Fixed unique prefix key bug for multibyte character sets (BUG #4521) for

InnoDB. This fixes also a second part of the same problem with prefix keys
on a multibyte string column for InnoDB.


innobase/btr/btr0btr.c:
  Multibyte character set prefix indexes are not any more fixed size. Therefore,
  we have to chect that length of the index field in not greater than
  prefix length.
innobase/rem/rem0cmp.c:
  Remove unnecessary changes.
innobase/row/row0ins.c:
  Fixed unique prefix key or prefix key using multibyte character set bugs for
  InnoDB (BUG #4521). For prefix keys we have to get the storage length
  for the prefix length of characters in the key.
innobase/row/row0row.c:
  Fixed unique prefix key or prefix key using multibyte character set bugs for
  InnoDB (BUG #4521). For prefix keys we have to get the storage length
  for the prefix length of characters in the key.
innobase/row/row0sel.c:
  Fixed unique prefix key or prefix key using multibyte character set bugs for
  InnoDB (BUG #4521). For prefix keys we have to get the storage length
  for the prefix length of characters in the key.
innobase/row/row0upd.c:
  Fixed unique prefix key or prefix key using multibyte character set bugs for
  InnoDB (BUG #4521). For prefix keys we have to get the storage length
  for the prefix length of characters in the key.
mysql-test/r/ctype_utf8.result:
  Added utf8 character test cases for InnoDB.
mysql-test/t/ctype_utf8.test:
  Added utf8 character expected test results for InnoDB.
sql/ha_innodb.cc:
  Added function innobase_get_at_most_n_mbchars to return position of
  the nth character in the multibyte character string.
sql/ha_innodb.h:
  Remove unnecessary changes.

1 files changed, 13 insertions, 4 deletions

diff --git a/innobase/row/row0ins.c b/innobase/row/row0ins.c
index edd3099b5f3..2429b8f2bf3 100644
--- a/innobase/row/row0ins.c
+++ b/innobase/row/row0ins.c
@@ -1999,6 +1999,7 @@ row_ins_index_entry_set_vals(
 	dfield_t*	row_field;
 	ulint		n_fields;
 	ulint		i;
+	dtype_t*        cur_type;
 
 	ut_ad(entry && row);
 
@@ -2012,10 +2013,18 @@ row_ins_index_entry_set_vals(
 
 		/* Check column prefix indexes */
 		if (ind_field->prefix_len > 0
-		    && dfield_get_len(row_field) != UNIV_SQL_NULL
-		    && dfield_get_len(row_field) > ind_field->prefix_len) {
-		    
-		        field->len = ind_field->prefix_len;
+		    && dfield_get_len(row_field) != UNIV_SQL_NULL) {
+
+			/* For prefix keys get the storage length
+			for the prefix_len characters. */
+
+			cur_type = dict_col_get_type(
+				dict_field_get_col(ind_field));
+
+			field->len = innobase_get_at_most_n_mbchars(
+				dtype_get_charset_coll(cur_type->prtype),
+				ind_field->prefix_len,
+				dfield_get_len(field),row_field->data);
 		} else {
 		        field->len = row_field->len;
 		}