Backporting MDEV-15597 Add class Load_data_outvar and avoid using Ite…

…m::STRING_ITEM for Item_user_var_as_out_param detection

This is a part of "MDEV-18045 Backporting the MDEV-15497 changes to 10.2 branch"

mysql-test/r/loaddata.result

@@ -614,3 +614,24 @@ SELECT * FROM t1;
 a	b
 1	
 DROP TABLE t1;
+#
+# MDEV-15597 Add class Load_data_outvar and avoid using Item::STRING_ITEM for Item_user_var_as_out_param detection
+#
+SET sql_mode=NO_AUTO_VALUE_ON_ZERO;
+CREATE TABLE t1 (id integer not null auto_increment primary key);
+LOAD DATA INFILE '../../std_data/loaddata/nl.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
+Warnings:
+Warning	1261	Row 1 doesn't contain data for all columns
+SELECT * FROM t1;
+id
+0
+DROP TABLE t1;
+SET sql_mode='';
+CREATE TABLE t1 (id integer not null auto_increment primary key);
+LOAD DATA INFILE '../../std_data/loaddata/nl.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
+Warnings:
+Warning	1261	Row 1 doesn't contain data for all columns
+SELECT * FROM t1;
+id
+1
+DROP TABLE t1;

mysql-test/std_data/loaddata/nl.txt

@@ -0,0 +1 @@
+

mysql-test/t/loaddata.test

@@ -700,3 +700,19 @@ TRUNCATE TABLE t1;
 LOAD DATA INFILE '../../std_data/loaddata/mdev-15497.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
 SELECT * FROM t1;
 DROP TABLE t1;
+
+--echo #
+--echo # MDEV-15597 Add class Load_data_outvar and avoid using Item::STRING_ITEM for Item_user_var_as_out_param detection
+--echo #
+
+SET sql_mode=NO_AUTO_VALUE_ON_ZERO;
+CREATE TABLE t1 (id integer not null auto_increment primary key);
+LOAD DATA INFILE '../../std_data/loaddata/nl.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
+SELECT * FROM t1;
+DROP TABLE t1;
+
+SET sql_mode='';
+CREATE TABLE t1 (id integer not null auto_increment primary key);
+LOAD DATA INFILE '../../std_data/loaddata/nl.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
+SELECT * FROM t1;
+DROP TABLE t1;

sql/field.cc

@@ -1375,7 +1375,25 @@ bool Field::load_data_set_no_data(THD *thd, bool fixed_format)
 {
   reset();                  // Do not use the DEFAULT value
   if (fixed_format)
+  {
     set_notnull();
+    /*
+      We're loading a fixed format file, e.g.:
+        LOAD DATA INFILE 't1.txt' INTO TABLE t1 FIELDS TERMINATED BY '';
+      Suppose the file ended unexpectedly and no data was provided for an
+      auto-increment column in the current row.
+      Historically, if sql_mode=NO_AUTO_VALUE_ON_ZERO, then the column value
+      is set to 0 in such case (the next auto_increment value is not used).
+      This behaviour was introduced by the fix for "bug#12053" in mysql-4.1.
+      Note, loading a delimited file works differently:
+      "no data" is not converted to 0 on NO_AUTO_VALUE_ON_ZERO:
+      it's considered as equal to setting the column to NULL,
+      which is then replaced to the next auto_increment value.
+      This difference seems to be intentional.
+    */
+    if (this == table->next_number_field)
+      table->auto_increment_field_not_null= true;
+  }
   set_has_explicit_value(); // Do not auto-update this field
   return false;
 }

sql/item.cc

@@ -2645,6 +2645,31 @@ void Item_field::reset_field(Field *f)
 }
 
 
+void Item_field::load_data_print_for_log_event(THD *thd, String *to) const
+{
+  append_identifier(thd, to, name, (uint) strlen(name));
+}
+
+
+bool Item_field::load_data_set_no_data(THD *thd, const Load_data_param *param)
+{
+  if (field->load_data_set_no_data(thd, param->is_fixed_length()))
+    return true;
+  /*
+    TODO: We probably should not throw warning for each field.
+    But how about intention to always have the same number
+    of warnings in THD::cuted_fields (and get rid of cuted_fields
+    in the end ?)
+  */
+  thd->cuted_fields++;
+  push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                      ER_WARN_TOO_FEW_RECORDS,
+                      ER_THD(thd, ER_WARN_TOO_FEW_RECORDS),
+                      thd->get_stmt_da()->current_row_for_warning());
+  return false;
+}
+
+
 bool Item_field::enumerate_field_refs_processor(void *arg)
 {
   Field_enumerator *fe= (Field_enumerator*)arg;

sql/item.h

@@ -1866,6 +1866,20 @@ class Item: public Value_source,
   {
     return 0;
   }
+
+  virtual Load_data_outvar *get_load_data_outvar()
+  {
+    return 0;
+  }
+  Load_data_outvar *get_load_data_outvar_or_error()
+  {
+    Load_data_outvar *dst= get_load_data_outvar();
+    if (dst)
+      return dst;
+    my_error(ER_NONUPDATEABLE_COLUMN, MYF(0), name);
+    return NULL;
+  }
+
   /**
     Test whether an expression is expensive to compute. Used during
     optimization to avoid computing expensive expressions during this
@@ -2538,7 +2552,8 @@ class Item_ident_for_show :public Item
 };
 
 
-class Item_field :public Item_ident
+class Item_field :public Item_ident,
+                  public Load_data_outvar
 {
 protected:
   void set_field(Field *field);
@@ -2585,6 +2600,30 @@ class Item_field :public Item_ident
   bool val_bool_result();
   bool is_null_result();
   bool send(Protocol *protocol, String *str_arg);
+  Load_data_outvar *get_load_data_outvar()
+  {
+    return this;
+  }
+  bool load_data_set_null(THD *thd, const Load_data_param *param)
+  {
+    return field->load_data_set_null(thd);
+  }
+  bool load_data_set_value(THD *thd, const char *pos, uint length,
+                           const Load_data_param *param)
+  {
+    field->load_data_set_value(pos, length, param->charset());
+    return false;
+  }
+  bool load_data_set_no_data(THD *thd, const Load_data_param *param);
+  void load_data_print_for_log_event(THD *thd, String *to) const;
+  bool load_data_add_outvar(THD *thd, Load_data_param *param) const
+  {
+    return param->add_outvar_field(thd, field);
+  }
+  uint load_data_fixed_length() const
+  {
+    return field->field_length;
+  }
   void reset_field(Field *f);
   bool fix_fields(THD *, Item **);
   void fix_after_pullout(st_select_lex *new_parent, Item **ref, bool merge);
@@ -4379,6 +4418,10 @@ class Item_ref :public Item_ident
   void cleanup();
   Item_field *field_for_view_update()
     { return (*ref)->field_for_view_update(); }
+  Load_data_outvar *get_load_data_outvar()
+  {
+    return (*ref)->get_load_data_outvar();
+  }
   virtual Ref_Type ref_type() { return REF; }
 
   // Row emulation: forwarding of ROW-related calls to ref

sql/item_func.cc

@@ -5751,7 +5751,9 @@ my_decimal* Item_user_var_as_out_param::val_decimal(my_decimal *decimal_buffer)
 }
 
 
-void Item_user_var_as_out_param::print_for_load(THD *thd, String *str)
+void Item_user_var_as_out_param::load_data_print_for_log_event(THD *thd,
+                                                               String *str)
+                                                               const
 {
   str->append('@');
   append_identifier(thd, str, name.str, name.length);

sql/item_func.h

@@ -2038,13 +2038,43 @@ class Item_func_get_user_var :public Item_func_user_var,
   in List<Item> and desire to place this code somewhere near other functions
   working with user variables.
 */
-class Item_user_var_as_out_param :public Item
+class Item_user_var_as_out_param :public Item,
+                                  public Load_data_outvar
 {
   LEX_STRING name;
   user_var_entry *entry;
 public:
   Item_user_var_as_out_param(THD *thd, LEX_STRING a): Item(thd), name(a)
   { set_name(thd, a.str, 0, system_charset_info); }
+  Load_data_outvar *get_load_data_outvar()
+  {
+    return this;
+  }
+  bool load_data_set_null(THD *thd, const Load_data_param *param)
+  {
+    set_null_value(param->charset());
+    return false;
+  }
+  bool load_data_set_no_data(THD *thd, const Load_data_param *param)
+  {
+    set_null_value(param->charset());
+    return false;
+  }
+  bool load_data_set_value(THD *thd, const char *pos, uint length,
+                           const Load_data_param *param)
+  {
+    set_value(pos, length, param->charset());
+    return false;
+  }
+  void load_data_print_for_log_event(THD *thd, String *to) const;
+  bool load_data_add_outvar(THD *thd, Load_data_param *param) const
+  {
+    return param->add_outvar_user_var(thd);
+  }
+  uint load_data_fixed_length() const
+  {
+    return 0;
+  }
   /* We should return something different from FIELD_ITEM here */
   enum Type type() const { return STRING_ITEM;}
   double val_real();
@@ -2053,7 +2083,6 @@ class Item_user_var_as_out_param :public Item
   my_decimal *val_decimal(my_decimal *decimal_buffer);
   /* fix_fields() binds variable name with its entry structure */
   bool fix_fields(THD *thd, Item **ref);
-  void print_for_load(THD *thd, String *str);
   void set_null_value(CHARSET_INFO* cs);
   void set_value(const char *str, uint length, CHARSET_INFO* cs);
   enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }