (mem_root) Item_empty_string(thd, "example", 1000));
 
   if (protocol->send_result_set_metadata(&field_list,
                             Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
@@ -494,13 +496,14 @@ int send_answer_1(Protocol *protocol, String *s1, String *s2, String *s3)
 int send_header_2(Protocol *protocol, bool for_category)
 {
   THD *thd= protocol->thd;
+  MEM_ROOT *mem_root= thd->mem_root;
   DBUG_ENTER("send_header_2");
   List<Item> field_list;
   if (for_category)
-    field_list.push_back(new Item_empty_string(thd, "source_category_name",
+    field_list.push_back(new (mem_root) Item_empty_string(thd, "source_category_name",
                                                64));
-  field_list.push_back(new Item_empty_string(thd, "name", 64));
-  field_list.push_back(new Item_empty_string(thd, "is_it_category", 1));
+  field_list.push_back(new (mem_root) Item_empty_string(thd, "name", 64));
+  field_list.push_back(new (mem_root) Item_empty_string(thd, "is_it_category", 1));
   DBUG_RETURN(protocol->send_result_set_metadata(&field_list, Protocol::SEND_NUM_ROWS |
                                                  Protocol::SEND_EOF));
 }
@@ -628,11 +631,15 @@ SQL_SELECT *prepare_select_for_name(THD *thd, const char *mask, uint mlen,
 				    TABLE_LIST *tables, TABLE *table,
 				    Field *pfname, int *error)
 {
-  Item *cond= new Item_func_like(thd, new Item_field(thd, pfname),
-                                 new Item_string(thd, mask, mlen,
-                                                 pfname->charset()),
-                                 new Item_string_ascii(thd, "\\"),
-                                 FALSE);
+  MEM_ROOT *mem_root= thd->mem_root;
+  Item *cond= new (mem_root)
+    Item_func_like(thd,
+                   new (mem_root)
+                   Item_field(thd, pfname),
+                   new (mem_root) Item_string(thd, mask, mlen,
+                                              pfname->charset()),
+                   new (mem_root) Item_string_ascii(thd, "\\"),
+                   FALSE);
   if (thd->is_fatal_error)
     return 0;					// OOM
   return prepare_simple_select(thd, cond, table, error);
@@ -767,11 +774,17 @@ bool mysqld_help(THD *thd, const char *mask)
     {
       Field *topic_cat_id= used_fields[help_topic_help_category_id].field;
       Item *cond_topic_by_cat=
-        new Item_func_equal(thd, new Item_field(thd, topic_cat_id),
-                            new Item_int(thd, (int32) category_id));
+        new (mem_root)
+        Item_func_equal(thd,
+                        new (mem_root)
+                        Item_field(thd, topic_cat_id),
+                        new (mem_root)
+                        Item_int(thd, (int32) category_id));
       Item *cond_cat_by_cat=
-        new Item_func_equal(thd, new Item_field(thd, cat_cat_id),
-                            new Item_int(thd, (int32) category_id));
+        new (mem_root)
+        Item_func_equal(thd,
+                        new (mem_root) Item_field(thd, cat_cat_id),
+                        new (mem_root) Item_int(thd, (int32) category_id));
       if (!(select= prepare_simple_select(thd, cond_topic_by_cat,
                                           tables[0].table, &error)))
         goto error;