Merge branch '10.5' into bb-10.5-release

5 files changed, 64 insertions, 14 deletions

diff --git a/sql/handler.h b/sql/handler.h
index e1f98a579b5..47bab7f75e2 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -479,6 +479,7 @@ enum chf_create_flags {
 #define HA_CREATE_TMP_ALTER     8U
 #define HA_LEX_CREATE_SEQUENCE  16U
 #define HA_VERSIONED_TABLE      32U
+#define HA_SKIP_KEY_SORT        64U
 
 #define HA_MAX_REC_LENGTH	65535
 
@@ -785,6 +786,13 @@ typedef bool Log_func(THD*, TABLE*, bool, const uchar*, const uchar*);
 */
 #define ALTER_COLUMN_INDEX_LENGTH            (1ULL << 60)
 
+/**
+  Indicate that index order might have been changed. Disables inplace algorithm
+  by default (not for InnoDB).
+*/
+#define ALTER_INDEX_ORDER                    (1ULL << 61)
+
+
 /*
   Flags set in partition_flags when altering partitions
 */
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 2967a0b42aa..e7abb51893c 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -3552,10 +3552,12 @@ String *Item_func_set_collation::val_str(String *str)
 
 bool Item_func_set_collation::fix_length_and_dec()
 {
-  if (!my_charset_same(args[0]->collation.collation, m_set_collation))
+  if (agg_arg_charsets_for_string_result(collation, args, 1))
+    return true;
+  if (!my_charset_same(collation.collation, m_set_collation))
   {
     my_error(ER_COLLATION_CHARSET_MISMATCH, MYF(0),
-             m_set_collation->name, args[0]->collation.collation->csname);
+             m_set_collation->name, collation.collation->csname);
     return TRUE;
   }
   collation.set(m_set_collation, DERIVATION_EXPLICIT,
diff --git a/sql/sql_alter.cc b/sql/sql_alter.cc
index 7901c9b5e32..8562643df97 100644
--- a/sql/sql_alter.cc
+++ b/sql/sql_alter.cc
@@ -259,7 +259,7 @@ Alter_table_ctx::Alter_table_ctx()
     db(null_clex_str), table_name(null_clex_str), alias(null_clex_str),
     new_db(null_clex_str), new_name(null_clex_str), new_alias(null_clex_str),
     fk_error_if_delete_row(false), fk_error_id(NULL),
-    fk_error_table(NULL)
+    fk_error_table(NULL), modified_primary_key(false)
 #ifdef DBUG_ASSERT_EXISTS
     , tmp_table(false)
 #endif
@@ -279,7 +279,7 @@ Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
     tables_opened(tables_opened_arg),
     new_db(*new_db_arg), new_name(*new_name_arg),
     fk_error_if_delete_row(false), fk_error_id(NULL),
-    fk_error_table(NULL)
+    fk_error_table(NULL), modified_primary_key(false)
 #ifdef DBUG_ASSERT_EXISTS
     , tmp_table(false)
 #endif
diff --git a/sql/sql_alter.h b/sql/sql_alter.h
index 89eb4ebb3e9..a499e978eef 100644
--- a/sql/sql_alter.h
+++ b/sql/sql_alter.h
@@ -324,6 +324,7 @@ public:
   const char   *fk_error_id;
   /** Name of table for the above error. */
   const char   *fk_error_table;
+  bool         modified_primary_key;
 
 private:
   char new_filename[FN_REFLEN + 1];
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 92fd6dd3ea6..b433d6b7af6 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -4435,9 +4435,30 @@ without_overlaps_err:
     my_message(ER_WRONG_AUTO_KEY, ER_THD(thd, ER_WRONG_AUTO_KEY), MYF(0));
     DBUG_RETURN(TRUE);
   }
-  /* Sort keys in optimized order */
-  my_qsort((uchar*) *key_info_buffer, *key_count, sizeof(KEY),
-	   (qsort_cmp) sort_keys);
+  /*
+    We cannot do qsort of key info if MyISAM/Aria does inplace. These engines
+    do not synchronise key info on inplace alter and that qsort is
+    indeterministic (MDEV-25803).
+
+    Yet we do not know whether we do inplace or not. That detection is done
+    after this create_table_impl() and that cannot be changed because of chicken
+    and egg problem (inplace processing requires key info made by
+    create_table_impl()).
+
+    MyISAM/Aria cannot add index inplace so we are safe to qsort key info in
+    that case. And if we don't add index then we do not need qsort at all.
+  */
+  if (!(create_info->options & HA_SKIP_KEY_SORT))
+  {
+    /*
+      Sort keys in optimized order.
+
+      Note: PK must be always first key, otherwise init_from_binary_frm_image()
+      can not understand it.
+    */
+    my_qsort((uchar*) *key_info_buffer, *key_count, sizeof(KEY),
+             (qsort_cmp) sort_keys);
+  }
   create_info->null_bits= null_fields;
 
   /* Check fields. */
@@ -8380,7 +8401,6 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
   uint used_fields, dropped_sys_vers_fields= 0;
   KEY *key_info=table->key_info;
   bool rc= TRUE;
-  bool modified_primary_key= FALSE;
   bool vers_system_invisible= false;
   Create_field *def;
   Field **f_ptr,*field;
@@ -8804,6 +8824,12 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
     if (key_info->flags & HA_INVISIBLE_KEY)
       continue;
     const char *key_name= key_info->name.str;
+    const bool primary_key= table->s->primary_key == i;
+    const bool explicit_pk= primary_key &&
+                            !my_strcasecmp(system_charset_info, key_name,
+                                           primary_key_name);
+    const bool implicit_pk= primary_key && !explicit_pk;
+
     Alter_drop *drop;
     drop_it.rewind();
     while ((drop=drop_it++))
@@ -8817,7 +8843,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       if (table->s->tmp_table == NO_TMP_TABLE)
       {
         (void) delete_statistics_for_index(thd, table, key_info, FALSE);
-        if (i == table->s->primary_key)
+        if (primary_key)
 	{
           KEY *tab_key_info= table->key_info;
 	  for (uint j=0; j < table->s->keys; j++, tab_key_info++)
@@ -8904,13 +8930,19 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       }
       if (!cfield)
       {
-        if (table->s->primary_key == i)
-          modified_primary_key= TRUE;
+        if (primary_key)
+          alter_ctx->modified_primary_key= true;
         delete_index_stat= TRUE;
         if (!(kfield->flags & VERS_SYSTEM_FIELD))
           dropped_key_part= key_part_name;
 	continue;				// Field is removed
       }
+
+      DBUG_ASSERT(!primary_key || kfield->flags & NOT_NULL_FLAG);
+      if (implicit_pk && !alter_ctx->modified_primary_key &&
+          !(cfield->flags & NOT_NULL_FLAG))
+        alter_ctx->modified_primary_key= true;
+
       key_part_length= key_part->length;
       if (cfield->field)			// Not new field
       {
@@ -8959,7 +8991,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
     {
       if (delete_index_stat) 
         (void) delete_statistics_for_index(thd, table, key_info, FALSE);
-      else if (modified_primary_key &&
+      else if (alter_ctx->modified_primary_key &&
                key_info->user_defined_key_parts != key_info->ext_key_parts)
         (void) delete_statistics_for_index(thd, table, key_info, TRUE);
     }
@@ -9003,7 +9035,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
         key_type= Key::SPATIAL;
       else if (key_info->flags & HA_NOSAME)
       {
-        if (! my_strcasecmp(system_charset_info, key_name, primary_key_name))
+        if (explicit_pk)
           key_type= Key::PRIMARY;
         else
           key_type= Key::UNIQUE;
@@ -10589,6 +10621,10 @@ do_continue:;
 
   tmp_disable_binlog(thd);
   create_info->options|=HA_CREATE_TMP_ALTER;
+  if (!(alter_info->flags & ALTER_ADD_INDEX) && !alter_ctx.modified_primary_key)
+    create_info->options|= HA_SKIP_KEY_SORT;
+  else
+    alter_info->flags|= ALTER_INDEX_ORDER;
   create_info->alias= alter_ctx.table_name;
   error= create_table_impl(thd, alter_ctx.db, alter_ctx.table_name,
                            alter_ctx.new_db, alter_ctx.tmp_name,
@@ -10625,7 +10661,7 @@ do_continue:;
     */
 
     if (!(ha_alter_info.handler_flags &
-          ~(ALTER_COLUMN_ORDER | ALTER_RENAME_COLUMN)))
+          ~(ALTER_COLUMN_ORDER | ALTER_RENAME_COLUMN | ALTER_INDEX_ORDER)))
     {
       /*
         No-op ALTER, no need to call handler API functions.
@@ -10640,6 +10676,9 @@ do_continue:;
         Also note that we ignore the LOCK clause here.
 
         TODO don't create partitioning metadata in the first place
+
+        TODO: Now case-change index name is treated as noop which is not quite
+              correct.
       */
       table->file->ha_create_partitioning_metadata(alter_ctx.get_tmp_path(),
                                                    NULL, CHF_DELETE_FLAG);