1 files changed, 48 insertions, 59 deletions

diff --git a/sql/table.cc b/sql/table.cc
index a8eeeb53d72..b8ed7a99156 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -46,6 +46,10 @@
 #include "sql_show.h"
 #include "opt_trace.h"
 #include "sql_db.h"              // get_default_db_collation
+#include "sql_update.h"          // class Sql_cmd_update
+#include "sql_delete.h"          // class Sql_cmd_delete
+
+
 
 /* For MySQL 5.7 virtual fields */
 #define MYSQL57_GENERATED_FIELD 128
@@ -942,39 +946,6 @@ static uint enum_value_with_check(THD *thd, TABLE_SHARE *share,
 }
 
 
-/**
-   Check if a collation has changed number
-
-   @param mysql_version
-   @param current collation number
-
-   @retval new collation number (same as current collation number of no change)
-*/
-
-static uint upgrade_collation(ulong mysql_version, uint cs_number)
-{
-  if (mysql_version >= 50300 && mysql_version <= 50399)
-  {
-    switch (cs_number) {
-    case 149: return MY_PAGE2_COLLATION_ID_UCS2;   // ucs2_crotian_ci
-    case 213: return MY_PAGE2_COLLATION_ID_UTF8;   // utf8_crotian_ci
-    }
-  }
-  if ((mysql_version >= 50500 && mysql_version <= 50599) ||
-      (mysql_version >= 100000 && mysql_version <= 100005))
-  {
-    switch (cs_number) {
-    case 149: return MY_PAGE2_COLLATION_ID_UCS2;   // ucs2_crotian_ci
-    case 213: return MY_PAGE2_COLLATION_ID_UTF8;   // utf8_crotian_ci
-    case 214: return MY_PAGE2_COLLATION_ID_UTF32;  // utf32_croatian_ci
-    case 215: return MY_PAGE2_COLLATION_ID_UTF16;  // utf16_croatian_ci
-    case 245: return MY_PAGE2_COLLATION_ID_UTF8MB4;// utf8mb4_croatian_ci
-    }
-  }
-  return cs_number;
-}
-
-
 void Column_definition_attributes::frm_pack_basic(uchar *buff) const
 {
   int2store(buff + 3, length);
@@ -1034,7 +1005,7 @@ bool Column_definition_attributes::frm_unpack_charset(TABLE_SHARE *share,
                                                       const uchar *buff)
 {
   uint cs_org= buff[14] + (((uint) buff[11]) << 8);
-  uint cs_new= upgrade_collation(share->mysql_version, cs_org);
+  uint cs_new= Charset::upgrade_collation_id(share->mysql_version, cs_org);
   if (cs_org != cs_new)
     share->incompatible_version|= HA_CREATE_USED_CHARSET;
   if (cs_new && !(charset= get_charset(cs_new, MYF(0))))
@@ -1894,7 +1865,7 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
   if (!frm_image[32])				// New frm file in 3.23
   {
     uint cs_org= (((uint) frm_image[41]) << 8) + (uint) frm_image[38];
-    uint cs_new= upgrade_collation(share->mysql_version, cs_org);
+    uint cs_new= Charset::upgrade_collation_id(share->mysql_version, cs_org);
     if (cs_org != cs_new)
       share->incompatible_version|= HA_CREATE_USED_CHARSET;
 
@@ -3110,6 +3081,9 @@ int TABLE_SHARE::init_from_binary_frm_image(THD *thd, bool write,
           goto err;
 
         field= key_part->field= share->field[key_part->fieldnr-1];
+        if (Charset::collation_changed_order(share->mysql_version,
+                                             field->charset()->number))
+          share->incompatible_version|= HA_CREATE_USED_CHARSET;
         key_part->type= field->key_type();
 
         if (field->invisible > INVISIBLE_USER && !field->vers_sys_field())
@@ -3572,7 +3546,6 @@ int TABLE_SHARE::init_from_sql_statement_string(THD *thd, bool write,
   char *sql_copy;
   handler *file;
   LEX *old_lex;
-  Query_arena *arena, backup;
   LEX tmp_lex;
   KEY *unused1;
   uint unused2;
@@ -3599,11 +3572,6 @@ int TABLE_SHARE::init_from_sql_statement_string(THD *thd, bool write,
   old_lex= thd->lex;
   thd->lex= &tmp_lex;
 
-  arena= thd->stmt_arena;
-  if (arena->is_conventional())
-    arena= 0;
-  else
-    thd->set_n_backup_active_arena(arena, &backup);
 
   /*
     THD::reset_db() does not set THD::db_charset,
@@ -3655,8 +3623,6 @@ ret:
   lex_end(thd->lex);
   thd->reset_db(&db_backup);
   thd->lex= old_lex;
-  if (arena)
-    thd->restore_active_arena(arena, &backup);
   reenable_binlog(thd);
   thd->variables.character_set_client= old_cs;
   if (unlikely(thd->is_error() || error))
@@ -6886,6 +6852,9 @@ bool TABLE_LIST::prepare_security(THD *thd)
 #ifndef DBUG_OFF
 void TABLE_LIST::set_check_merged()
 {
+  if (is_view())
+    return;
+
   DBUG_ASSERT(derived);
   /*
     It is not simple to check all, but at least this should be checked:
@@ -6903,7 +6872,7 @@ void TABLE_LIST::set_check_materialized()
   DBUG_ENTER("TABLE_LIST::set_check_materialized");
   SELECT_LEX_UNIT *derived= this->derived;
   if (view)
-    derived= &view->unit;
+    derived= this->derived= &view->unit;
   DBUG_ASSERT(derived);
   DBUG_ASSERT(!derived->is_excluded());
   if (!derived->first_select()->exclude_from_table_unique_test)
@@ -7213,10 +7182,9 @@ void Field_iterator_table_ref::set_field_iterator()
                        table_ref->alias.str));
   }
   /* This is a merge view, so use field_translation. */
-  else if (table_ref->field_translation &&
-           !table_ref->is_materialized_derived())
+  else if (!table_ref->is_materialized_derived() &&
+           table_ref->is_merged_derived() && table_ref->field_translation)
   {
-    DBUG_ASSERT(table_ref->is_merged_derived());
     field_it= &view_field_it;
     DBUG_PRINT("info", ("field_it for '%s' is Field_iterator_view",
                         table_ref->alias.str));
@@ -9303,7 +9271,7 @@ bool TABLE::check_period_overlaps(const KEY &key,
         return false;
     uint kp_len= key.key_part[part_nr].length;
     if (f->cmp_prefix(f->ptr_in_record(lhs), f->ptr_in_record(rhs),
-                      kp_len) != 0)
+                      kp_len / f->charset()->mbmaxlen) != 0)
       return false;
   }
 
@@ -9722,8 +9690,13 @@ void TABLE_LIST::wrap_into_nested_join(List<TABLE_LIST> &join_list)
 
 static inline bool derived_table_optimization_done(TABLE_LIST *table)
 {
-  return table->derived &&
-      (table->derived->is_excluded() ||
+  SELECT_LEX_UNIT *derived= (table->derived ?
+                             table->derived :
+                             (table->view ?
+                              &table->view->unit:
+                              NULL));
+  return derived &&
+      (derived->is_excluded() ||
        table->is_materialized_derived());
 }
 
@@ -9785,20 +9758,36 @@ bool TABLE_LIST::init_derived(THD *thd, bool init_view)
     set_derived();
   }
 
-  if (!is_view() &&
-      !derived_table_optimization_done(this))
+  if (!derived_table_optimization_done(this))
   {
     /* A subquery might be forced to be materialized due to a side-effect. */
-    bool forced_no_merge_for_update_delete=
-           belong_to_view ? belong_to_view->updating :
-                           !unit->outer_select()->outer_select();
-    if (!is_materialized_derived() && first_select->is_mergeable() &&
-        (unit->outer_select() && !unit->outer_select()->with_rownum) &&
+    if (!is_materialized_derived() && unit->can_be_merged() &&
+        /*
+          Following is special case of
+          SELECT * FROM (<limited-select>) WHERE ROWNUM() <= nnn
+        */
+        (unit->outer_select() &&
+         !(unit->outer_select()->with_rownum &&
+           unit->outer_select()->table_list.elements == 1 &&
+           (thd->lex->sql_command == SQLCOM_SELECT ||
+            !unit->outer_select()->is_query_topmost(thd)) &&
+           !is_view())) &&
+
         (!thd->lex->with_rownum ||
          (!first_select->group_list.elements &&
           !first_select->order_list.elements)) &&
-        optimizer_flag(thd, OPTIMIZER_SWITCH_DERIVED_MERGE) &&
-        !thd->lex->can_not_use_merged(forced_no_merge_for_update_delete) &&
+        (is_view() ||
+         optimizer_flag(thd, OPTIMIZER_SWITCH_DERIVED_MERGE)) &&
+          !thd->lex->can_not_use_merged() &&
+        !(!is_view() &&
+          (thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
+           thd->lex->sql_command == SQLCOM_DELETE_MULTI ||
+           (thd->lex->sql_command == SQLCOM_UPDATE &&
+            (((Sql_cmd_update *) thd->lex->m_sql_cmd)->is_multitable() ||
+             thd->lex->query_tables->is_multitable())) ||
+           (thd->lex->sql_command == SQLCOM_DELETE &&
+            (((Sql_cmd_delete *) thd->lex->m_sql_cmd)->is_multitable() ||
+             thd->lex->query_tables->is_multitable())))) &&
         !is_recursive_with_table())
       set_merged_derived();
     else