Bug#7284: strnxfrm generates different results for equal strings

additional fix for cp932 and eucjpms, recently implemented by
Shuichi.

mysql-test/r/ctype_cp932.result

@@ -11315,3 +11315,23 @@ DROP TABLE t1;
 DROP TABLE t2;
 DROP TABLE t3;
 DROP TABLE t4;
+SET collation_connection='cp932_japanese_ci';
+create table t1 select repeat('a',4000) a;
+delete from t1;
+insert into t1 values ('a'), ('a '), ('a\t');
+select collation(a),hex(a) from t1 order by a;
+collation(a)	hex(a)
+cp932_japanese_ci	6109
+cp932_japanese_ci	61
+cp932_japanese_ci	6120
+drop table t1;
+SET collation_connection='cp932_bin';
+create table t1 select repeat('a',4000) a;
+delete from t1;
+insert into t1 values ('a'), ('a '), ('a\t');
+select collation(a),hex(a) from t1 order by a;
+collation(a)	hex(a)
+cp932_bin	6109
+cp932_bin	61
+cp932_bin	6120
+drop table t1;

mysql-test/r/ctype_eucjpms.result

@@ -9785,3 +9785,23 @@ DROP TABLE t1;
 DROP TABLE t2;
 DROP TABLE t3;
 DROP TABLE t4;
+SET collation_connection='eucjpms_japanese_ci';
+create table t1 select repeat('a',4000) a;
+delete from t1;
+insert into t1 values ('a'), ('a '), ('a\t');
+select collation(a),hex(a) from t1 order by a;
+collation(a)	hex(a)
+eucjpms_japanese_ci	6109
+eucjpms_japanese_ci	61
+eucjpms_japanese_ci	6120
+drop table t1;
+SET collation_connection='eucjpms_bin';
+create table t1 select repeat('a',4000) a;
+delete from t1;
+insert into t1 values ('a'), ('a '), ('a\t');
+select collation(a),hex(a) from t1 order by a;
+collation(a)	hex(a)
+eucjpms_bin	6109
+eucjpms_bin	61
+eucjpms_bin	6120
+drop table t1;

mysql-test/t/ctype_cp932.test

@@ -395,3 +395,9 @@ DROP TABLE t1;
 DROP TABLE t2;
 DROP TABLE t3;
 DROP TABLE t4;
+
+
+SET collation_connection='cp932_japanese_ci';
+-- source include/ctype_filesort.inc
+SET collation_connection='cp932_bin';
+-- source include/ctype_filesort.inc

mysql-test/t/ctype_eucjpms.test

@@ -342,3 +342,9 @@ DROP TABLE t1;
 DROP TABLE t2;
 DROP TABLE t3;
 DROP TABLE t4;
+
+
+SET collation_connection='eucjpms_japanese_ci';
+-- source include/ctype_filesort.inc
+SET collation_connection='eucjpms_bin';
+-- source include/ctype_filesort.inc

strings/ctype-cp932.c

@@ -244,7 +244,8 @@ static int my_strnncoll_cp932(CHARSET_INFO *cs __attribute__((unused)),
 
 static int my_strnncollsp_cp932(CHARSET_INFO *cs __attribute__((unused)),
 			       const uchar *a, uint a_length, 
-			       const uchar *b, uint b_length)
+			       const uchar *b, uint b_length,
+			       my_bool diff_end_space __attribute__((unused)))
 {
   const uchar *a_end= a + a_length;
   const uchar *b_end= b + b_length;
@@ -291,7 +292,9 @@ static int my_strnxfrm_cp932(CHARSET_INFO *cs __attribute__((unused)),
     else
       *dest++ = sort_order_cp932[(uchar)*src++];
   }
-  return srclen;
+  if (len > srclen)
+    bfill(dest, len - srclen, ' ');
+  return len;
 }