fixed merged view fields names (BUG#5147)

support of merged VIEW over several tables added (WL#1809)

1 files changed, 30 insertions, 4 deletions

diff --git a/sql/item.cc b/sql/item.cc
index cbb760156b3..1e8b4d8630d 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -45,12 +45,11 @@ void item_init(void)
 }
 
 Item::Item():
-  name_length(0), fixed(0)
+  name(0), orig_name(0), name_length(0), fixed(0)
 {
   marker= 0;
   maybe_null=null_value=with_sum_func=unsigned_flag=0;
   collation.set(default_charset(), DERIVATION_COERCIBLE);
-  name= 0;
   decimals= 0; max_length= 0;
 
   /* Put item in free list so that we can free all items at end */
@@ -80,6 +79,7 @@ Item::Item():
 Item::Item(THD *thd, Item *item):
   str_value(item->str_value),
   name(item->name),
+  orig_name(item->orig_name),
   max_length(item->max_length),
   marker(item->marker),
   decimals(item->decimals),
@@ -110,12 +110,35 @@ void Item::print_item_w_name(String *str)
 void Item::cleanup()
 {
   DBUG_ENTER("Item::cleanup");
-  DBUG_PRINT("info", ("Item: 0x%lx", this));
-  DBUG_PRINT("info", ("Type: %d", (int)type()));
+  DBUG_PRINT("info", ("Item: 0x%lx, Type: %d, name %s, original name %s",
+		      this, (int)type(), name, orig_name));
   fixed=0;
+  if (orig_name)
+    name= orig_name;
   DBUG_VOID_RETURN;
 }
 
+
+/*
+  rename item (used for views, cleanup() return original name)
+
+  SYNOPSIS
+    Item::rename()
+    new_name	new name of item;
+*/
+
+void Item::rename(char *new_name)
+{
+  /*
+    we can compare pointers to names here, bacause if name was not changed,
+    pointer will be same
+  */
+  if (!orig_name && new_name != name)
+    orig_name= name;
+  name= new_name;
+}
+
+
 Item_ident::Item_ident(const char *db_name_par,const char *table_name_par,
 		       const char *field_name_par)
   :orig_db_name(db_name_par), orig_table_name(table_name_par), 
@@ -2279,6 +2302,9 @@ void Item_ref::cleanup()
   DBUG_ENTER("Item_ref::cleanup");
   Item_ident::cleanup();
   result_field= 0;
+  DBUG_PRINT("info", ("hook: 0x%lx(0x%lx) original item: 0x%lx",
+		      (ulong)hook_ptr, (ulong)(hook_ptr?*hook_ptr:0),
+		      (ulong)orig_item));
   if (hook_ptr)
     *hook_ptr= orig_item;
   DBUG_VOID_RETURN;