MDEV-26841: ROW_NUMBER is not set and differs from the message upon

ER_WRONG_VALUE_COUNT_ON_ROW for the 1st row

Analysis: Current row for warning does not increment for prepare phase
Fix: Increment current row for warning if number of fields in the table and
row values dont match and number of values in rows is greater than number
of fields

mysql-test/main/get_diagnostics.result

@@ -1747,3 +1747,21 @@ SELECT @n, @m;
 @n	@m
 2	Data truncated for column 'a' at row 2
 DROP TABLE t1;
+#
+# MDEV-26841: ROW_NUMBER is not set and differs from the message upon
+# ER_WRONG_VALUE_COUNT_ON_ROW for the 1st row
+#
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1,2),(3);
+ERROR 21S01: Column count doesn't match value count at row 1
+GET DIAGNOSTICS CONDITION 1 @n= ROW_NUMBER, @m= MESSAGE_TEXT;
+SELECT @n, @m;
+@n	@m
+1	Column count doesn't match value count at row 1
+INSERT INTO t1(a) VALUES(1,2), (3);
+ERROR 21S01: Column count doesn't match value count at row 1
+GET DIAGNOSTICS CONDITION 1 @n= ROW_NUMBER, @m= MESSAGE_TEXT;
+SELECT @n, @m;
+@n	@m
+1	Column count doesn't match value count at row 1
+DROP TABLE t1;

mysql-test/main/get_diagnostics.test

@@ -1632,3 +1632,24 @@ GET DIAGNOSTICS CONDITION 1 @n= ROW_NUMBER, @m= MESSAGE_TEXT;
 SELECT @n, @m;
 
 DROP TABLE t1;
+
+--echo #
+--echo # MDEV-26841: ROW_NUMBER is not set and differs from the message upon
+--echo # ER_WRONG_VALUE_COUNT_ON_ROW for the 1st row
+--echo #
+
+CREATE TABLE t1 (a INT);
+
+--error ER_WRONG_VALUE_COUNT_ON_ROW
+INSERT INTO t1 VALUES (1,2),(3);
+
+GET DIAGNOSTICS CONDITION 1 @n= ROW_NUMBER, @m= MESSAGE_TEXT;
+SELECT @n, @m;
+
+--error ER_WRONG_VALUE_COUNT_ON_ROW
+INSERT INTO t1(a) VALUES(1,2), (3);
+
+GET DIAGNOSTICS CONDITION 1 @n= ROW_NUMBER, @m= MESSAGE_TEXT;
+SELECT @n, @m;
+
+DROP TABLE t1;

sql/sql_insert.cc

@@ -229,6 +229,7 @@ static int check_insert_fields(THD *thd, TABLE_LIST *table_list,
     }
     if (values.elements != table->s->visible_fields)
     {
+      thd->get_stmt_da()->reset_current_row_for_warning(1);
       my_error(ER_WRONG_VALUE_COUNT_ON_ROW, MYF(0), 1L);
       DBUG_RETURN(-1);
     }
@@ -253,6 +254,7 @@ static int check_insert_fields(THD *thd, TABLE_LIST *table_list,
 
     if (fields.elements != values.elements)
     {
+      thd->get_stmt_da()->reset_current_row_for_warning(1);
       my_error(ER_WRONG_VALUE_COUNT_ON_ROW, MYF(0), 1L);
       DBUG_RETURN(-1);
     }