Merge 10.5 into 10.6

12 files changed, 104 insertions, 52 deletions

diff --git a/sql/field.h b/sql/field.h
index 0b8f317b5b8..7be16a1457e 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -517,6 +517,7 @@ enum enum_vcol_info_type
 {
   VCOL_GENERATED_VIRTUAL, VCOL_GENERATED_STORED,
   VCOL_DEFAULT, VCOL_CHECK_FIELD, VCOL_CHECK_TABLE,
+  VCOL_USING_HASH,
   /* Additional types should be added here */
   /* Following is the highest value last   */
   VCOL_TYPE_NONE = 127 // Since the 0 value is already in use
@@ -534,6 +535,8 @@ static inline const char *vcol_type_name(enum_vcol_info_type type)
   case VCOL_CHECK_FIELD:
   case VCOL_CHECK_TABLE:
     return "CHECK";
+  case VCOL_USING_HASH:
+    return "USING HASH";
   case VCOL_TYPE_NONE:
     return "UNTYPED";
   }
diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc
index 1aa917d525b..f6c4b95dcbd 100644
--- a/sql/ha_partition.cc
+++ b/sql/ha_partition.cc
@@ -1203,7 +1203,6 @@ static const LEX_CSTRING opt_op_name[]=
 };
 
 
-static const LEX_CSTRING msg_note= { STRING_WITH_LEN("note") };
 static const LEX_CSTRING msg_warning= { STRING_WITH_LEN("warning") };
 #define msg_error error_clex_str
 
@@ -11068,11 +11067,8 @@ int ha_partition::check_misplaced_rows(uint read_part_id, bool do_repair)
       read_part_id != m_part_info->vers_info->now_part->id &&
       !m_part_info->vers_info->interval.is_set())
   {
-    print_admin_msg(ha_thd(), MYSQL_ERRMSG_SIZE, &msg_note,
-                    table_share->db.str, table->alias,
-                    &opt_op_name[CHECK_PARTS],
-                    "Not supported for non-INTERVAL history partitions");
-    DBUG_RETURN(HA_ADMIN_NOT_IMPLEMENTED);
+    /* Skip this check as it is not supported for non-INTERVAL history partitions. */
+    DBUG_RETURN(HA_ADMIN_OK);
   }
 
   if (do_repair)
diff --git a/sql/handler.cc b/sql/handler.cc
index e4543bde5de..9fc9399d521 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -8285,15 +8285,16 @@ bool Table_scope_and_contents_source_st::vers_fix_system_fields(
   if (!vers_info.need_check(alter_info))
     return false;
 
-  if (!vers_info.versioned_fields && vers_info.unversioned_fields &&
-      !(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING))
+  const bool add_versioning= alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING;
+
+  if (!vers_info.versioned_fields && vers_info.unversioned_fields && !add_versioning)
   {
     // All is correct but this table is not versioned.
     options&= ~HA_VERSIONED_TABLE;
     return false;
   }
 
-  if (!(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING) && vers_info)
+  if (!add_versioning && vers_info && !vers_info.versioned_fields)
   {
     my_error(ER_MISSING, MYF(0), create_table.table_name.str,
              "WITH SYSTEM VERSIONING");
@@ -8303,8 +8304,7 @@ bool Table_scope_and_contents_source_st::vers_fix_system_fields(
   List_iterator<Create_field> it(alter_info->create_list);
   while (Create_field *f= it++)
   {
-    if ((f->versioning == Column_definition::VERSIONING_NOT_SET &&
-         !(alter_info->flags & ALTER_ADD_SYSTEM_VERSIONING)) ||
+    if ((f->versioning == Column_definition::VERSIONING_NOT_SET && !add_versioning) ||
         f->versioning == Column_definition::WITHOUT_VERSIONING)
     {
       f->flags|= VERS_UPDATE_UNVERSIONED_FLAG;
diff --git a/sql/handler.h b/sql/handler.h
index 0cdaf1dd698..5fe06ecd0bc 100644
--- a/sql/handler.h
+++ b/sql/handler.h
@@ -483,6 +483,7 @@ 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
 
@@ -789,11 +790,16 @@ 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)
 
 /**
   Means that the ignorability of an index is changed.
 */
-#define ALTER_INDEX_IGNORABILITY              (1ULL << 61)
+#define ALTER_INDEX_IGNORABILITY              (1ULL << 62)
 
 /*
   Flags set in partition_flags when altering partitions
diff --git a/sql/item.h b/sql/item.h
index 6b9223de122..468b9932f02 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -7696,6 +7696,19 @@ public:
 
 
 /*
+  fix_escape_item() sets the out "escape" parameter to:
+  - native code in case of an 8bit character set
+  - Unicode code point in case of a multi-byte character set
+
+  The value meaning a not-initialized ESCAPE character must not be equal to
+  any valid value, so must be outside of these ranges:
+  - -128..+127, not to conflict with a valid 8bit charcter
+  - 0..0x10FFFF, not to conflict with a valid Unicode code point
+  The exact value does not matter.
+*/
+#define ESCAPE_NOT_INITIALIZED -1000
+
+/*
   It's used in ::fix_fields() methods of LIKE and JSON_SEARCH
   functions to handle the ESCAPE parameter.
   This parameter is quite non-standard so the specific function.
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 227e65c9d94..5f21da17d8b 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -5607,7 +5607,7 @@ void Item_func_like::print(String *str, enum_query_type query_type)
 longlong Item_func_like::val_int()
 {
   DBUG_ASSERT(fixed());
-  DBUG_ASSERT(escape != -1);
+  DBUG_ASSERT(escape != ESCAPE_NOT_INITIALIZED);
   String* res= args[0]->val_str(&cmp_value1);
   if (args[0]->null_value)
   {
@@ -5711,7 +5711,7 @@ bool fix_escape_item(THD *thd, Item *escape_item, String *tmp_str,
     return TRUE;
   }
 
-  IF_DBUG(*escape= -1,);
+  IF_DBUG(*escape= ESCAPE_NOT_INITIALIZED,);
 
   if (escape_item->const_item())
   {
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 9399a566715..eb9c59d31f7 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -1,6 +1,6 @@
 /*
    Copyright (c) 2000, 2017, Oracle and/or its affiliates.
-   Copyright (c) 2009, 2020, MariaDB Corporation.
+   Copyright (c) 2009, 2021, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -3579,11 +3579,13 @@ 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->coll_name.str,
-             args[0]->collation.collation->cs_name.str);
+             collation.collation->cs_name.str);
     return TRUE;
   }
   collation.set(m_set_collation, DERIVATION_EXPLICIT,
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index efdc3c8dcae..1ab3cbad4af 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -8524,7 +8524,6 @@ static int get_options(int *argc_ptr, char ***argv_ptr)
   {
     /* Allow break with SIGINT, no core or stack trace */
     test_flags|= TEST_SIGINT;
-    opt_stack_trace= 1;
     test_flags&= ~TEST_CORE_ON_SIGNAL;
   }
   /* Set global MyISAM variables from delay_key_write_options */
diff --git a/sql/sql_alter.cc b/sql/sql_alter.cc
index 5827b7b104b..3d2884e8d85 100644
--- a/sql/sql_alter.cc
+++ b/sql/sql_alter.cc
@@ -254,16 +254,8 @@ Alter_info::algorithm(const THD *thd) const
 
 
 Alter_table_ctx::Alter_table_ctx()
-  : implicit_default_value_error_field(NULL),
-    error_if_not_empty(false),
-    tables_opened(0),
-    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)
-#ifdef DBUG_ASSERT_EXISTS
-    , tmp_table(false)
-#endif
+  : 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)
 {
 }
 
@@ -276,12 +268,8 @@ Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
                                  uint tables_opened_arg,
                                  const LEX_CSTRING *new_db_arg,
                                  const LEX_CSTRING *new_name_arg)
-  : implicit_default_value_error_field(NULL), error_if_not_empty(false),
-    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),
-    tmp_table(false)
+  : tables_opened(tables_opened_arg),
+    new_db(*new_db_arg), new_name(*new_name_arg)
 {
   /*
     Assign members db, table_name, new_db and new_name
diff --git a/sql/sql_alter.h b/sql/sql_alter.h
index a0f89c28d2a..d91984d4b26 100644
--- a/sql/sql_alter.h
+++ b/sql/sql_alter.h
@@ -1,5 +1,5 @@
 /* Copyright (c) 2010, 2014, Oracle and/or its affiliates.
-   Copyright (c) 2013, 2020, MariaDB Corporation.
+   Copyright (c) 2013, 2021, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -313,9 +313,9 @@ public:
 
   void report_implicit_default_value_error(THD *thd, const TABLE_SHARE *) const;
 public:
-  Create_field *implicit_default_value_error_field;
-  bool         error_if_not_empty;
-  uint         tables_opened;
+  Create_field *implicit_default_value_error_field= nullptr;
+  bool         error_if_not_empty= false;
+  uint         tables_opened= 0;
   LEX_CSTRING  db;
   LEX_CSTRING  table_name;
   LEX_CSTRING  storage_engine_name;
@@ -337,13 +337,14 @@ public:
     of table to the new version ER_FK_CANNOT_DELETE_PARENT error should be
     emitted.
   */
-  bool         fk_error_if_delete_row;
+  bool fk_error_if_delete_row= false;
   /** Name of foreign key for the above error. */
-  const char   *fk_error_id;
+  const char *fk_error_id= nullptr;
   /** Name of table for the above error. */
-  const char   *fk_error_table;
+  const char *fk_error_table= nullptr;
+  bool modified_primary_key= false;
   /** Indicates that we are altering temporary table */
-  bool tmp_table;
+  bool tmp_table= false;
 
 private:
   char new_filename[FN_REFLEN + 1];
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 9b5c939ce95..6ab73458755 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -3452,9 +3452,30 @@ 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. */
@@ -7668,7 +7689,6 @@ 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;
@@ -8092,6 +8112,12 @@ 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.str);
+    const bool implicit_pk= primary_key && !explicit_pk;
+
     Alter_drop *drop;
     drop_it.rewind();
     while ((drop=drop_it++))
@@ -8105,7 +8131,7 @@ 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++)
@@ -8204,13 +8230,19 @@ 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
       {
@@ -8259,7 +8291,7 @@ 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);
     }
@@ -8304,7 +8336,7 @@ 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.str))
+        if (explicit_pk)
           key_type= Key::PRIMARY;
         else
           key_type= Key::UNIQUE;
@@ -10037,6 +10069,10 @@ 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;
   /*
     Create the .frm file for the new table. Storage engine table will not be
@@ -10095,7 +10131,7 @@ 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.
@@ -10110,6 +10146,9 @@ 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);
diff --git a/sql/table.cc b/sql/table.cc
index 0204250f650..5a622f9dbfa 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -1119,6 +1119,8 @@ static void mysql57_calculate_null_position(TABLE_SHARE *share,
   }
 }
 
+static bool fix_and_check_vcol_expr(THD *thd, TABLE *table,
+                                    Virtual_column_info *vcol);
 
 /** Parse TABLE_SHARE::vcol_defs
 
@@ -1304,6 +1306,9 @@ bool parse_vcol_defs(THD *thd, MEM_ROOT *mem_root, TABLE *table,
       Virtual_column_info *v= new (mem_root) Virtual_column_info();
       field->vcol_info= v;
       field->vcol_info->expr= hash_item;
+      field->vcol_info->set_vcol_type(VCOL_USING_HASH);
+      if (fix_and_check_vcol_expr(thd, table, v))
+        goto end;
       key->user_defined_key_parts= key->ext_key_parts= key->usable_key_parts= 1;
       key->key_part+= parts;