1 files changed, 67 insertions, 29 deletions

diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index aedff648e5c..ecaab9db0cd 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -94,6 +94,71 @@ static void make_unique_view_field_name(Item *target,
   target->set_name(buff, name_len, system_charset_info);
 }
 
+
+/*
+  Check if items with same names are present in list and possibly
+  generate unique names for them.
+
+  SYNOPSIS
+    item_list             list of Items which should be checked for duplicates
+    gen_unique_view_name  flag: generate unique name or return with error when
+                          duplicate names are found.
+
+  DESCRIPTION
+    This function is used on view creation and preparation of derived tables.
+    It checks item_list for items with duplicate names. If it founds two
+    items with same name and conversion to unique names isn't allowed, or
+    names for both items are set by user - function fails.
+    Otherwise it generates unique name for one item with autogenerated name
+    using make_unique_view_field_name()
+
+  RETURN VALUE
+    FALSE no duplicate names found, or they are converted to unique ones
+    TRUE  duplicate names are found and they can't be converted or conversion
+          isn't allowed
+*/
+
+bool check_duplicate_names(List<Item> &item_list, bool gen_unique_view_name)
+{
+  DBUG_ENTER("check_duplicate_names");
+  /* Test absence of duplicates names */
+  {
+    Item *item;
+    List_iterator_fast<Item> it(item_list);
+    List_iterator_fast<Item> itc(item_list);
+    while ((item= it++))
+    {
+      Item *check;
+      /* treat underlying fields like set by user names */
+      if (item->real_item()->type() == Item::FIELD_ITEM)
+        item->is_autogenerated_name= FALSE;
+      itc.rewind();
+      while ((check= itc++) && check != item)
+      {
+        if (my_strcasecmp(system_charset_info, item->name, check->name) == 0)
+        {
+          if (!gen_unique_view_name)
+          {
+            my_error(ER_DUP_FIELDNAME, MYF(0), item->name);
+            DBUG_RETURN(TRUE);
+          }
+          else if (item->is_autogenerated_name)
+            make_unique_view_field_name(item, item_list, item);
+          else if (check->is_autogenerated_name)
+            make_unique_view_field_name(check, item_list, item);
+          else
+          {
+            my_error(ER_DUP_FIELDNAME, MYF(0), item->name);
+            DBUG_RETURN(TRUE);
+          }
+        }
+      }
+    }
+  }
+  DBUG_RETURN(FALSE);
+}
+
+
 /*
   Creating/altering VIEW procedure
 
@@ -308,35 +373,8 @@ bool mysql_create_view(THD *thd,
     }
   }
 
-  /* Test absence of duplicates names */
-  {
-    Item *item;
-    List_iterator_fast<Item> it(select_lex->item_list);
-    List_iterator_fast<Item> itc(select_lex->item_list);
-    while ((item= it++))
-    {
-      Item *check;
-      /* treat underlying fields like set by user names */
-      if (item->real_item()->type() == Item::FIELD_ITEM)
-        item->is_autogenerated_name= FALSE;
-      itc.rewind();
-      while ((check= itc++) && check != item)
-      {
-        if (my_strcasecmp(system_charset_info, item->name, check->name) == 0)
-        {
-          if (item->is_autogenerated_name)
-            make_unique_view_field_name(item, select_lex->item_list, item);
-          else if (check->is_autogenerated_name)
-            make_unique_view_field_name(check, select_lex->item_list, item);
-          else
-          {
-            my_error(ER_DUP_FIELDNAME, MYF(0), item->name);
-            DBUG_RETURN(TRUE);
-          }
-        }
-      }
-    }
-  }
+  if (check_duplicate_names(select_lex->item_list, 1))
+    DBUG_RETURN(TRUE);
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   /*