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.

6 files changed, 86 insertions, 54 deletions

diff --git a/innobase/btr/btr0btr.c b/innobase/btr/btr0btr.c
index 27d798f925a..e31aadbbfff 100644
--- a/innobase/btr/btr0btr.c
+++ b/innobase/btr/btr0btr.c
@@ -2400,14 +2400,17 @@ btr_index_rec_validate(
 		dtype_t*	type = dict_index_get_nth_type(index, i);
 
 		rec_get_nth_field(rec, i, &len);
-		
+
+		/* Note that prefix indexes are not fixed size even when
+		their type is CHAR. */
+
 		if ((dict_index_get_nth_field(index, i)->prefix_len == 0
 		    && len != UNIV_SQL_NULL && dtype_is_fixed_size(type)
 		    && len != dtype_get_fixed_size(type))
 		   ||
 		   (dict_index_get_nth_field(index, i)->prefix_len > 0
-		    && len != UNIV_SQL_NULL && dtype_is_fixed_size(type)
-		    && len !=
+		    && len != UNIV_SQL_NULL
+		    && len >
 			   dict_index_get_nth_field(index, i)->prefix_len)) {
 
 			btr_index_rec_validate_report(page, rec, index);
diff --git a/innobase/rem/rem0cmp.c b/innobase/rem/rem0cmp.c
index f6c82102839..041fb7914e2 100644
--- a/innobase/rem/rem0cmp.c
+++ b/innobase/rem/rem0cmp.c
@@ -14,9 +14,6 @@ Created 7/1/1994 Heikki Tuuri
 
 #include "srv0srv.h"
 
-#include <m_ctype.h>
-#include <my_sys.h>
-
 /*		ALPHABETICAL ORDER
 		==================
 		
@@ -455,8 +452,6 @@ cmp_dtuple_rec_with_match(
 	ulint		cur_bytes; 	/* number of already matched bytes 
 					in current field */
 	int		ret = 3333;	/* return value */
-	
-	CHARSET_INFO*   charset;        /* charset used in the field */
 
 	ut_ad(dtuple && rec && matched_fields && matched_bytes);
 	ut_ad(dtuple_check_typed(dtuple));
@@ -546,33 +541,8 @@ cmp_dtuple_rec_with_match(
 			&& dtype_get_charset_coll(cur_type->prtype) !=
 				data_mysql_latin1_swedish_charset_coll)) {
 
-		  	/* If character set is not latin1_swedish
-			we have to devide character length by the
-			maximum bytes needed for that character
-			set. For example if we have unique prefix
-			index for 1 utf8 character then we have
-			actually 3 bytes allocated in the index.
-			Therefore, we have to divide that with
-			maximum bytes needed for utf8 character i.e.
-			3 byges.*/
-
-                        if ( dtuple_f_len > 0) {
-			  charset = get_charset(
-				dtype_get_charset_coll(cur_type->prtype), 
-				MYF(MY_WME));
-
-			  ut_ad(charset);
-			  ut_ad(charset->mbmaxlen);
-
-			  dtuple_f_len = dtuple_f_len / charset->mbmaxlen;
-
-                          if ( dtuple_f_len == 0)
-			    dtuple_f_len = 1;
-
-			  rec_f_len = dtuple_f_len;
-			} 
-
-			ret = cmp_whole_field(cur_type,
+			ret = cmp_whole_field(
+				cur_type,
 				dfield_get_data(dtuple_field), dtuple_f_len,
 				rec_b_ptr, rec_f_len);
 
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;
 		}
diff --git a/innobase/row/row0row.c b/innobase/row/row0row.c
index 680539764fd..ed6462b7377 100644
--- a/innobase/row/row0row.c
+++ b/innobase/row/row0row.c
@@ -113,6 +113,8 @@ row_build_index_entry(
 	dfield_t*	dfield2;
 	dict_col_t*	col;
 	ulint		i;
+        ulint           storage_len;
+	dtype_t*	cur_type;
 
 	ut_ad(row && index && heap);
 	ut_ad(dtuple_check_typed(row));
@@ -139,10 +141,20 @@ row_build_index_entry(
 
 		/* If a column prefix index, take only the prefix */
 		if (ind_field->prefix_len > 0
-		    && dfield_get_len(dfield2) != UNIV_SQL_NULL
-		    && dfield_get_len(dfield2) > ind_field->prefix_len) {
+		    && dfield_get_len(dfield2) != UNIV_SQL_NULL) {
 			
-			dfield_set_len(dfield, ind_field->prefix_len);
+			/* For prefix keys get the storage length
+			for the prefix_len characters. */
+
+			cur_type = dict_col_get_type(
+				dict_field_get_col(ind_field));
+
+			storage_len = innobase_get_at_most_n_mbchars(
+				dtype_get_charset_coll(cur_type->prtype),
+				ind_field->prefix_len,
+				dfield_get_len(dfield2),dfield2->data);
+
+			dfield_set_len(dfield,storage_len);
 		}
 	}
 
@@ -460,6 +472,7 @@ row_build_row_ref_from_row(
 	dict_col_t*	col;
 	ulint		ref_len;
 	ulint		i;
+	dtype_t*	cur_type;
 	
 	ut_ad(ref && table && row);
 		
@@ -481,10 +494,18 @@ row_build_row_ref_from_row(
 		dfield_copy(dfield, dfield2);
 
 		if (field->prefix_len > 0
-		    && dfield->len != UNIV_SQL_NULL
-		    && dfield->len > field->prefix_len) {
+		    && dfield->len != 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(field));
 
-		        dfield->len = field->prefix_len;
+			dfield->len = innobase_get_at_most_n_mbchars(
+				dtype_get_charset_coll(cur_type->prtype),
+				field->prefix_len,
+				dfield->len,dfield->data);
 		}
 	}
 
diff --git a/innobase/row/row0sel.c b/innobase/row/row0sel.c
index 2c0092adc6e..d87cc857651 100644
--- a/innobase/row/row0sel.c
+++ b/innobase/row/row0sel.c
@@ -76,6 +76,7 @@ row_sel_sec_rec_is_for_clust_rec(
         ulint           clust_len;
         ulint           n;
         ulint           i;
+	dtype_t*	cur_type;
 
 	UT_NOT_USED(clust_index);
 
@@ -91,10 +92,18 @@ row_sel_sec_rec_is_for_clust_rec(
                 sec_field = rec_get_nth_field(sec_rec, i, &sec_len);
 
 		if (ifield->prefix_len > 0
-		    && clust_len != UNIV_SQL_NULL
-		    && clust_len > ifield->prefix_len) {
+		    && clust_len != UNIV_SQL_NULL) {
 
-		       clust_len = ifield->prefix_len;
+			/* For prefix keys get the storage length
+			for the prefix_len characters. */
+
+			cur_type = dict_col_get_type(
+				dict_field_get_col(ifield));
+
+			clust_len = innobase_get_at_most_n_mbchars(
+				dtype_get_charset_coll(cur_type->prtype),
+				ifield->prefix_len,
+				clust_len,clust_field);
 		}
 
                 if (0 != cmp_data_data(dict_col_get_type(col),
diff --git a/innobase/row/row0upd.c b/innobase/row/row0upd.c
index d35ae0a3e38..75400e06059 100644
--- a/innobase/row/row0upd.c
+++ b/innobase/row/row0upd.c
@@ -842,6 +842,7 @@ row_upd_index_replace_new_col_vals_index_pos(
 	dfield_t*	new_val;
 	ulint		j;
 	ulint		i;
+	dtype_t*	cur_type;
 
 	ut_ad(index);
 
@@ -871,10 +872,19 @@ row_upd_index_replace_new_col_vals_index_pos(
 				}
 
 				if (field->prefix_len > 0
-			            && new_val->len != UNIV_SQL_NULL
-			            && new_val->len > field->prefix_len) {
+			            && new_val->len != UNIV_SQL_NULL) {
 
-				        dfield->len = field->prefix_len;
+				/* For prefix keys get the storage length
+				for the prefix_len characters. */
+
+				  cur_type = dict_col_get_type(
+					dict_field_get_col(field));
+
+				  dfield->len = 
+				    innobase_get_at_most_n_mbchars(
+				      dtype_get_charset_coll(cur_type->prtype),
+					field->prefix_len,
+					new_val->len,new_val->data);
 				}
 			}
 		}
@@ -904,6 +914,7 @@ row_upd_index_replace_new_col_vals(
 	dfield_t*	new_val;
 	ulint		j;
 	ulint		i;
+	dtype_t*	cur_type;
 
 	ut_ad(index);
 
@@ -933,10 +944,19 @@ row_upd_index_replace_new_col_vals(
 				}
 
 				if (field->prefix_len > 0
-			            && new_val->len != UNIV_SQL_NULL
-			            && new_val->len > field->prefix_len) {
+			            && new_val->len != 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(field));
 
-				        dfield->len = field->prefix_len;
+				  dfield->len = 
+				    innobase_get_at_most_n_mbchars(
+				      dtype_get_charset_coll(cur_type->prtype),
+					field->prefix_len,
+					new_val->len,new_val->data);
 				}
 			}
 		}