Merge 10.3 into 10.4

sql/item_subselect.cc

@@ -683,6 +683,31 @@ bool Item_subselect::is_expensive()
 }
 
 
+static
+int walk_items_for_table_list(Item_processor processor,
+                              bool walk_subquery, void *argument,
+                              List<TABLE_LIST>& join_list)
+{
+  List_iterator<TABLE_LIST> li(join_list);
+  int res;
+  while (TABLE_LIST *table= li++)
+  {
+    if (table->on_expr)
+    {
+      if ((res= table->on_expr->walk(processor, walk_subquery, argument)))
+        return res;
+    }
+    if (table->nested_join)
+    {
+      if ((res= walk_items_for_table_list(processor, walk_subquery, argument,
+                                          table->nested_join->join_list)))
+        return res;
+    }
+  }
+  return 0;
+}
+
+
 bool Item_subselect::walk(Item_processor processor, bool walk_subquery,
                           void *argument)
 {
@@ -714,7 +739,10 @@ bool Item_subselect::walk(Item_processor processor, bool walk_subquery,
       if (lex->having && (lex->having)->walk(processor, walk_subquery,
                                              argument))
         return 1;
-      /* TODO: why does this walk WHERE/HAVING but not ON expressions of outer joins? */
+
+     if (walk_items_for_table_list(processor, walk_subquery, argument,
+                                       *lex->join_list))
+        return 1;
 
       while ((item=li++))
       {

sql/mf_iocache.cc

@@ -26,7 +26,7 @@
   Used instead of FILE when reading or writing whole files.
   This will make mf_rec_cache obsolete.
   One can change info->pos_in_file to a higher value to skip bytes in file if
-  also info->rc_pos is set to info->rc_end.
+  also info->read_pos is set to info->read_end.
   If called through open_cached_file(), then the temporary file will
   only be created if a write exeeds the file buffer or if one calls
   flush_io_cache().  

sql/signal_handler.cc

@@ -32,7 +32,7 @@
 #endif
 
 
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(__FreeBSD__)
 #include <sys/sysctl.h>
 #endif
 
@@ -57,7 +57,7 @@ extern const char *optimizer_switch_names[];
 static inline void output_core_info()
 {
   /* proc is optional on some BSDs so it can't hurt to look */
-#if defined(HAVE_READLINK) && !defined(__APPLE__)
+#if defined(HAVE_READLINK) && !defined(__APPLE__) && !defined(__FreeBSD__)
   char buff[PATH_MAX];
   ssize_t len;
   int fd;
@@ -83,7 +83,7 @@ static inline void output_core_info()
     my_close(fd, MYF(0));
   }
 #endif
-#elif defined(__APPLE__)
+#elif defined(__APPLE__) || defined(__FreeBSD__)
   char buff[PATH_MAX];
   size_t len = sizeof(buff);
   if (sysctlbyname("kern.corefile", buff, &len, NULL, 0) == 0)

sql/sql_derived.cc

@@ -1,6 +1,6 @@
 /*
    Copyright (c) 2002, 2011, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2020, MariaDB
+   Copyright (c) 2010, 2021, MariaDB
 
    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
@@ -596,6 +596,32 @@ bool mysql_derived_init(THD *thd, LEX *lex, TABLE_LIST *derived)
 }
 
 
+/**
+  @brief
+    Prevent name resolution out of context of ON expressions in derived tables
+
+  @param
+    join_list  list of tables used in from list of a derived
+
+  @details
+    The function sets the Name_resolution_context::outer_context to NULL
+    for all ON expressions contexts in the given join list. It does this
+    recursively for all nested joins the list contains.
+*/
+
+static void nullify_outer_context_for_on_clauses(List<TABLE_LIST>& join_list)
+{
+  List_iterator<TABLE_LIST> li(join_list);
+  while (TABLE_LIST *table= li++)
+  {
+    if (table->on_context)
+      table->on_context->outer_context= NULL;
+    if (table->nested_join)
+      nullify_outer_context_for_on_clauses(table->nested_join->join_list);
+  }
+}
+
+
 /*
   Create temporary table structure (but do not fill it)
 
@@ -760,7 +786,12 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
   /* prevent name resolving out of derived table */
   for (SELECT_LEX *sl= first_select; sl; sl= sl->next_select())
   {
+    // Prevent it for the WHERE clause
     sl->context.outer_context= 0;
+
+    // And for ON clauses, if there are any
+    nullify_outer_context_for_on_clauses(*sl->join_list);
+
     if (!derived->is_with_table_recursive_reference() ||
         (!derived->with->with_anchor && 
          !derived->with->is_with_prepared_anchor()))

sql/sql_lex.cc

@@ -9392,7 +9392,7 @@ SELECT_LEX *LEX::parsed_subselect(SELECT_LEX_UNIT *unit)
               (curr_sel == NULL && current_select == &builtin_select));
   if (curr_sel)
   {
-    curr_sel->register_unit(unit, &curr_sel->context);
+    curr_sel->register_unit(unit, context_stack.head());
     curr_sel->add_statistics(unit);
   }
 

sql/sql_parse.cc

@@ -7607,6 +7607,7 @@ mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *select_lex)
   bool new_select= select_lex == NULL;
   int old_nest_level= lex->current_select->nest_level;
   DBUG_ENTER("mysql_new_select");
+  Name_resolution_context *curr_context;
 
   if (new_select)
   {
@@ -7614,6 +7615,7 @@ mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *select_lex)
       DBUG_RETURN(1);
     select_lex->select_number= ++thd->lex->stmt_lex->current_select_number;
     select_lex->parent_lex= lex; /* Used in init_query. */
+    curr_context= lex->context_stack.head();
     select_lex->init_query();
     select_lex->init_select();
   }
@@ -7635,7 +7637,8 @@ mysql_new_select(LEX *lex, bool move_down, SELECT_LEX *select_lex)
       By default we assume that it is usual subselect and we have outer name
       resolution context, if no we will assign it to 0 later
     */
-    select_lex->context.outer_context= &select_lex->outer_select()->context;
+
+    select_lex->context.outer_context= curr_context;
   }
   else
   {

sql/sql_table.cc

@@ -1,6 +1,6 @@
 /*
    Copyright (c) 2000, 2019, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2020, MariaDB
+   Copyright (c) 2010, 2021, MariaDB
 
    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
@@ -8318,7 +8318,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
          def->real_field_type() == MYSQL_TYPE_NEWDATE ||
          def->real_field_type() == MYSQL_TYPE_DATETIME ||
          def->real_field_type() == MYSQL_TYPE_DATETIME2) &&
-         !alter_ctx->datetime_field &&
+         !alter_ctx->datetime_field && !def->field &&
          !(~def->flags & (NO_DEFAULT_VALUE_FLAG | NOT_NULL_FLAG)) &&
          thd->variables.sql_mode & MODE_NO_ZERO_DATE)
     {
@@ -8527,7 +8527,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       key_parts.push_back(new (thd->mem_root) Key_part_spec(&cfield->field_name,
                                                             key_part_length, true),
                           thd->mem_root);
-      if (cfield->invisible < INVISIBLE_SYSTEM)
+      if (!(cfield->invisible == INVISIBLE_SYSTEM && cfield->vers_sys_field()))
         user_keyparts= true;
     }
     if (table->s->tmp_table == NO_TMP_TABLE)
@@ -8539,6 +8539,14 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
         (void) delete_statistics_for_index(thd, table, key_info, TRUE);
     }
 
+    if (!user_keyparts && key_parts.elements)
+    {
+      /*
+        If we dropped all user key-parts we also drop implicit system fields.
+      */
+      key_parts.empty();
+    }
+
     if (key_parts.elements)
     {
       KEY_CREATE_INFO key_create_info;
@@ -8574,7 +8582,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
           key_type= Key::PRIMARY;
         else
           key_type= Key::UNIQUE;
-        if (dropped_key_part && user_keyparts)
+        if (dropped_key_part)
         {
           my_error(ER_KEY_COLUMN_DOES_NOT_EXITS, MYF(0), dropped_key_part);
           if (long_hash_key)