Bug#25122: Views based on a self-joined table aren't insertable.

When INSERT is done over a view the table being inserted into is 
checked to be unique among all views tables. But if the view contains
self-joined table an error will be thrown even if all tables are used under
different aliases.

The unique_table() function now also checks tables' aliases when needed.

sql/mysql_priv.h

@@ -1064,7 +1064,8 @@ TABLE_LIST *find_table_in_list(TABLE_LIST *table,
                                st_table_list *TABLE_LIST::*link,
                                const char *db_name,
                                const char *table_name);
-TABLE_LIST *unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list);
+TABLE_LIST *unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
+                         bool check_alias);
 TABLE **find_temporary_table(THD *thd, const char *db, const char *table_name);
 bool close_temporary_table(THD *thd, const char *db, const char *table_name);
 void close_temporary(TABLE *table, bool delete_table);

sql/sql_base.cc

@@ -796,6 +796,7 @@ TABLE_LIST *find_table_in_list(TABLE_LIST *table,
     thd                   thread handle
     table                 table which should be checked
     table_list            list of tables
+    check_alias           whether to check tables' aliases
 
   NOTE: to exclude derived tables from check we use following mechanism:
     a) during derived table processing set THD::derived_tables_processing
@@ -823,10 +824,11 @@ TABLE_LIST *find_table_in_list(TABLE_LIST *table,
     0 if table is unique
 */
 
-TABLE_LIST* unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list)
+TABLE_LIST* unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
+                         bool check_alias)
 {
   TABLE_LIST *res;
-  const char *d_name, *t_name;
+  const char *d_name, *t_name, *t_alias;
   DBUG_ENTER("unique_table");
   DBUG_PRINT("enter", ("table alias: %s", table->alias));
 
@@ -854,6 +856,7 @@ TABLE_LIST* unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list)
   }
   d_name= table->db;
   t_name= table->table_name;
+  t_alias= table->alias;
 
   DBUG_PRINT("info", ("real table: %s.%s", d_name, t_name));
   for (;;)
@@ -861,6 +864,8 @@ TABLE_LIST* unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list)
     if (((! (res= find_table_in_global_list(table_list, d_name, t_name))) &&
          (! (res= mysql_lock_have_duplicate(thd, table, table_list)))) ||
         ((!res->table || res->table != table->table) &&
+         (!check_alias || !(lower_case_table_names ?
+          strcasecmp(t_alias, res->alias) : strcmp(t_alias, res->alias))) &&
          res->select_lex && !res->select_lex->exclude_from_table_unique_test &&
          !res->prelocking_placeholder))
       break;

sql/sql_delete.cc

@@ -370,7 +370,7 @@ bool mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
   }
   {
     TABLE_LIST *duplicate;
-    if ((duplicate= unique_table(thd, table_list, table_list->next_global)))
+    if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0)))
     {
       update_non_unique_table_error(table_list, "DELETE", duplicate);
       DBUG_RETURN(TRUE);
@@ -462,7 +462,7 @@ bool mysql_multi_delete_prepare(THD *thd)
     {
       TABLE_LIST *duplicate;
       if ((duplicate= unique_table(thd, target_tbl->correspondent_table,
-                                   lex->query_tables)))
+                                   lex->query_tables, 0)))
       {
         update_non_unique_table_error(target_tbl->correspondent_table,
                                       "DELETE", duplicate);

sql/sql_insert.cc

@@ -1044,7 +1044,7 @@ bool mysql_prepare_insert(THD *thd, TABLE_LIST *table_list,
   {
     Item *fake_conds= 0;
     TABLE_LIST *duplicate;
-    if ((duplicate= unique_table(thd, table_list, table_list->next_global)))
+    if ((duplicate= unique_table(thd, table_list, table_list->next_global, 1)))
     {
       update_non_unique_table_error(table_list, "INSERT", duplicate);
       DBUG_RETURN(TRUE);
@@ -2424,7 +2424,7 @@ select_insert::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
     query
   */
   if (!(lex->current_select->options & OPTION_BUFFER_RESULT) &&
-      unique_table(thd, table_list, table_list->next_global))
+      unique_table(thd, table_list, table_list->next_global, 0))
   {
     /* Using same table for INSERT and SELECT */
     lex->current_select->options|= OPTION_BUFFER_RESULT;

sql/sql_load.cc

@@ -175,7 +175,7 @@ bool mysql_load(THD *thd,sql_exchange *ex,TABLE_LIST *table_list,
     table is marked to be 'used for insert' in which case we should never
     mark this table as as 'const table' (ie, one that has only one row).
   */
-  if (unique_table(thd, table_list, table_list->next_global))
+  if (unique_table(thd, table_list, table_list->next_global, 0))
   {
     my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->table_name);
     DBUG_RETURN(TRUE);

sql/sql_parse.cc

@@ -2993,7 +2993,7 @@ mysql_execute_command(THD *thd)
         if (!(create_info.options & HA_LEX_CREATE_TMP_TABLE))
         {
           TABLE_LIST *duplicate;
-          if ((duplicate= unique_table(thd, create_table, select_tables)))
+          if ((duplicate= unique_table(thd, create_table, select_tables, 0)))
           {
             update_non_unique_table_error(create_table, "CREATE", duplicate);
             res= 1;
@@ -3009,7 +3009,7 @@ mysql_execute_command(THD *thd)
                tab= tab->next_local)
           {
             TABLE_LIST *duplicate;
-            if ((duplicate= unique_table(thd, tab, select_tables)))
+            if ((duplicate= unique_table(thd, tab, select_tables, 0)))
             {
               update_non_unique_table_error(tab, "CREATE", duplicate);
               res= 1;

sql/sql_update.cc

@@ -636,7 +636,7 @@ bool mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
   /* Check that we are not using table that we are updating in a sub select */
   {
     TABLE_LIST *duplicate;
-    if ((duplicate= unique_table(thd, table_list, table_list->next_global)))
+    if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0)))
     {
       update_non_unique_table_error(table_list, "UPDATE", duplicate);
       my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->table_name);
@@ -863,7 +863,7 @@ bool mysql_multi_update_prepare(THD *thd)
         tl->lock_type != TL_READ_NO_INSERT)
     {
       TABLE_LIST *duplicate;
-      if ((duplicate= unique_table(thd, tl, table_list)))
+      if ((duplicate= unique_table(thd, tl, table_list, 0)))
       {
         update_non_unique_table_error(table_list, "UPDATE", duplicate);
         DBUG_RETURN(TRUE);
@@ -1082,7 +1082,7 @@ static bool safe_update_on_fly(THD *thd, JOIN_TAB *join_tab,
                                List<Item> *fields)
 {
   TABLE *table= join_tab->table;
-  if (unique_table(thd, table_ref, all_tables))
+  if (unique_table(thd, table_ref, all_tables, 0))
     return 0;
   switch (join_tab->type) {
   case JT_SYSTEM: