Bug #6019 - SELECT tries to use too short prefix index on utf8 data

Field_string::pack should respect max_length as Field_string::pack_key does

mysql-test/r/ctype_utf8.result

@@ -798,4 +798,8 @@ insert into t1 values(1,'foo'),(2,'foobar');
 select * from t1 where b like 'foob%';
 a	b
 2	foobar
+alter table t1 engine=bdb;
+select * from t1 where b like 'foob%';
+a	b
+2	foobar
 drop table t1;

mysql-test/t/ctype_utf8.test

@@ -643,4 +643,8 @@ create table t1 (
 --enable_warnings
 insert into t1 values(1,'foo'),(2,'foobar');
 select * from t1 where b like 'foob%';
+--disable_warnings
+alter table t1 engine=bdb;
+select * from t1 where b like 'foob%';
+--enable_warnings
 drop table t1;

sql/field.cc

@@ -4425,23 +4425,7 @@ void Field_string::sql_type(String &res) const
   res.length(length);
 }
 
-
 char *Field_string::pack(char *to, const char *from, uint max_length)
-{
-  const char *end=from+min(field_length,max_length);
-  uint length;
-  while (end > from && end[-1] == ' ')
-    end--;
-  length= (end-from);
-  *to++= (char) (uchar) length;
-  if (field_length > 255)
-    *to++= (char) (uchar) (length >> 8);
-  memcpy(to, from, (int) length);
-  return to+length;
-}
-
-
-char *Field_string::pack_key(char *to, const char *from, uint max_length)
 {
   uint length=      min(field_length,max_length);
   uint char_length= max_length/field_charset->mbmaxlen;

sql/field.h

@@ -927,7 +927,6 @@ public:
   void sort_string(char *buff,uint length);
   void sql_type(String &str) const;
   char *pack(char *to, const char *from, uint max_length=~(uint) 0);
-  char *pack_key(char *to, const char *from, uint max_length);
   const char *unpack(char* to, const char *from);
   int pack_cmp(const char *a,const char *b,uint key_length);
   int pack_cmp(const char *b,uint key_length);