bug #5723 length(varchar utf8 field) returns verying results

mysql-test/r/bdb.result

@@ -1251,3 +1251,12 @@ truncate t1;
 select * from t1;
 a	b
 drop table t1;
+SET NAMES utf8;
+create table t1 (a varchar(255) character set utf8) engine=bdb;
+set @a:= convert(repeat(_latin1 0xFF, 255) using utf8);
+insert into t1 values (@a);
+select a, length(a), char_length(a) from t1;
+a	length(a)	char_length(a)
+ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ	510	255
+drop table t1;
+SET NAMES latin1;

mysql-test/r/ctype_utf8.result

@@ -644,3 +644,19 @@ INSERT INTO t1 VALUES ('test');
 SELECT a FROM t1 WHERE a LIKE '%te';
 a
 DROP TABLE t1;
+SET NAMES utf8;
+CREATE TABLE t1 (
+subject varchar(255) character set utf8 collate utf8_unicode_ci,
+p varchar(15) character set utf8
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES ('谷川俊二と申しますが、インターネット予約の会員登録をしましたところ、メールアドレスを間違えてしまい会員ＩＤが受け取ることが出来ませんでした。間違えアドレスはtani-shun@n.vodafone.ne.jpを書き込みました。どうすればよいですか？ その他、住所等は間違えありません。連絡ください。よろしくお願いします。m(__)m','040312-000057');
+INSERT INTO t1 VALUES ('aaa','bbb');
+SELECT length(subject) FROM t1;
+length(subject)
+432
+3
+SELECT length(subject) FROM t1 ORDER BY 1;
+length(subject)
+3
+432
+DROP TABLE t1;

mysql-test/t/bdb.test

@@ -897,3 +897,15 @@ commit;
 truncate t1;
 select * from t1;
 drop table t1;
+
+#
+# Check that BDB works fine with a string which is
+# longer than 255 bytes for multibyte characters.
+#
+SET NAMES utf8;
+create table t1 (a varchar(255) character set utf8) engine=bdb;
+set @a:= convert(repeat(_latin1 0xFF, 255) using utf8);
+insert into t1 values (@a);
+select a, length(a), char_length(a) from t1;
+drop table t1;
+SET NAMES latin1;

mysql-test/t/ctype_utf8.test

@@ -499,3 +499,17 @@ CREATE TABLE t1 (a varchar(32) BINARY) CHARACTER SET utf8;
 INSERT INTO t1 VALUES ('test');
 SELECT a FROM t1 WHERE a LIKE '%te';
 DROP TABLE t1;
+
+#
+# Bug #5723: length(<varchar utf8 field>) returns varying results
+#
+SET NAMES utf8;
+CREATE TABLE t1 (
+  subject varchar(255) character set utf8 collate utf8_unicode_ci,
+  p varchar(15) character set utf8
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+INSERT INTO t1 VALUES ('谷川俊二と申しますが、インターネット予約の会員登録をしましたところ、メールアドレスを間違えてしまい会員ＩＤが受け取ることが出来ませんでした。間違えアドレスはtani-shun@n.vodafone.ne.jpを書き込みました。どうすればよいですか？ その他、住所等は間違えありません。連絡ください。よろしくお願いします。m(__)m','040312-000057');
+INSERT INTO t1 VALUES ('aaa','bbb');
+SELECT length(subject) FROM t1;
+SELECT length(subject) FROM t1 ORDER BY 1;
+DROP TABLE t1;

sql/field.cc

@@ -4384,12 +4384,19 @@ void Field_string::sql_type(String &res) const
 char *Field_string::pack(char *to, const char *from, uint max_length)
 {
   const char *end=from+min(field_length,max_length);
-  uchar length;
+  uint length;
   while (end > from && end[-1] == ' ')
     end--;
-  *to= length=(uchar) (end-from);
-  memcpy(to+1, from, (int) length);
-  return to+1+length;
+  length= (end-from);
+  if (field_length > 255)
+  {
+    int2store(to, length);
+    to+= 2;
+  }
+  else
+    *to++= (char) (uchar) length;
+  memcpy(to, from, (int) length);
+  return to+length;
 }
 
 
@@ -4402,15 +4409,28 @@ char *Field_string::pack_key(char *to, const char *from, uint max_length)
   set_if_smaller(length, char_length);
   while (length && from[length-1] == ' ')
     length--;
-  *to= (uchar)length;
-  memcpy(to+1, from, length);
-  return to+1+length;
+  if (field_length > 255)
+  {
+    int2store(to, length);
+    to+= 2;
+  }
+  else
+    *to++= (char) (uchar) length;
+  memcpy(to, from, length);
+  return to+length;
 }
 
 
 const char *Field_string::unpack(char *to, const char *from)
 {
-  uint length= (uint) (uchar) *from++;
+  uint length;
+  if (field_length > 255)
+  {
+    length= uint2korr(from);
+    from+= 2;
+  }
+  else
+    length= (uint) (uchar) *from++;
   memcpy(to, from, (int) length);
   bfill(to+length, field_length - length, ' ');
   return from+length;
@@ -4419,8 +4439,19 @@ const char *Field_string::unpack(char *to, const char *from)
 
 int Field_string::pack_cmp(const char *a, const char *b, uint length)
 {
-  uint a_length= (uint) (uchar) *a++;
-  uint b_length= (uint) (uchar) *b++;
+  uint a_length, b_length;
+  if (field_length > 255)
+  {
+    a_length= uint2korr(a);
+    b_length= uint2korr(b);
+    a+= 2;
+    b+= 2;
+  }
+  else
+  {
+    a_length= (uint) (uchar) *a++;
+    b_length= (uint) (uchar) *b++;
+  }
   return my_strnncoll(field_charset,
 		      (const uchar*)a,a_length,
 		      (const uchar*)b,b_length);
@@ -4429,7 +4460,14 @@ int Field_string::pack_cmp(const char *a, const char *b, uint length)
 
 int Field_string::pack_cmp(const char *b, uint length)
 {
-  uint b_length= (uint) (uchar) *b++;
+  uint b_length;
+  if (field_length > 255)
+  {
+    b_length= uint2korr(b);
+    b+= 2;
+  }
+  else
+    b_length= (uint) (uchar) *b++;
   char *end= ptr + field_length;
   while (end > ptr && end[-1] == ' ')
     end--;